granicus.if.org Git - postgresql/blob - src/backend/utils/misc/guc.c

   1 /*--------------------------------------------------------------------
   2  * guc.c
   3  *
   4  * Support for grand unified configuration scheme, including SET
   5  * command, configuration file, and command line options.
   6  * See src/backend/utils/misc/README for more information.
   7  *
   8  *
   9  * Copyright (c) 2000-2011, PostgreSQL Global Development Group
  10  * Written by Peter Eisentraut <peter_e@gmx.net>.
  11  *
  12  * IDENTIFICATION
  13  *        src/backend/utils/misc/guc.c
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <math.h>
  22 #include <limits.h>
  23 #include <unistd.h>
  24 #include <sys/stat.h>
  25 #ifdef HAVE_SYSLOG
  26 #include <syslog.h>
  27 #endif
  28
  29 #include "access/gin.h"
  30 #include "access/transam.h"
  31 #include "access/twophase.h"
  32 #include "access/xact.h"
  33 #include "catalog/namespace.h"
  34 #include "commands/async.h"
  35 #include "commands/prepare.h"
  36 #include "commands/vacuum.h"
  37 #include "commands/variable.h"
  38 #include "commands/trigger.h"
  39 #include "funcapi.h"
  40 #include "libpq/auth.h"
  41 #include "libpq/be-fsstubs.h"
  42 #include "libpq/pqformat.h"
  43 #include "miscadmin.h"
  44 #include "optimizer/cost.h"
  45 #include "optimizer/geqo.h"
  46 #include "optimizer/paths.h"
  47 #include "optimizer/planmain.h"
  48 #include "parser/parse_expr.h"
  49 #include "parser/parse_type.h"
  50 #include "parser/parser.h"
  51 #include "parser/scansup.h"
  52 #include "pgstat.h"
  53 #include "postmaster/autovacuum.h"
  54 #include "postmaster/bgwriter.h"
  55 #include "postmaster/postmaster.h"
  56 #include "postmaster/syslogger.h"
  57 #include "postmaster/walwriter.h"
  58 #include "replication/syncrep.h"
  59 #include "replication/walreceiver.h"
  60 #include "replication/walsender.h"
  61 #include "storage/bufmgr.h"
  62 #include "storage/standby.h"
  63 #include "storage/fd.h"
  64 #include "storage/predicate.h"
  65 #include "tcop/tcopprot.h"
  66 #include "tsearch/ts_cache.h"
  67 #include "utils/builtins.h"
  68 #include "utils/bytea.h"
  69 #include "utils/guc_tables.h"
  70 #include "utils/memutils.h"
  71 #include "utils/pg_locale.h"
  72 #include "utils/plancache.h"
  73 #include "utils/portal.h"
  74 #include "utils/ps_status.h"
  75 #include "utils/tzparser.h"
  76 #include "utils/xml.h"
  77
  78 #ifndef PG_KRB_SRVTAB
  79 #define PG_KRB_SRVTAB ""
  80 #endif
  81 #ifndef PG_KRB_SRVNAM
  82 #define PG_KRB_SRVNAM ""
  83 #endif
  84
  85 #define CONFIG_FILENAME "postgresql.conf"
  86 #define HBA_FILENAME    "pg_hba.conf"
  87 #define IDENT_FILENAME  "pg_ident.conf"
  88
  89 #ifdef EXEC_BACKEND
  90 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  91 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  92 #endif
  93
  94 /* upper limit for GUC variables measured in kilobytes of memory */
  95 /* note that various places assume the byte size fits in a "long" variable */
  96 #if SIZEOF_SIZE_T > 4 && SIZEOF_LONG > 4
  97 #define MAX_KILOBYTES   INT_MAX
  98 #else
  99 #define MAX_KILOBYTES   (INT_MAX / 1024)
 100 #endif
 101
 102 /*
 103  * Note: MAX_BACKENDS is limited to 2^23-1 because inval.c stores the
 104  * backend ID as a 3-byte signed integer.  Even if that limitation were
 105  * removed, we still could not exceed INT_MAX/4 because some places compute
 106  * 4*MaxBackends without any overflow check.  This is rechecked in
 107  * check_maxconnections, since MaxBackends is computed as MaxConnections
 108  * plus autovacuum_max_workers plus one (for the autovacuum launcher).
 109  */
 110 #define MAX_BACKENDS    0x7fffff
 111
 112 #define KB_PER_MB (1024)
 113 #define KB_PER_GB (1024*1024)
 114
 115 #define MS_PER_S 1000
 116 #define S_PER_MIN 60
 117 #define MS_PER_MIN (1000 * 60)
 118 #define MIN_PER_H 60
 119 #define S_PER_H (60 * 60)
 120 #define MS_PER_H (1000 * 60 * 60)
 121 #define MIN_PER_D (60 * 24)
 122 #define S_PER_D (60 * 60 * 24)
 123 #define MS_PER_D (1000 * 60 * 60 * 24)
 124
 125 /* XXX these should appear in other modules' header files */
 126 extern bool Log_disconnections;
 127 extern int      CommitDelay;
 128 extern int      CommitSiblings;
 129 extern char *default_tablespace;
 130 extern char *temp_tablespaces;
 131 extern bool synchronize_seqscans;
 132 extern bool fullPageWrites;
 133 extern int      ssl_renegotiation_limit;
 134 extern char *SSLCipherSuites;
 135
 136 #ifdef TRACE_SORT
 137 extern bool trace_sort;
 138 #endif
 139 #ifdef TRACE_SYNCSCAN
 140 extern bool trace_syncscan;
 141 #endif
 142 #ifdef DEBUG_BOUNDED_SORT
 143 extern bool optimize_bounded_sort;
 144 #endif
 145
 146 static int      GUC_check_errcode_value;
 147
 148 /* global variables for check hook support */
 149 char       *GUC_check_errmsg_string;
 150 char       *GUC_check_errdetail_string;
 151 char       *GUC_check_errhint_string;
 152
 153
 154 static void set_config_sourcefile(const char *name, char *sourcefile,
 155                                           int sourceline);
 156 static bool call_bool_check_hook(struct config_bool * conf, bool *newval,
 157                                          void **extra, GucSource source, int elevel);
 158 static bool call_int_check_hook(struct config_int * conf, int *newval,
 159                                         void **extra, GucSource source, int elevel);
 160 static bool call_real_check_hook(struct config_real * conf, double *newval,
 161                                          void **extra, GucSource source, int elevel);
 162 static bool call_string_check_hook(struct config_string * conf, char **newval,
 163                                            void **extra, GucSource source, int elevel);
 164 static bool call_enum_check_hook(struct config_enum * conf, int *newval,
 165                                          void **extra, GucSource source, int elevel);
 166
 167 static bool check_log_destination(char **newval, void **extra, GucSource source);
 168 static void assign_log_destination(const char *newval, void *extra);
 169
 170 #ifdef HAVE_SYSLOG
 171 static int      syslog_facility = LOG_LOCAL0;
 172 #else
 173 static int      syslog_facility = 0;
 174 #endif
 175
 176 static void assign_syslog_facility(int newval, void *extra);
 177 static void assign_syslog_ident(const char *newval, void *extra);
 178 static void assign_session_replication_role(int newval, void *extra);
 179 static bool check_temp_buffers(int *newval, void **extra, GucSource source);
 180 static bool check_phony_autocommit(bool *newval, void **extra, GucSource source);
 181 static bool check_debug_assertions(bool *newval, void **extra, GucSource source);
 182 static bool check_bonjour(bool *newval, void **extra, GucSource source);
 183 static bool check_ssl(bool *newval, void **extra, GucSource source);
 184 static bool check_stage_log_stats(bool *newval, void **extra, GucSource source);
 185 static bool check_log_stats(bool *newval, void **extra, GucSource source);
 186 static bool check_canonical_path(char **newval, void **extra, GucSource source);
 187 static bool check_timezone_abbreviations(char **newval, void **extra, GucSource source);
 188 static void assign_timezone_abbreviations(const char *newval, void *extra);
 189 static void pg_timezone_abbrev_initialize(void);
 190 static const char *show_archive_command(void);
 191 static void assign_tcp_keepalives_idle(int newval, void *extra);
 192 static void assign_tcp_keepalives_interval(int newval, void *extra);
 193 static void assign_tcp_keepalives_count(int newval, void *extra);
 194 static const char *show_tcp_keepalives_idle(void);
 195 static const char *show_tcp_keepalives_interval(void);
 196 static const char *show_tcp_keepalives_count(void);
 197 static bool check_maxconnections(int *newval, void **extra, GucSource source);
 198 static void assign_maxconnections(int newval, void *extra);
 199 static bool check_autovacuum_max_workers(int *newval, void **extra, GucSource source);
 200 static void assign_autovacuum_max_workers(int newval, void *extra);
 201 static bool check_effective_io_concurrency(int *newval, void **extra, GucSource source);
 202 static void assign_effective_io_concurrency(int newval, void *extra);
 203 static void assign_pgstat_temp_directory(const char *newval, void *extra);
 204 static bool check_application_name(char **newval, void **extra, GucSource source);
 205 static void assign_application_name(const char *newval, void *extra);
 206 static const char *show_unix_socket_permissions(void);
 207 static const char *show_log_file_mode(void);
 208
 209 static char *config_enum_get_options(struct config_enum * record,
 210                                                 const char *prefix, const char *suffix,
 211                                                 const char *separator);
 212
 213
 214 /*
 215  * Options for enum values defined in this module.
 216  *
 217  * NOTE! Option values may not contain double quotes!
 218  */
 219
 220 static const struct config_enum_entry bytea_output_options[] = {
 221         {"escape", BYTEA_OUTPUT_ESCAPE, false},
 222         {"hex", BYTEA_OUTPUT_HEX, false},
 223         {NULL, 0, false}
 224 };
 225
 226 /*
 227  * We have different sets for client and server message level options because
 228  * they sort slightly different (see "log" level)
 229  */
 230 static const struct config_enum_entry client_message_level_options[] = {
 231         {"debug", DEBUG2, true},
 232         {"debug5", DEBUG5, false},
 233         {"debug4", DEBUG4, false},
 234         {"debug3", DEBUG3, false},
 235         {"debug2", DEBUG2, false},
 236         {"debug1", DEBUG1, false},
 237         {"log", LOG, false},
 238         {"info", INFO, true},
 239         {"notice", NOTICE, false},
 240         {"warning", WARNING, false},
 241         {"error", ERROR, false},
 242         {"fatal", FATAL, true},
 243         {"panic", PANIC, true},
 244         {NULL, 0, false}
 245 };
 246
 247 static const struct config_enum_entry server_message_level_options[] = {
 248         {"debug", DEBUG2, true},
 249         {"debug5", DEBUG5, false},
 250         {"debug4", DEBUG4, false},
 251         {"debug3", DEBUG3, false},
 252         {"debug2", DEBUG2, false},
 253         {"debug1", DEBUG1, false},
 254         {"info", INFO, false},
 255         {"notice", NOTICE, false},
 256         {"warning", WARNING, false},
 257         {"error", ERROR, false},
 258         {"log", LOG, false},
 259         {"fatal", FATAL, false},
 260         {"panic", PANIC, false},
 261         {NULL, 0, false}
 262 };
 263
 264 static const struct config_enum_entry intervalstyle_options[] = {
 265         {"postgres", INTSTYLE_POSTGRES, false},
 266         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 267         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 268         {"iso_8601", INTSTYLE_ISO_8601, false},
 269         {NULL, 0, false}
 270 };
 271
 272 static const struct config_enum_entry log_error_verbosity_options[] = {
 273         {"terse", PGERROR_TERSE, false},
 274         {"default", PGERROR_DEFAULT, false},
 275         {"verbose", PGERROR_VERBOSE, false},
 276         {NULL, 0, false}
 277 };
 278
 279 static const struct config_enum_entry log_statement_options[] = {
 280         {"none", LOGSTMT_NONE, false},
 281         {"ddl", LOGSTMT_DDL, false},
 282         {"mod", LOGSTMT_MOD, false},
 283         {"all", LOGSTMT_ALL, false},
 284         {NULL, 0, false}
 285 };
 286
 287 static const struct config_enum_entry isolation_level_options[] = {
 288         {"serializable", XACT_SERIALIZABLE, false},
 289         {"repeatable read", XACT_REPEATABLE_READ, false},
 290         {"read committed", XACT_READ_COMMITTED, false},
 291         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 292         {NULL, 0}
 293 };
 294
 295 static const struct config_enum_entry session_replication_role_options[] = {
 296         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 297         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 298         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 299         {NULL, 0, false}
 300 };
 301
 302 static const struct config_enum_entry syslog_facility_options[] = {
 303 #ifdef HAVE_SYSLOG
 304         {"local0", LOG_LOCAL0, false},
 305         {"local1", LOG_LOCAL1, false},
 306         {"local2", LOG_LOCAL2, false},
 307         {"local3", LOG_LOCAL3, false},
 308         {"local4", LOG_LOCAL4, false},
 309         {"local5", LOG_LOCAL5, false},
 310         {"local6", LOG_LOCAL6, false},
 311         {"local7", LOG_LOCAL7, false},
 312 #else
 313         {"none", 0, false},
 314 #endif
 315         {NULL, 0}
 316 };
 317
 318 static const struct config_enum_entry track_function_options[] = {
 319         {"none", TRACK_FUNC_OFF, false},
 320         {"pl", TRACK_FUNC_PL, false},
 321         {"all", TRACK_FUNC_ALL, false},
 322         {NULL, 0, false}
 323 };
 324
 325 static const struct config_enum_entry xmlbinary_options[] = {
 326         {"base64", XMLBINARY_BASE64, false},
 327         {"hex", XMLBINARY_HEX, false},
 328         {NULL, 0, false}
 329 };
 330
 331 static const struct config_enum_entry xmloption_options[] = {
 332         {"content", XMLOPTION_CONTENT, false},
 333         {"document", XMLOPTION_DOCUMENT, false},
 334         {NULL, 0, false}
 335 };
 336
 337 /*
 338  * Although only "on", "off", and "safe_encoding" are documented, we
 339  * accept all the likely variants of "on" and "off".
 340  */
 341 static const struct config_enum_entry backslash_quote_options[] = {
 342         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 343         {"on", BACKSLASH_QUOTE_ON, false},
 344         {"off", BACKSLASH_QUOTE_OFF, false},
 345         {"true", BACKSLASH_QUOTE_ON, true},
 346         {"false", BACKSLASH_QUOTE_OFF, true},
 347         {"yes", BACKSLASH_QUOTE_ON, true},
 348         {"no", BACKSLASH_QUOTE_OFF, true},
 349         {"1", BACKSLASH_QUOTE_ON, true},
 350         {"0", BACKSLASH_QUOTE_OFF, true},
 351         {NULL, 0, false}
 352 };
 353
 354 /*
 355  * Although only "on", "off", and "partition" are documented, we
 356  * accept all the likely variants of "on" and "off".
 357  */
 358 static const struct config_enum_entry constraint_exclusion_options[] = {
 359         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 360         {"on", CONSTRAINT_EXCLUSION_ON, false},
 361         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 362         {"true", CONSTRAINT_EXCLUSION_ON, true},
 363         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 364         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 365         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 366         {"1", CONSTRAINT_EXCLUSION_ON, true},
 367         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 368         {NULL, 0, false}
 369 };
 370
 371 /*
 372  * Although only "on", "off", and "local" are documented, we
 373  * accept all the likely variants of "on" and "off".
 374  */
 375 static const struct config_enum_entry synchronous_commit_options[] = {
 376         {"local", SYNCHRONOUS_COMMIT_LOCAL_FLUSH, false},
 377         {"on", SYNCHRONOUS_COMMIT_ON, false},
 378         {"off", SYNCHRONOUS_COMMIT_OFF, false},
 379         {"true", SYNCHRONOUS_COMMIT_ON, true},
 380         {"false", SYNCHRONOUS_COMMIT_OFF, true},
 381         {"yes", SYNCHRONOUS_COMMIT_ON, true},
 382         {"no", SYNCHRONOUS_COMMIT_OFF, true},
 383         {"1", SYNCHRONOUS_COMMIT_ON, true},
 384         {"0", SYNCHRONOUS_COMMIT_OFF, true},
 385         {NULL, 0, false}
 386 };
 387
 388 /*
 389  * Options for enum values stored in other modules
 390  */
 391 extern const struct config_enum_entry wal_level_options[];
 392 extern const struct config_enum_entry sync_method_options[];
 393
 394 /*
 395  * GUC option variables that are exported from this module
 396  */
 397 #ifdef USE_ASSERT_CHECKING
 398 bool            assert_enabled = true;
 399 #else
 400 bool            assert_enabled = false;
 401 #endif
 402 bool            log_duration = false;
 403 bool            Debug_print_plan = false;
 404 bool            Debug_print_parse = false;
 405 bool            Debug_print_rewritten = false;
 406 bool            Debug_pretty_print = true;
 407
 408 bool            log_parser_stats = false;
 409 bool            log_planner_stats = false;
 410 bool            log_executor_stats = false;
 411 bool            log_statement_stats = false;            /* this is sort of all three
 412                                                                                                  * above together */
 413 bool            log_btree_build_stats = false;
 414
 415 bool            check_function_bodies = true;
 416 bool            default_with_oids = false;
 417 bool            SQL_inheritance = true;
 418
 419 bool            Password_encryption = true;
 420
 421 int                     log_min_error_statement = ERROR;
 422 int                     log_min_messages = WARNING;
 423 int                     client_min_messages = NOTICE;
 424 int                     log_min_duration_statement = -1;
 425 int                     log_temp_files = -1;
 426 int                     trace_recovery_messages = LOG;
 427
 428 int                     temp_file_limit = -1;
 429
 430 int                     num_temp_buffers = 1024;
 431
 432 char       *data_directory;
 433 char       *ConfigFileName;
 434 char       *HbaFileName;
 435 char       *IdentFileName;
 436 char       *external_pid_file;
 437
 438 char       *pgstat_temp_directory;
 439
 440 char       *application_name;
 441
 442 int                     tcp_keepalives_idle;
 443 int                     tcp_keepalives_interval;
 444 int                     tcp_keepalives_count;
 445
 446 /*
 447  * These variables are all dummies that don't do anything, except in some
 448  * cases provide the value for SHOW to display.  The real state is elsewhere
 449  * and is kept in sync by assign_hooks.
 450  */
 451 static char *log_destination_string;
 452
 453 static char *syslog_ident_str;
 454 static bool phony_autocommit;
 455 static bool session_auth_is_superuser;
 456 static double phony_random_seed;
 457 static char *client_encoding_string;
 458 static char *datestyle_string;
 459 static char *locale_collate;
 460 static char *locale_ctype;
 461 static char *server_encoding_string;
 462 static char *server_version_string;
 463 static int      server_version_num;
 464 static char *timezone_string;
 465 static char *log_timezone_string;
 466 static char *timezone_abbreviations_string;
 467 static char *XactIsoLevel_string;
 468 static char *session_authorization_string;
 469 static int      max_function_args;
 470 static int      max_index_keys;
 471 static int      max_identifier_length;
 472 static int      block_size;
 473 static int      segment_size;
 474 static int      wal_block_size;
 475 static int      wal_segment_size;
 476 static bool integer_datetimes;
 477 static int      effective_io_concurrency;
 478
 479 /* should be static, but commands/variable.c needs to get at this */
 480 char       *role_string;
 481
 482
 483 /*
 484  * Displayable names for context types (enum GucContext)
 485  *
 486  * Note: these strings are deliberately not localized.
 487  */
 488 const char *const GucContext_Names[] =
 489 {
 490          /* PGC_INTERNAL */ "internal",
 491          /* PGC_POSTMASTER */ "postmaster",
 492          /* PGC_SIGHUP */ "sighup",
 493          /* PGC_BACKEND */ "backend",
 494          /* PGC_SUSET */ "superuser",
 495          /* PGC_USERSET */ "user"
 496 };
 497
 498 /*
 499  * Displayable names for source types (enum GucSource)
 500  *
 501  * Note: these strings are deliberately not localized.
 502  */
 503 const char *const GucSource_Names[] =
 504 {
 505          /* PGC_S_DEFAULT */ "default",
 506          /* PGC_S_DYNAMIC_DEFAULT */ "default",
 507          /* PGC_S_ENV_VAR */ "environment variable",
 508          /* PGC_S_FILE */ "configuration file",
 509          /* PGC_S_ARGV */ "command line",
 510          /* PGC_S_DATABASE */ "database",
 511          /* PGC_S_USER */ "user",
 512          /* PGC_S_DATABASE_USER */ "database user",
 513          /* PGC_S_CLIENT */ "client",
 514          /* PGC_S_OVERRIDE */ "override",
 515          /* PGC_S_INTERACTIVE */ "interactive",
 516          /* PGC_S_TEST */ "test",
 517          /* PGC_S_SESSION */ "session"
 518 };
 519
 520 /*
 521  * Displayable names for the groupings defined in enum config_group
 522  */
 523 const char *const config_group_names[] =
 524 {
 525         /* UNGROUPED */
 526         gettext_noop("Ungrouped"),
 527         /* FILE_LOCATIONS */
 528         gettext_noop("File Locations"),
 529         /* CONN_AUTH */
 530         gettext_noop("Connections and Authentication"),
 531         /* CONN_AUTH_SETTINGS */
 532         gettext_noop("Connections and Authentication / Connection Settings"),
 533         /* CONN_AUTH_SECURITY */
 534         gettext_noop("Connections and Authentication / Security and Authentication"),
 535         /* RESOURCES */
 536         gettext_noop("Resource Usage"),
 537         /* RESOURCES_MEM */
 538         gettext_noop("Resource Usage / Memory"),
 539         /* RESOURCES_DISK */
 540         gettext_noop("Resource Usage / Disk"),
 541         /* RESOURCES_KERNEL */
 542         gettext_noop("Resource Usage / Kernel Resources"),
 543         /* RESOURCES_VACUUM_DELAY */
 544         gettext_noop("Resource Usage / Cost-Based Vacuum Delay"),
 545         /* RESOURCES_BGWRITER */
 546         gettext_noop("Resource Usage / Background Writer"),
 547         /* RESOURCES_ASYNCHRONOUS */
 548         gettext_noop("Resource Usage / Asynchronous Behavior"),
 549         /* WAL */
 550         gettext_noop("Write-Ahead Log"),
 551         /* WAL_SETTINGS */
 552         gettext_noop("Write-Ahead Log / Settings"),
 553         /* WAL_CHECKPOINTS */
 554         gettext_noop("Write-Ahead Log / Checkpoints"),
 555         /* WAL_ARCHIVING */
 556         gettext_noop("Write-Ahead Log / Archiving"),
 557         /* REPLICATION */
 558         gettext_noop("Replication"),
 559         /* REPLICATION_SENDING */
 560         gettext_noop("Replication / Sending Servers"),
 561         /* REPLICATION_MASTER */
 562         gettext_noop("Replication / Master Server"),
 563         /* REPLICATION_STANDBY */
 564         gettext_noop("Replication / Standby Servers"),
 565         /* QUERY_TUNING */
 566         gettext_noop("Query Tuning"),
 567         /* QUERY_TUNING_METHOD */
 568         gettext_noop("Query Tuning / Planner Method Configuration"),
 569         /* QUERY_TUNING_COST */
 570         gettext_noop("Query Tuning / Planner Cost Constants"),
 571         /* QUERY_TUNING_GEQO */
 572         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 573         /* QUERY_TUNING_OTHER */
 574         gettext_noop("Query Tuning / Other Planner Options"),
 575         /* LOGGING */
 576         gettext_noop("Reporting and Logging"),
 577         /* LOGGING_WHERE */
 578         gettext_noop("Reporting and Logging / Where to Log"),
 579         /* LOGGING_WHEN */
 580         gettext_noop("Reporting and Logging / When to Log"),
 581         /* LOGGING_WHAT */
 582         gettext_noop("Reporting and Logging / What to Log"),
 583         /* STATS */
 584         gettext_noop("Statistics"),
 585         /* STATS_MONITORING */
 586         gettext_noop("Statistics / Monitoring"),
 587         /* STATS_COLLECTOR */
 588         gettext_noop("Statistics / Query and Index Statistics Collector"),
 589         /* AUTOVACUUM */
 590         gettext_noop("Autovacuum"),
 591         /* CLIENT_CONN */
 592         gettext_noop("Client Connection Defaults"),
 593         /* CLIENT_CONN_STATEMENT */
 594         gettext_noop("Client Connection Defaults / Statement Behavior"),
 595         /* CLIENT_CONN_LOCALE */
 596         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 597         /* CLIENT_CONN_OTHER */
 598         gettext_noop("Client Connection Defaults / Other Defaults"),
 599         /* LOCK_MANAGEMENT */
 600         gettext_noop("Lock Management"),
 601         /* COMPAT_OPTIONS */
 602         gettext_noop("Version and Platform Compatibility"),
 603         /* COMPAT_OPTIONS_PREVIOUS */
 604         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 605         /* COMPAT_OPTIONS_CLIENT */
 606         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 607         /* ERROR_HANDLING */
 608         gettext_noop("Error Handling"),
 609         /* PRESET_OPTIONS */
 610         gettext_noop("Preset Options"),
 611         /* CUSTOM_OPTIONS */
 612         gettext_noop("Customized Options"),
 613         /* DEVELOPER_OPTIONS */
 614         gettext_noop("Developer Options"),
 615         /* help_config wants this array to be null-terminated */
 616         NULL
 617 };
 618
 619 /*
 620  * Displayable names for GUC variable types (enum config_type)
 621  *
 622  * Note: these strings are deliberately not localized.
 623  */
 624 const char *const config_type_names[] =
 625 {
 626          /* PGC_BOOL */ "bool",
 627          /* PGC_INT */ "integer",
 628          /* PGC_REAL */ "real",
 629          /* PGC_STRING */ "string",
 630          /* PGC_ENUM */ "enum"
 631 };
 632
 633
 634 /*
 635  * Contents of GUC tables
 636  *
 637  * See src/backend/utils/misc/README for design notes.
 638  *
 639  * TO ADD AN OPTION:
 640  *
 641  * 1. Declare a global variable of type bool, int, double, or char*
 642  *        and make use of it.
 643  *
 644  * 2. Decide at what times it's safe to set the option. See guc.h for
 645  *        details.
 646  *
 647  * 3. Decide on a name, a default value, upper and lower bounds (if
 648  *        applicable), etc.
 649  *
 650  * 4. Add a record below.
 651  *
 652  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 653  *        appropriate.
 654  *
 655  * 6. Don't forget to document the option (at least in config.sgml).
 656  *
 657  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 658  *        it is not single quoted at dump time.
 659  */
 660
 661
 662 /******** option records follow ********/
 663
 664 static struct config_bool ConfigureNamesBool[] =
 665 {
 666         {
 667                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 668                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 669                         NULL
 670                 },
 671                 &enable_seqscan,
 672                 true,
 673                 NULL, NULL, NULL
 674         },
 675         {
 676                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 677                         gettext_noop("Enables the planner's use of index-scan plans."),
 678                         NULL
 679                 },
 680                 &enable_indexscan,
 681                 true,
 682                 NULL, NULL, NULL
 683         },
 684         {
 685                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 686                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 687                         NULL
 688                 },
 689                 &enable_bitmapscan,
 690                 true,
 691                 NULL, NULL, NULL
 692         },
 693         {
 694                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 695                         gettext_noop("Enables the planner's use of TID scan plans."),
 696                         NULL
 697                 },
 698                 &enable_tidscan,
 699                 true,
 700                 NULL, NULL, NULL
 701         },
 702         {
 703                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 704                         gettext_noop("Enables the planner's use of explicit sort steps."),
 705                         NULL
 706                 },
 707                 &enable_sort,
 708                 true,
 709                 NULL, NULL, NULL
 710         },
 711         {
 712                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 713                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 714                         NULL
 715                 },
 716                 &enable_hashagg,
 717                 true,
 718                 NULL, NULL, NULL
 719         },
 720         {
 721                 {"enable_material", PGC_USERSET, QUERY_TUNING_METHOD,
 722                         gettext_noop("Enables the planner's use of materialization."),
 723                         NULL
 724                 },
 725                 &enable_material,
 726                 true,
 727                 NULL, NULL, NULL
 728         },
 729         {
 730                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 731                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 732                         NULL
 733                 },
 734                 &enable_nestloop,
 735                 true,
 736                 NULL, NULL, NULL
 737         },
 738         {
 739                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 740                         gettext_noop("Enables the planner's use of merge join plans."),
 741                         NULL
 742                 },
 743                 &enable_mergejoin,
 744                 true,
 745                 NULL, NULL, NULL
 746         },
 747         {
 748                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 749                         gettext_noop("Enables the planner's use of hash join plans."),
 750                         NULL
 751                 },
 752                 &enable_hashjoin,
 753                 true,
 754                 NULL, NULL, NULL
 755         },
 756         {
 757                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 758                         gettext_noop("Enables genetic query optimization."),
 759                         gettext_noop("This algorithm attempts to do planning without "
 760                                                  "exhaustive searching.")
 761                 },
 762                 &enable_geqo,
 763                 true,
 764                 NULL, NULL, NULL
 765         },
 766         {
 767                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 768                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 769                         gettext_noop("Shows whether the current user is a superuser."),
 770                         NULL,
 771                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 772                 },
 773                 &session_auth_is_superuser,
 774                 false,
 775                 NULL, NULL, NULL
 776         },
 777         {
 778                 {"bonjour", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
 779                         gettext_noop("Enables advertising the server via Bonjour."),
 780                         NULL
 781                 },
 782                 &enable_bonjour,
 783                 false,
 784                 check_bonjour, NULL, NULL
 785         },
 786         {
 787                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 788                         gettext_noop("Enables SSL connections."),
 789                         NULL
 790                 },
 791                 &EnableSSL,
 792                 false,
 793                 check_ssl, NULL, NULL
 794         },
 795         {
 796                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 797                         gettext_noop("Forces synchronization of updates to disk."),
 798                         gettext_noop("The server will use the fsync() system call in several places to make "
 799                         "sure that updates are physically written to disk. This insures "
 800                                                  "that a database cluster will recover to a consistent state after "
 801                                                  "an operating system or hardware crash.")
 802                 },
 803                 &enableFsync,
 804                 true,
 805                 NULL, NULL, NULL
 806         },
 807         {
 808                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 809                         gettext_noop("Continues processing past damaged page headers."),
 810                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 811                                 "report an error, aborting the current transaction. Setting "
 812                                                  "zero_damaged_pages to true causes the system to instead report a "
 813                                                  "warning, zero out the damaged page, and continue processing. This "
 814                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 815                         GUC_NOT_IN_SAMPLE
 816                 },
 817                 &zero_damaged_pages,
 818                 false,
 819                 NULL, NULL, NULL
 820         },
 821         {
 822                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 823                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 824                         gettext_noop("A page write in process during an operating system crash might be "
 825                                                  "only partially written to disk.  During recovery, the row changes "
 826                           "stored in WAL are not enough to recover.  This option writes "
 827                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 828                                                  "is possible.")
 829                 },
 830                 &fullPageWrites,
 831                 true,
 832                 NULL, NULL, NULL
 833         },
 834         {
 835                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 836                         gettext_noop("Logs each checkpoint."),
 837                         NULL
 838                 },
 839                 &log_checkpoints,
 840                 false,
 841                 NULL, NULL, NULL
 842         },
 843         {
 844                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 845                         gettext_noop("Logs each successful connection."),
 846                         NULL
 847                 },
 848                 &Log_connections,
 849                 false,
 850                 NULL, NULL, NULL
 851         },
 852         {
 853                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 854                         gettext_noop("Logs end of a session, including duration."),
 855                         NULL
 856                 },
 857                 &Log_disconnections,
 858                 false,
 859                 NULL, NULL, NULL
 860         },
 861         {
 862                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 863                         gettext_noop("Turns on various assertion checks."),
 864                         gettext_noop("This is a debugging aid."),
 865                         GUC_NOT_IN_SAMPLE
 866                 },
 867                 &assert_enabled,
 868 #ifdef USE_ASSERT_CHECKING
 869                 true,
 870 #else
 871                 false,
 872 #endif
 873                 check_debug_assertions, NULL, NULL
 874         },
 875
 876         {
 877                 {"exit_on_error", PGC_USERSET, ERROR_HANDLING_OPTIONS,
 878                         gettext_noop("Terminate session on any error."),
 879                         NULL
 880                 },
 881                 &ExitOnAnyError,
 882                 false,
 883                 NULL, NULL, NULL
 884         },
 885         {
 886                 {"restart_after_crash", PGC_SIGHUP, ERROR_HANDLING_OPTIONS,
 887                         gettext_noop("Reinitialize server after backend crash."),
 888                         NULL
 889                 },
 890                 &restart_after_crash,
 891                 true,
 892                 NULL, NULL, NULL
 893         },
 894
 895         {
 896                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 897                         gettext_noop("Logs the duration of each completed SQL statement."),
 898                         NULL
 899                 },
 900                 &log_duration,
 901                 false,
 902                 NULL, NULL, NULL
 903         },
 904         {
 905                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 906                         gettext_noop("Logs each query's parse tree."),
 907                         NULL
 908                 },
 909                 &Debug_print_parse,
 910                 false,
 911                 NULL, NULL, NULL
 912         },
 913         {
 914                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 915                         gettext_noop("Logs each query's rewritten parse tree."),
 916                         NULL
 917                 },
 918                 &Debug_print_rewritten,
 919                 false,
 920                 NULL, NULL, NULL
 921         },
 922         {
 923                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 924                         gettext_noop("Logs each query's execution plan."),
 925                         NULL
 926                 },
 927                 &Debug_print_plan,
 928                 false,
 929                 NULL, NULL, NULL
 930         },
 931         {
 932                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 933                         gettext_noop("Indents parse and plan tree displays."),
 934                         NULL
 935                 },
 936                 &Debug_pretty_print,
 937                 true,
 938                 NULL, NULL, NULL
 939         },
 940         {
 941                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 942                         gettext_noop("Writes parser performance statistics to the server log."),
 943                         NULL
 944                 },
 945                 &log_parser_stats,
 946                 false,
 947                 check_stage_log_stats, NULL, NULL
 948         },
 949         {
 950                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 951                         gettext_noop("Writes planner performance statistics to the server log."),
 952                         NULL
 953                 },
 954                 &log_planner_stats,
 955                 false,
 956                 check_stage_log_stats, NULL, NULL
 957         },
 958         {
 959                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 960                         gettext_noop("Writes executor performance statistics to the server log."),
 961                         NULL
 962                 },
 963                 &log_executor_stats,
 964                 false,
 965                 check_stage_log_stats, NULL, NULL
 966         },
 967         {
 968                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 969                         gettext_noop("Writes cumulative performance statistics to the server log."),
 970                         NULL
 971                 },
 972                 &log_statement_stats,
 973                 false,
 974                 check_log_stats, NULL, NULL
 975         },
 976 #ifdef BTREE_BUILD_STATS
 977         {
 978                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 979                         gettext_noop("No description available."),
 980                         NULL,
 981                         GUC_NOT_IN_SAMPLE
 982                 },
 983                 &log_btree_build_stats,
 984                 false,
 985                 NULL, NULL, NULL
 986         },
 987 #endif
 988
 989         {
 990                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 991                         gettext_noop("Collects information about executing commands."),
 992                         gettext_noop("Enables the collection of information on the currently "
 993                                                  "executing command of each session, along with "
 994                                                  "the time at which that command began execution.")
 995                 },
 996                 &pgstat_track_activities,
 997                 true,
 998                 NULL, NULL, NULL
 999         },
1000         {
1001                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
1002                         gettext_noop("Collects statistics on database activity."),
1003                         NULL
1004                 },
1005                 &pgstat_track_counts,
1006                 true,
1007                 NULL, NULL, NULL
1008         },
1009
1010         {
1011                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
1012                         gettext_noop("Updates the process title to show the active SQL command."),
1013                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
1014                 },
1015                 &update_process_title,
1016                 true,
1017                 NULL, NULL, NULL
1018         },
1019
1020         {
1021                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
1022                         gettext_noop("Starts the autovacuum subprocess."),
1023                         NULL
1024                 },
1025                 &autovacuum_start_daemon,
1026                 true,
1027                 NULL, NULL, NULL
1028         },
1029
1030         {
1031                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
1032                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
1033                         NULL,
1034                         GUC_NOT_IN_SAMPLE
1035                 },
1036                 &Trace_notify,
1037                 false,
1038                 NULL, NULL, NULL
1039         },
1040
1041 #ifdef LOCK_DEBUG
1042         {
1043                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
1044                         gettext_noop("No description available."),
1045                         NULL,
1046                         GUC_NOT_IN_SAMPLE
1047                 },
1048                 &Trace_locks,
1049                 false,
1050                 NULL, NULL, NULL
1051         },
1052         {
1053                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
1054                         gettext_noop("No description available."),
1055                         NULL,
1056                         GUC_NOT_IN_SAMPLE
1057                 },
1058                 &Trace_userlocks,
1059                 false,
1060                 NULL, NULL, NULL
1061         },
1062         {
1063                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
1064                         gettext_noop("No description available."),
1065                         NULL,
1066                         GUC_NOT_IN_SAMPLE
1067                 },
1068                 &Trace_lwlocks,
1069                 false,
1070                 NULL, NULL, NULL
1071         },
1072         {
1073                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
1074                         gettext_noop("No description available."),
1075                         NULL,
1076                         GUC_NOT_IN_SAMPLE
1077                 },
1078                 &Debug_deadlocks,
1079                 false,
1080                 NULL, NULL, NULL
1081         },
1082 #endif
1083
1084         {
1085                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
1086                         gettext_noop("Logs long lock waits."),
1087                         NULL
1088                 },
1089                 &log_lock_waits,
1090                 false,
1091                 NULL, NULL, NULL
1092         },
1093
1094         {
1095                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
1096                         gettext_noop("Logs the host name in the connection logs."),
1097                         gettext_noop("By default, connection logs only show the IP address "
1098                                                  "of the connecting host. If you want them to show the host name you "
1099                           "can turn this on, but depending on your host name resolution "
1100                            "setup it might impose a non-negligible performance penalty.")
1101                 },
1102                 &log_hostname,
1103                 false,
1104                 NULL, NULL, NULL
1105         },
1106         {
1107                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1108                         gettext_noop("Causes subtables to be included by default in various commands."),
1109                         NULL
1110                 },
1111                 &SQL_inheritance,
1112                 true,
1113                 NULL, NULL, NULL
1114         },
1115         {
1116                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
1117                         gettext_noop("Encrypt passwords."),
1118                         gettext_noop("When a password is specified in CREATE USER or "
1119                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
1120                                                  "this parameter determines whether the password is to be encrypted.")
1121                 },
1122                 &Password_encryption,
1123                 true,
1124                 NULL, NULL, NULL
1125         },
1126         {
1127                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
1128                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
1129                         gettext_noop("When turned on, expressions of the form expr = NULL "
1130                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
1131                                 "return true if expr evaluates to the null value, and false "
1132                            "otherwise. The correct behavior of expr = NULL is to always "
1133                                                  "return null (unknown).")
1134                 },
1135                 &Transform_null_equals,
1136                 false,
1137                 NULL, NULL, NULL
1138         },
1139         {
1140                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1141                         gettext_noop("Enables per-database user names."),
1142                         NULL
1143                 },
1144                 &Db_user_namespace,
1145                 false,
1146                 NULL, NULL, NULL
1147         },
1148         {
1149                 /* only here for backwards compatibility */
1150                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1151                         gettext_noop("This parameter doesn't do anything."),
1152                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1153                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1154                 },
1155                 &phony_autocommit,
1156                 true,
1157                 check_phony_autocommit, NULL, NULL
1158         },
1159         {
1160                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1161                         gettext_noop("Sets the default read-only status of new transactions."),
1162                         NULL
1163                 },
1164                 &DefaultXactReadOnly,
1165                 false,
1166                 NULL, NULL, NULL
1167         },
1168         {
1169                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1170                         gettext_noop("Sets the current transaction's read-only status."),
1171                         NULL,
1172                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1173                 },
1174                 &XactReadOnly,
1175                 false,
1176                 check_transaction_read_only, NULL, NULL
1177         },
1178         {
1179                 {"default_transaction_deferrable", PGC_USERSET, CLIENT_CONN_STATEMENT,
1180                         gettext_noop("Sets the default deferrable status of new transactions."),
1181                         NULL
1182                 },
1183                 &DefaultXactDeferrable,
1184                 false,
1185                 NULL, NULL, NULL
1186         },
1187         {
1188                 {"transaction_deferrable", PGC_USERSET, CLIENT_CONN_STATEMENT,
1189                         gettext_noop("Whether to defer a read-only serializable transaction until it can be executed with no possible serialization failures."),
1190                         NULL,
1191                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1192                 },
1193                 &XactDeferrable,
1194                 false,
1195                 check_transaction_deferrable, NULL, NULL
1196         },
1197         {
1198                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1199                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1200                         NULL
1201                 },
1202                 &check_function_bodies,
1203                 true,
1204                 NULL, NULL, NULL
1205         },
1206         {
1207                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1208                         gettext_noop("Enable input of NULL elements in arrays."),
1209                         gettext_noop("When turned on, unquoted NULL in an array input "
1210                                                  "value means a null value; "
1211                                                  "otherwise it is taken literally.")
1212                 },
1213                 &Array_nulls,
1214                 true,
1215                 NULL, NULL, NULL
1216         },
1217         {
1218                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1219                         gettext_noop("Create new tables with OIDs by default."),
1220                         NULL
1221                 },
1222                 &default_with_oids,
1223                 false,
1224                 NULL, NULL, NULL
1225         },
1226         {
1227                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1228                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1229                         NULL
1230                 },
1231                 &Logging_collector,
1232                 false,
1233                 NULL, NULL, NULL
1234         },
1235         {
1236                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1237                         gettext_noop("Truncate existing log files of same name during log rotation."),
1238                         NULL
1239                 },
1240                 &Log_truncate_on_rotation,
1241                 false,
1242                 NULL, NULL, NULL
1243         },
1244
1245 #ifdef TRACE_SORT
1246         {
1247                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1248                         gettext_noop("Emit information about resource usage in sorting."),
1249                         NULL,
1250                         GUC_NOT_IN_SAMPLE
1251                 },
1252                 &trace_sort,
1253                 false,
1254                 NULL, NULL, NULL
1255         },
1256 #endif
1257
1258 #ifdef TRACE_SYNCSCAN
1259         /* this is undocumented because not exposed in a standard build */
1260         {
1261                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1262                         gettext_noop("Generate debugging output for synchronized scanning."),
1263                         NULL,
1264                         GUC_NOT_IN_SAMPLE
1265                 },
1266                 &trace_syncscan,
1267                 false,
1268                 NULL, NULL, NULL
1269         },
1270 #endif
1271
1272 #ifdef DEBUG_BOUNDED_SORT
1273         /* this is undocumented because not exposed in a standard build */
1274         {
1275                 {
1276                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1277                         gettext_noop("Enable bounded sorting using heap sort."),
1278                         NULL,
1279                         GUC_NOT_IN_SAMPLE
1280                 },
1281                 &optimize_bounded_sort,
1282                 true,
1283                 NULL, NULL, NULL
1284         },
1285 #endif
1286
1287 #ifdef WAL_DEBUG
1288         {
1289                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1290                         gettext_noop("Emit WAL-related debugging output."),
1291                         NULL,
1292                         GUC_NOT_IN_SAMPLE
1293                 },
1294                 &XLOG_DEBUG,
1295                 false,
1296                 NULL, NULL, NULL
1297         },
1298 #endif
1299
1300         {
1301                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1302                         gettext_noop("Datetimes are integer based."),
1303                         NULL,
1304                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1305                 },
1306                 &integer_datetimes,
1307 #ifdef HAVE_INT64_TIMESTAMP
1308                 true,
1309 #else
1310                 false,
1311 #endif
1312                 NULL, NULL, NULL
1313         },
1314
1315         {
1316                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1317                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1318                         NULL
1319                 },
1320                 &pg_krb_caseins_users,
1321                 false,
1322                 NULL, NULL, NULL
1323         },
1324
1325         {
1326                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1327                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1328                         NULL
1329                 },
1330                 &escape_string_warning,
1331                 true,
1332                 NULL, NULL, NULL
1333         },
1334
1335         {
1336                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1337                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1338                         NULL,
1339                         GUC_REPORT
1340                 },
1341                 &standard_conforming_strings,
1342                 true,
1343                 NULL, NULL, NULL
1344         },
1345
1346         {
1347                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1348                         gettext_noop("Enable synchronized sequential scans."),
1349                         NULL
1350                 },
1351                 &synchronize_seqscans,
1352                 true,
1353                 NULL, NULL, NULL
1354         },
1355
1356         {
1357                 {"archive_mode", PGC_POSTMASTER, WAL_ARCHIVING,
1358                         gettext_noop("Allows archiving of WAL files using archive_command."),
1359                         NULL
1360                 },
1361                 &XLogArchiveMode,
1362                 false,
1363                 NULL, NULL, NULL
1364         },
1365
1366         {
1367                 {"hot_standby", PGC_POSTMASTER, REPLICATION_STANDBY,
1368                         gettext_noop("Allows connections and queries during recovery."),
1369                         NULL
1370                 },
1371                 &EnableHotStandby,
1372                 false,
1373                 NULL, NULL, NULL
1374         },
1375
1376         {
1377                 {"hot_standby_feedback", PGC_SIGHUP, REPLICATION_STANDBY,
1378                         gettext_noop("Allows feedback from a hot standby to the primary that will avoid query conflicts."),
1379                         NULL
1380                 },
1381                 &hot_standby_feedback,
1382                 false,
1383                 NULL, NULL, NULL
1384         },
1385
1386         {
1387                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1388                         gettext_noop("Allows modifications of the structure of system tables."),
1389                         NULL,
1390                         GUC_NOT_IN_SAMPLE
1391                 },
1392                 &allowSystemTableMods,
1393                 false,
1394                 NULL, NULL, NULL
1395         },
1396
1397         {
1398                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1399                         gettext_noop("Disables reading from system indexes."),
1400                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1401                                                  "to use.  The worst consequence is slowness."),
1402                         GUC_NOT_IN_SAMPLE
1403                 },
1404                 &IgnoreSystemIndexes,
1405                 false,
1406                 NULL, NULL, NULL
1407         },
1408
1409         {
1410                 {"lo_compat_privileges", PGC_SUSET, COMPAT_OPTIONS_PREVIOUS,
1411                         gettext_noop("Enables backward compatibility mode for privilege checks on large objects."),
1412                         gettext_noop("Skips privilege checks when reading or modifying large objects, "
1413                                   "for compatibility with PostgreSQL releases prior to 9.0.")
1414                 },
1415                 &lo_compat_privileges,
1416                 false,
1417                 NULL, NULL, NULL
1418         },
1419
1420         {
1421                 {"quote_all_identifiers", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1422                         gettext_noop("When generating SQL fragments, quote all identifiers."),
1423                         NULL,
1424                 },
1425                 &quote_all_identifiers,
1426                 false,
1427                 NULL, NULL, NULL
1428         },
1429
1430         /* End-of-list marker */
1431         {
1432                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL, NULL
1433         }
1434 };
1435
1436
1437 static struct config_int ConfigureNamesInt[] =
1438 {
1439         {
1440                 {"archive_timeout", PGC_SIGHUP, WAL_ARCHIVING,
1441                         gettext_noop("Forces a switch to the next xlog file if a "
1442                                                  "new file has not been started within N seconds."),
1443                         NULL,
1444                         GUC_UNIT_S
1445                 },
1446                 &XLogArchiveTimeout,
1447                 0, 0, INT_MAX,
1448                 NULL, NULL, NULL
1449         },
1450         {
1451                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1452                         gettext_noop("Waits N seconds on connection startup after authentication."),
1453                         gettext_noop("This allows attaching a debugger to the process."),
1454                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1455                 },
1456                 &PostAuthDelay,
1457                 0, 0, INT_MAX,
1458                 NULL, NULL, NULL
1459         },
1460         {
1461                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1462                         gettext_noop("Sets the default statistics target."),
1463                         gettext_noop("This applies to table columns that have not had a "
1464                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1465                 },
1466                 &default_statistics_target,
1467                 100, 1, 10000,
1468                 NULL, NULL, NULL
1469         },
1470         {
1471                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1472                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1473                                                  "are not collapsed."),
1474                         gettext_noop("The planner will merge subqueries into upper "
1475                                 "queries if the resulting FROM list would have no more than "
1476                                                  "this many items.")
1477                 },
1478                 &from_collapse_limit,
1479                 8, 1, INT_MAX,
1480                 NULL, NULL, NULL
1481         },
1482         {
1483                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1484                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1485                                                  "constructs are not flattened."),
1486                         gettext_noop("The planner will flatten explicit JOIN "
1487                                                  "constructs into lists of FROM items whenever a "
1488                                                  "list of no more than this many items would result.")
1489                 },
1490                 &join_collapse_limit,
1491                 8, 1, INT_MAX,
1492                 NULL, NULL, NULL
1493         },
1494         {
1495                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1496                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1497                         NULL
1498                 },
1499                 &geqo_threshold,
1500                 12, 2, INT_MAX,
1501                 NULL, NULL, NULL
1502         },
1503         {
1504                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1505                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1506                         NULL
1507                 },
1508                 &Geqo_effort,
1509                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT,
1510                 NULL, NULL, NULL
1511         },
1512         {
1513                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1514                         gettext_noop("GEQO: number of individuals in the population."),
1515                         gettext_noop("Zero selects a suitable default value.")
1516                 },
1517                 &Geqo_pool_size,
1518                 0, 0, INT_MAX,
1519                 NULL, NULL, NULL
1520         },
1521         {
1522                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1523                         gettext_noop("GEQO: number of iterations of the algorithm."),
1524                         gettext_noop("Zero selects a suitable default value.")
1525                 },
1526                 &Geqo_generations,
1527                 0, 0, INT_MAX,
1528                 NULL, NULL, NULL
1529         },
1530
1531         {
1532                 /* This is PGC_SUSET to prevent hiding from log_lock_waits. */
1533                 {"deadlock_timeout", PGC_SUSET, LOCK_MANAGEMENT,
1534                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1535                         NULL,
1536                         GUC_UNIT_MS
1537                 },
1538                 &DeadlockTimeout,
1539                 1000, 1, INT_MAX,
1540                 NULL, NULL, NULL
1541         },
1542
1543         {
1544                 {"max_standby_archive_delay", PGC_SIGHUP, REPLICATION_STANDBY,
1545                         gettext_noop("Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data."),
1546                         NULL,
1547                         GUC_UNIT_MS
1548                 },
1549                 &max_standby_archive_delay,
1550                 30 * 1000, -1, INT_MAX,
1551                 NULL, NULL, NULL
1552         },
1553
1554         {
1555                 {"max_standby_streaming_delay", PGC_SIGHUP, REPLICATION_STANDBY,
1556                         gettext_noop("Sets the maximum delay before canceling queries when a hot standby server is processing streamed WAL data."),
1557                         NULL,
1558                         GUC_UNIT_MS
1559                 },
1560                 &max_standby_streaming_delay,
1561                 30 * 1000, -1, INT_MAX,
1562                 NULL, NULL, NULL
1563         },
1564
1565         {
1566                 {"wal_receiver_status_interval", PGC_SIGHUP, REPLICATION_STANDBY,
1567                         gettext_noop("Sets the maximum interval between WAL receiver status reports to the primary."),
1568                         NULL,
1569                         GUC_UNIT_S
1570                 },
1571                 &wal_receiver_status_interval,
1572                 10, 0, INT_MAX / 1000,
1573                 NULL, NULL, NULL
1574         },
1575
1576         {
1577                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1578                         gettext_noop("Sets the maximum number of concurrent connections."),
1579                         NULL
1580                 },
1581                 &MaxConnections,
1582                 100, 1, MAX_BACKENDS,
1583                 check_maxconnections, assign_maxconnections, NULL
1584         },
1585
1586         {
1587                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1588                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1589                         NULL
1590                 },
1591                 &ReservedBackends,
1592                 3, 0, MAX_BACKENDS,
1593                 NULL, NULL, NULL
1594         },
1595
1596         /*
1597          * We sometimes multiply the number of shared buffers by two without
1598          * checking for overflow, so we mustn't allow more than INT_MAX / 2.
1599          */
1600         {
1601                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1602                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1603                         NULL,
1604                         GUC_UNIT_BLOCKS
1605                 },
1606                 &NBuffers,
1607                 1024, 16, INT_MAX / 2,
1608                 NULL, NULL, NULL
1609         },
1610
1611         {
1612                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1613                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1614                         NULL,
1615                         GUC_UNIT_BLOCKS
1616                 },
1617                 &num_temp_buffers,
1618                 1024, 100, INT_MAX / 2,
1619                 check_temp_buffers, NULL, NULL
1620         },
1621
1622         {
1623                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1624                         gettext_noop("Sets the TCP port the server listens on."),
1625                         NULL
1626                 },
1627                 &PostPortNumber,
1628                 DEF_PGPORT, 1, 65535,
1629                 NULL, NULL, NULL
1630         },
1631
1632         {
1633                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1634                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1635                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1636                                                  "permission set. The parameter value is expected "
1637                                                  "to be a numeric mode specification in the form "
1638                                                  "accepted by the chmod and umask system calls. "
1639                                                  "(To use the customary octal format the number must "
1640                                                  "start with a 0 (zero).)")
1641                 },
1642                 &Unix_socket_permissions,
1643                 0777, 0000, 0777,
1644                 NULL, NULL, show_unix_socket_permissions
1645         },
1646
1647         {
1648                 {"log_file_mode", PGC_SIGHUP, LOGGING_WHERE,
1649                         gettext_noop("Sets the file permissions for log files."),
1650                         gettext_noop("The parameter value is expected "
1651                                                  "to be a numeric mode specification in the form "
1652                                                  "accepted by the chmod and umask system calls. "
1653                                                  "(To use the customary octal format the number must "
1654                                                  "start with a 0 (zero).)")
1655                 },
1656                 &Log_file_mode,
1657                 0600, 0000, 0777,
1658                 NULL, NULL, show_log_file_mode
1659         },
1660
1661         {
1662                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1663                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1664                         gettext_noop("This much memory can be used by each internal "
1665                                                  "sort operation and hash table before switching to "
1666                                                  "temporary disk files."),
1667                         GUC_UNIT_KB
1668                 },
1669                 &work_mem,
1670                 1024, 64, MAX_KILOBYTES,
1671                 NULL, NULL, NULL
1672         },
1673
1674         {
1675                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1676                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1677                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1678                         GUC_UNIT_KB
1679                 },
1680                 &maintenance_work_mem,
1681                 16384, 1024, MAX_KILOBYTES,
1682                 NULL, NULL, NULL
1683         },
1684
1685         /*
1686          * We use the hopefully-safely-small value of 100kB as the compiled-in
1687          * default for max_stack_depth.  InitializeGUCOptions will increase it if
1688          * possible, depending on the actual platform-specific stack limit.
1689          */
1690         {
1691                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1692                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1693                         NULL,
1694                         GUC_UNIT_KB
1695                 },
1696                 &max_stack_depth,
1697                 100, 100, MAX_KILOBYTES,
1698                 check_max_stack_depth, assign_max_stack_depth, NULL
1699         },
1700
1701         {
1702                 {"temp_file_limit", PGC_SUSET, RESOURCES_DISK,
1703                         gettext_noop("Limits the total size of all temp files used by each session."),
1704                         gettext_noop("-1 means no limit."),
1705                         GUC_UNIT_KB
1706                 },
1707                 &temp_file_limit,
1708                 -1, -1, INT_MAX,
1709                 NULL, NULL, NULL
1710         },
1711
1712         {
1713                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES_VACUUM_DELAY,
1714                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1715                         NULL
1716                 },
1717                 &VacuumCostPageHit,
1718                 1, 0, 10000,
1719                 NULL, NULL, NULL
1720         },
1721
1722         {
1723                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES_VACUUM_DELAY,
1724                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1725                         NULL
1726                 },
1727                 &VacuumCostPageMiss,
1728                 10, 0, 10000,
1729                 NULL, NULL, NULL
1730         },
1731
1732         {
1733                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES_VACUUM_DELAY,
1734                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1735                         NULL
1736                 },
1737                 &VacuumCostPageDirty,
1738                 20, 0, 10000,
1739                 NULL, NULL, NULL
1740         },
1741
1742         {
1743                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES_VACUUM_DELAY,
1744                         gettext_noop("Vacuum cost amount available before napping."),
1745                         NULL
1746                 },
1747                 &VacuumCostLimit,
1748                 200, 1, 10000,
1749                 NULL, NULL, NULL
1750         },
1751
1752         {
1753                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES_VACUUM_DELAY,
1754                         gettext_noop("Vacuum cost delay in milliseconds."),
1755                         NULL,
1756                         GUC_UNIT_MS
1757                 },
1758                 &VacuumCostDelay,
1759                 0, 0, 100,
1760                 NULL, NULL, NULL
1761         },
1762
1763         {
1764                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1765                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1766                         NULL,
1767                         GUC_UNIT_MS
1768                 },
1769                 &autovacuum_vac_cost_delay,
1770                 20, -1, 100,
1771                 NULL, NULL, NULL
1772         },
1773
1774         {
1775                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1776                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1777                         NULL
1778                 },
1779                 &autovacuum_vac_cost_limit,
1780                 -1, -1, 10000,
1781                 NULL, NULL, NULL
1782         },
1783
1784         {
1785                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1786                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1787                         NULL
1788                 },
1789                 &max_files_per_process,
1790                 1000, 25, INT_MAX,
1791                 NULL, NULL, NULL
1792         },
1793
1794         /*
1795          * See also CheckRequiredParameterValues() if this parameter changes
1796          */
1797         {
1798                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES_MEM,
1799                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1800                         NULL
1801                 },
1802                 &max_prepared_xacts,
1803                 0, 0, MAX_BACKENDS,
1804                 NULL, NULL, NULL
1805         },
1806
1807 #ifdef LOCK_DEBUG
1808         {
1809                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1810                         gettext_noop("No description available."),
1811                         NULL,
1812                         GUC_NOT_IN_SAMPLE
1813                 },
1814                 &Trace_lock_oidmin,
1815                 FirstNormalObjectId, 0, INT_MAX,
1816                 NULL, NULL, NULL
1817         },
1818         {
1819                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1820                         gettext_noop("No description available."),
1821                         NULL,
1822                         GUC_NOT_IN_SAMPLE
1823                 },
1824                 &Trace_lock_table,
1825                 0, 0, INT_MAX,
1826                 NULL, NULL, NULL
1827         },
1828 #endif
1829
1830         {
1831                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1832                         gettext_noop("Sets the maximum allowed duration of any statement."),
1833                         gettext_noop("A value of 0 turns off the timeout."),
1834                         GUC_UNIT_MS
1835                 },
1836                 &StatementTimeout,
1837                 0, 0, INT_MAX,
1838                 NULL, NULL, NULL
1839         },
1840
1841         {
1842                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1843                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1844                         NULL
1845                 },
1846                 &vacuum_freeze_min_age,
1847                 50000000, 0, 1000000000,
1848                 NULL, NULL, NULL
1849         },
1850
1851         {
1852                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1853                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1854                         NULL
1855                 },
1856                 &vacuum_freeze_table_age,
1857                 150000000, 0, 2000000000,
1858                 NULL, NULL, NULL
1859         },
1860
1861         {
1862                 {"vacuum_defer_cleanup_age", PGC_SIGHUP, REPLICATION_MASTER,
1863                         gettext_noop("Number of transactions by which VACUUM and HOT cleanup should be deferred, if any."),
1864                         NULL
1865                 },
1866                 &vacuum_defer_cleanup_age,
1867                 0, 0, 1000000,
1868                 NULL, NULL, NULL
1869         },
1870
1871         /*
1872          * See also CheckRequiredParameterValues() if this parameter changes
1873          */
1874         {
1875                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1876                         gettext_noop("Sets the maximum number of locks per transaction."),
1877                         gettext_noop("The shared lock table is sized on the assumption that "
1878                           "at most max_locks_per_transaction * max_connections distinct "
1879                                                  "objects will need to be locked at any one time.")
1880                 },
1881                 &max_locks_per_xact,
1882                 64, 10, INT_MAX,
1883                 NULL, NULL, NULL
1884         },
1885
1886         {
1887                 {"max_pred_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1888                         gettext_noop("Sets the maximum number of predicate locks per transaction."),
1889                         gettext_noop("The shared predicate lock table is sized on the assumption that "
1890                                                  "at most max_pred_locks_per_transaction * max_connections distinct "
1891                                                  "objects will need to be locked at any one time.")
1892                 },
1893                 &max_predicate_locks_per_xact,
1894                 64, 10, INT_MAX,
1895                 NULL, NULL, NULL
1896         },
1897
1898         {
1899                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1900                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1901                         NULL,
1902                         GUC_UNIT_S
1903                 },
1904                 &AuthenticationTimeout,
1905                 60, 1, 600,
1906                 NULL, NULL, NULL
1907         },
1908
1909         {
1910                 /* Not for general use */
1911                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1912                         gettext_noop("Waits N seconds on connection startup before authentication."),
1913                         gettext_noop("This allows attaching a debugger to the process."),
1914                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1915                 },
1916                 &PreAuthDelay,
1917                 0, 0, 60,
1918                 NULL, NULL, NULL
1919         },
1920
1921         {
1922                 {"wal_keep_segments", PGC_SIGHUP, REPLICATION_SENDING,
1923                         gettext_noop("Sets the number of WAL files held for standby servers."),
1924                         NULL
1925                 },
1926                 &wal_keep_segments,
1927                 0, 0, INT_MAX,
1928                 NULL, NULL, NULL
1929         },
1930
1931         {
1932                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1933                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1934                         NULL
1935                 },
1936                 &CheckPointSegments,
1937                 3, 1, INT_MAX,
1938                 NULL, NULL, NULL
1939         },
1940
1941         {
1942                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1943                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1944                         NULL,
1945                         GUC_UNIT_S
1946                 },
1947                 &CheckPointTimeout,
1948                 300, 30, 3600,
1949                 NULL, NULL, NULL
1950         },
1951
1952         {
1953                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1954                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1955                                                  "frequently than this."),
1956                         gettext_noop("Write a message to the server log if checkpoints "
1957                         "caused by the filling of checkpoint segment files happens more "
1958                                                  "frequently than this number of seconds. Zero turns off the warning."),
1959                         GUC_UNIT_S
1960                 },
1961                 &CheckPointWarning,
1962                 30, 0, INT_MAX,
1963                 NULL, NULL, NULL
1964         },
1965
1966         {
1967                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1968                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1969                         NULL,
1970                         GUC_UNIT_XBLOCKS
1971                 },
1972                 &XLOGbuffers,
1973                 -1, -1, INT_MAX,
1974                 check_wal_buffers, NULL, NULL
1975         },
1976
1977         {
1978                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1979                         gettext_noop("WAL writer sleep time between WAL flushes."),
1980                         NULL,
1981                         GUC_UNIT_MS
1982                 },
1983                 &WalWriterDelay,
1984                 200, 1, 10000,
1985                 NULL, NULL, NULL
1986         },
1987
1988         {
1989                 /* see max_connections */
1990                 {"max_wal_senders", PGC_POSTMASTER, REPLICATION_SENDING,
1991                         gettext_noop("Sets the maximum number of simultaneously running WAL sender processes."),
1992                         NULL
1993                 },
1994                 &max_wal_senders,
1995                 0, 0, MAX_BACKENDS,
1996                 NULL, NULL, NULL
1997         },
1998
1999         {
2000                 {"replication_timeout", PGC_SIGHUP, REPLICATION_SENDING,
2001                         gettext_noop("Sets the maximum time to wait for WAL replication."),
2002                         NULL,
2003                         GUC_UNIT_MS
2004                 },
2005                 &replication_timeout,
2006                 60 * 1000, 0, INT_MAX,
2007                 NULL, NULL, NULL
2008         },
2009
2010         {
2011                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
2012                         gettext_noop("Sets the delay in microseconds between transaction commit and "
2013                                                  "flushing WAL to disk."),
2014                         NULL
2015                 },
2016                 &CommitDelay,
2017                 0, 0, 100000,
2018                 NULL, NULL, NULL
2019         },
2020
2021         {
2022                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
2023                         gettext_noop("Sets the minimum concurrent open transactions before performing "
2024                                                  "commit_delay."),
2025                         NULL
2026                 },
2027                 &CommitSiblings,
2028                 5, 0, 1000,
2029                 NULL, NULL, NULL
2030         },
2031
2032         {
2033                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
2034                         gettext_noop("Sets the number of digits displayed for floating-point values."),
2035                         gettext_noop("This affects real, double precision, and geometric data types. "
2036                          "The parameter value is added to the standard number of digits "
2037                                                  "(FLT_DIG or DBL_DIG as appropriate).")
2038                 },
2039                 &extra_float_digits,
2040                 0, -15, 3,
2041                 NULL, NULL, NULL
2042         },
2043
2044         {
2045                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
2046                         gettext_noop("Sets the minimum execution time above which "
2047                                                  "statements will be logged."),
2048                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
2049                         GUC_UNIT_MS
2050                 },
2051                 &log_min_duration_statement,
2052                 -1, -1, INT_MAX,
2053                 NULL, NULL, NULL
2054         },
2055
2056         {
2057                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
2058                         gettext_noop("Sets the minimum execution time above which "
2059                                                  "autovacuum actions will be logged."),
2060                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
2061                         GUC_UNIT_MS
2062                 },
2063                 &Log_autovacuum_min_duration,
2064                 -1, -1, INT_MAX,
2065                 NULL, NULL, NULL
2066         },
2067
2068         {
2069                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES_BGWRITER,
2070                         gettext_noop("Background writer sleep time between rounds."),
2071                         NULL,
2072                         GUC_UNIT_MS
2073                 },
2074                 &BgWriterDelay,
2075                 200, 10, 10000,
2076                 NULL, NULL, NULL
2077         },
2078
2079         {
2080                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES_BGWRITER,
2081                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
2082                         NULL
2083                 },
2084                 &bgwriter_lru_maxpages,
2085                 100, 0, 1000,
2086                 NULL, NULL, NULL
2087         },
2088
2089         {
2090                 {"effective_io_concurrency",
2091 #ifdef USE_PREFETCH
2092                         PGC_USERSET,
2093 #else
2094                         PGC_INTERNAL,
2095 #endif
2096                         RESOURCES_ASYNCHRONOUS,
2097                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
2098                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
2099                 },
2100                 &effective_io_concurrency,
2101 #ifdef USE_PREFETCH
2102                 1, 0, 1000,
2103 #else
2104                 0, 0, 0,
2105 #endif
2106                 check_effective_io_concurrency, assign_effective_io_concurrency, NULL
2107         },
2108
2109         {
2110                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
2111                         gettext_noop("Automatic log file rotation will occur after N minutes."),
2112                         NULL,
2113                         GUC_UNIT_MIN
2114                 },
2115                 &Log_RotationAge,
2116                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR,
2117                 NULL, NULL, NULL
2118         },
2119
2120         {
2121                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
2122                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
2123                         NULL,
2124                         GUC_UNIT_KB
2125                 },
2126                 &Log_RotationSize,
2127                 10 * 1024, 0, INT_MAX / 1024,
2128                 NULL, NULL, NULL
2129         },
2130
2131         {
2132                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
2133                         gettext_noop("Shows the maximum number of function arguments."),
2134                         NULL,
2135                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2136                 },
2137                 &max_function_args,
2138                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS,
2139                 NULL, NULL, NULL
2140         },
2141
2142         {
2143                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
2144                         gettext_noop("Shows the maximum number of index keys."),
2145                         NULL,
2146                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2147                 },
2148                 &max_index_keys,
2149                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS,
2150                 NULL, NULL, NULL
2151         },
2152
2153         {
2154                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
2155                         gettext_noop("Shows the maximum identifier length."),
2156                         NULL,
2157                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2158                 },
2159                 &max_identifier_length,
2160                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1,
2161                 NULL, NULL, NULL
2162         },
2163
2164         {
2165                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
2166                         gettext_noop("Shows the size of a disk block."),
2167                         NULL,
2168                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2169                 },
2170                 &block_size,
2171                 BLCKSZ, BLCKSZ, BLCKSZ,
2172                 NULL, NULL, NULL
2173         },
2174
2175         {
2176                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
2177                         gettext_noop("Shows the number of pages per disk file."),
2178                         NULL,
2179                         GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2180                 },
2181                 &segment_size,
2182                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE,
2183                 NULL, NULL, NULL
2184         },
2185
2186         {
2187                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
2188                         gettext_noop("Shows the block size in the write ahead log."),
2189                         NULL,
2190                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2191                 },
2192                 &wal_block_size,
2193                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ,
2194                 NULL, NULL, NULL
2195         },
2196
2197         {
2198                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
2199                         gettext_noop("Shows the number of pages per write ahead log segment."),
2200                         NULL,
2201                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2202                 },
2203                 &wal_segment_size,
2204                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
2205                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
2206                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
2207                 NULL, NULL, NULL
2208         },
2209
2210         {
2211                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
2212                         gettext_noop("Time to sleep between autovacuum runs."),
2213                         NULL,
2214                         GUC_UNIT_S
2215                 },
2216                 &autovacuum_naptime,
2217                 60, 1, INT_MAX / 1000,
2218                 NULL, NULL, NULL
2219         },
2220         {
2221                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
2222                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
2223                         NULL
2224                 },
2225                 &autovacuum_vac_thresh,
2226                 50, 0, INT_MAX,
2227                 NULL, NULL, NULL
2228         },
2229         {
2230                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
2231                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
2232                         NULL
2233                 },
2234                 &autovacuum_anl_thresh,
2235                 50, 0, INT_MAX,
2236                 NULL, NULL, NULL
2237         },
2238         {
2239                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
2240                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
2241                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
2242                         NULL
2243                 },
2244                 &autovacuum_freeze_max_age,
2245                 /* see pg_resetxlog if you change the upper-limit value */
2246                 200000000, 100000000, 2000000000,
2247                 NULL, NULL, NULL
2248         },
2249         {
2250                 /* see max_connections */
2251                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
2252                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
2253                         NULL
2254                 },
2255                 &autovacuum_max_workers,
2256                 3, 1, MAX_BACKENDS,
2257                 check_autovacuum_max_workers, assign_autovacuum_max_workers, NULL
2258         },
2259
2260         {
2261                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
2262                         gettext_noop("Time between issuing TCP keepalives."),
2263                         gettext_noop("A value of 0 uses the system default."),
2264                         GUC_UNIT_S
2265                 },
2266                 &tcp_keepalives_idle,
2267                 0, 0, INT_MAX,
2268                 NULL, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
2269         },
2270
2271         {
2272                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
2273                         gettext_noop("Time between TCP keepalive retransmits."),
2274                         gettext_noop("A value of 0 uses the system default."),
2275                         GUC_UNIT_S
2276                 },
2277                 &tcp_keepalives_interval,
2278                 0, 0, INT_MAX,
2279                 NULL, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
2280         },
2281
2282         {
2283                 {"ssl_renegotiation_limit", PGC_USERSET, CONN_AUTH_SECURITY,
2284                         gettext_noop("Set the amount of traffic to send and receive before renegotiating the encryption keys."),
2285                         NULL,
2286                         GUC_UNIT_KB,
2287                 },
2288                 &ssl_renegotiation_limit,
2289                 512 * 1024, 0, MAX_KILOBYTES,
2290                 NULL, NULL, NULL
2291         },
2292
2293         {
2294                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
2295                         gettext_noop("Maximum number of TCP keepalive retransmits."),
2296                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
2297                                                  "lost before a connection is considered dead. A value of 0 uses the "
2298                                                  "system default."),
2299                 },
2300                 &tcp_keepalives_count,
2301                 0, 0, INT_MAX,
2302                 NULL, assign_tcp_keepalives_count, show_tcp_keepalives_count
2303         },
2304
2305         {
2306                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
2307                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
2308                         NULL,
2309                         0
2310                 },
2311                 &GinFuzzySearchLimit,
2312                 0, 0, INT_MAX,
2313                 NULL, NULL, NULL
2314         },
2315
2316         {
2317                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
2318                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
2319                         gettext_noop("That is, the portion of the kernel's disk cache that "
2320                                                  "will be used for PostgreSQL data files. This is measured in disk "
2321                                                  "pages, which are normally 8 kB each."),
2322                         GUC_UNIT_BLOCKS,
2323                 },
2324                 &effective_cache_size,
2325                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX,
2326                 NULL, NULL, NULL
2327         },
2328
2329         {
2330                 /* Can't be set in postgresql.conf */
2331                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
2332                         gettext_noop("Shows the server version as an integer."),
2333                         NULL,
2334                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2335                 },
2336                 &server_version_num,
2337                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM,
2338                 NULL, NULL, NULL
2339         },
2340
2341         {
2342                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
2343                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
2344                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
2345                         GUC_UNIT_KB
2346                 },
2347                 &log_temp_files,
2348                 -1, -1, INT_MAX,
2349                 NULL, NULL, NULL
2350         },
2351
2352         {
2353                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
2354                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
2355                         NULL,
2356                 },
2357                 &pgstat_track_activity_query_size,
2358                 1024, 100, 102400,
2359                 NULL, NULL, NULL
2360         },
2361
2362         /* End-of-list marker */
2363         {
2364                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL, NULL
2365         }
2366 };
2367
2368
2369 static struct config_real ConfigureNamesReal[] =
2370 {
2371         {
2372                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
2373                         gettext_noop("Sets the planner's estimate of the cost of a "
2374                                                  "sequentially fetched disk page."),
2375                         NULL
2376                 },
2377                 &seq_page_cost,
2378                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX,
2379                 NULL, NULL, NULL
2380         },
2381         {
2382                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
2383                         gettext_noop("Sets the planner's estimate of the cost of a "
2384                                                  "nonsequentially fetched disk page."),
2385                         NULL
2386                 },
2387                 &random_page_cost,
2388                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX,
2389                 NULL, NULL, NULL
2390         },
2391         {
2392                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2393                         gettext_noop("Sets the planner's estimate of the cost of "
2394                                                  "processing each tuple (row)."),
2395                         NULL
2396                 },
2397                 &cpu_tuple_cost,
2398                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX,
2399                 NULL, NULL, NULL
2400         },
2401         {
2402                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2403                         gettext_noop("Sets the planner's estimate of the cost of "
2404                                                  "processing each index entry during an index scan."),
2405                         NULL
2406                 },
2407                 &cpu_index_tuple_cost,
2408                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX,
2409                 NULL, NULL, NULL
2410         },
2411         {
2412                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
2413                         gettext_noop("Sets the planner's estimate of the cost of "
2414                                                  "processing each operator or function call."),
2415                         NULL
2416                 },
2417                 &cpu_operator_cost,
2418                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX,
2419                 NULL, NULL, NULL
2420         },
2421
2422         {
2423                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2424                         gettext_noop("Sets the planner's estimate of the fraction of "
2425                                                  "a cursor's rows that will be retrieved."),
2426                         NULL
2427                 },
2428                 &cursor_tuple_fraction,
2429                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0,
2430                 NULL, NULL, NULL
2431         },
2432
2433         {
2434                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2435                         gettext_noop("GEQO: selective pressure within the population."),
2436                         NULL
2437                 },
2438                 &Geqo_selection_bias,
2439                 DEFAULT_GEQO_SELECTION_BIAS,
2440                 MIN_GEQO_SELECTION_BIAS, MAX_GEQO_SELECTION_BIAS,
2441                 NULL, NULL, NULL
2442         },
2443         {
2444                 {"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
2445                         gettext_noop("GEQO: seed for random path selection."),
2446                         NULL
2447                 },
2448                 &Geqo_seed,
2449                 0.0, 0.0, 1.0,
2450                 NULL, NULL, NULL
2451         },
2452
2453         {
2454                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES_BGWRITER,
2455                         gettext_noop("Multiple of the average buffer usage to free per round."),
2456                         NULL
2457                 },
2458                 &bgwriter_lru_multiplier,
2459                 2.0, 0.0, 10.0,
2460                 NULL, NULL, NULL
2461         },
2462
2463         {
2464                 {"seed", PGC_USERSET, UNGROUPED,
2465                         gettext_noop("Sets the seed for random-number generation."),
2466                         NULL,
2467                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2468                 },
2469                 &phony_random_seed,
2470                 0.0, -1.0, 1.0,
2471                 check_random_seed, assign_random_seed, show_random_seed
2472         },
2473
2474         {
2475                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2476                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2477                         NULL
2478                 },
2479                 &autovacuum_vac_scale,
2480                 0.2, 0.0, 100.0,
2481                 NULL, NULL, NULL
2482         },
2483         {
2484                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2485                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2486                         NULL
2487                 },
2488                 &autovacuum_anl_scale,
2489                 0.1, 0.0, 100.0,
2490                 NULL, NULL, NULL
2491         },
2492
2493         {
2494                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2495                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2496                         NULL
2497                 },
2498                 &CheckPointCompletionTarget,
2499                 0.5, 0.0, 1.0,
2500                 NULL, NULL, NULL
2501         },
2502
2503         /* End-of-list marker */
2504         {
2505                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL, NULL
2506         }
2507 };
2508
2509
2510 static struct config_string ConfigureNamesString[] =
2511 {
2512         {
2513                 {"archive_command", PGC_SIGHUP, WAL_ARCHIVING,
2514                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2515                         NULL
2516                 },
2517                 &XLogArchiveCommand,
2518                 "",
2519                 NULL, NULL, show_archive_command
2520         },
2521
2522         {
2523                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2524                         gettext_noop("Sets the client's character set encoding."),
2525                         NULL,
2526                         GUC_IS_NAME | GUC_REPORT
2527                 },
2528                 &client_encoding_string,
2529                 "SQL_ASCII",
2530                 check_client_encoding, assign_client_encoding, NULL
2531         },
2532
2533         {
2534                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2535                         gettext_noop("Controls information prefixed to each log line."),
2536                         gettext_noop("If blank, no prefix is used.")
2537                 },
2538                 &Log_line_prefix,
2539                 "",
2540                 NULL, NULL, NULL
2541         },
2542
2543         {
2544                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2545                         gettext_noop("Sets the time zone to use in log messages."),
2546                         NULL
2547                 },
2548                 &log_timezone_string,
2549                 "GMT",
2550                 check_log_timezone, assign_log_timezone, show_log_timezone
2551         },
2552
2553         {
2554                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2555                         gettext_noop("Sets the display format for date and time values."),
2556                         gettext_noop("Also controls interpretation of ambiguous "
2557                                                  "date inputs."),
2558                         GUC_LIST_INPUT | GUC_REPORT
2559                 },
2560                 &datestyle_string,
2561                 "ISO, MDY",
2562                 check_datestyle, assign_datestyle, NULL
2563         },
2564
2565         {
2566                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2567                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2568                         gettext_noop("An empty string selects the database's default tablespace."),
2569                         GUC_IS_NAME
2570                 },
2571                 &default_tablespace,
2572                 "",
2573                 check_default_tablespace, NULL, NULL
2574         },
2575
2576         {
2577                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2578                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2579                         NULL,
2580                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2581                 },
2582                 &temp_tablespaces,
2583                 "",
2584                 check_temp_tablespaces, assign_temp_tablespaces, NULL
2585         },
2586
2587         {
2588                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2589                         gettext_noop("Sets the path for dynamically loadable modules."),
2590                         gettext_noop("If a dynamically loadable module needs to be opened and "
2591                                                  "the specified name does not have a directory component (i.e., the "
2592                                                  "name does not contain a slash), the system will search this path for "
2593                                                  "the specified file."),
2594                         GUC_SUPERUSER_ONLY
2595                 },
2596                 &Dynamic_library_path,
2597                 "$libdir",
2598                 NULL, NULL, NULL
2599         },
2600
2601         {
2602                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2603                         gettext_noop("Sets the location of the Kerberos server key file."),
2604                         NULL,
2605                         GUC_SUPERUSER_ONLY
2606                 },
2607                 &pg_krb_server_keyfile,
2608                 PG_KRB_SRVTAB,
2609                 NULL, NULL, NULL
2610         },
2611
2612         {
2613                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2614                         gettext_noop("Sets the name of the Kerberos service."),
2615                         NULL
2616                 },
2617                 &pg_krb_srvnam,
2618                 PG_KRB_SRVNAM,
2619                 NULL, NULL, NULL
2620         },
2621
2622         {
2623                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2624                         gettext_noop("Sets the Bonjour service name."),
2625                         NULL
2626                 },
2627                 &bonjour_name,
2628                 "",
2629                 NULL, NULL, NULL
2630         },
2631
2632         /* See main.c about why defaults for LC_foo are not all alike */
2633
2634         {
2635                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2636                         gettext_noop("Shows the collation order locale."),
2637                         NULL,
2638                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2639                 },
2640                 &locale_collate,
2641                 "C",
2642                 NULL, NULL, NULL
2643         },
2644
2645         {
2646                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2647                         gettext_noop("Shows the character classification and case conversion locale."),
2648                         NULL,
2649                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2650                 },
2651                 &locale_ctype,
2652                 "C",
2653                 NULL, NULL, NULL
2654         },
2655
2656         {
2657                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2658                         gettext_noop("Sets the language in which messages are displayed."),
2659                         NULL
2660                 },
2661                 &locale_messages,
2662                 "",
2663                 check_locale_messages, assign_locale_messages, NULL
2664         },
2665
2666         {
2667                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2668                         gettext_noop("Sets the locale for formatting monetary amounts."),
2669                         NULL
2670                 },
2671                 &locale_monetary,
2672                 "C",
2673                 check_locale_monetary, assign_locale_monetary, NULL
2674         },
2675
2676         {
2677                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2678                         gettext_noop("Sets the locale for formatting numbers."),
2679                         NULL
2680                 },
2681                 &locale_numeric,
2682                 "C",
2683                 check_locale_numeric, assign_locale_numeric, NULL
2684         },
2685
2686         {
2687                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2688                         gettext_noop("Sets the locale for formatting date and time values."),
2689                         NULL
2690                 },
2691                 &locale_time,
2692                 "C",
2693                 check_locale_time, assign_locale_time, NULL
2694         },
2695
2696         {
2697                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2698                         gettext_noop("Lists shared libraries to preload into server."),
2699                         NULL,
2700                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2701                 },
2702                 &shared_preload_libraries_string,
2703                 "",
2704                 NULL, NULL, NULL
2705         },
2706
2707         {
2708                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2709                         gettext_noop("Lists shared libraries to preload into each backend."),
2710                         NULL,
2711                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2712                 },
2713                 &local_preload_libraries_string,
2714                 "",
2715                 NULL, NULL, NULL
2716         },
2717
2718         {
2719                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2720                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2721                         NULL,
2722                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2723                 },
2724                 &namespace_search_path,
2725                 "\"$user\",public",
2726                 check_search_path, assign_search_path, NULL
2727         },
2728
2729         {
2730                 /* Can't be set in postgresql.conf */
2731                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2732                         gettext_noop("Sets the server (database) character set encoding."),
2733                         NULL,
2734                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2735                 },
2736                 &server_encoding_string,
2737                 "SQL_ASCII",
2738                 NULL, NULL, NULL
2739         },
2740
2741         {
2742                 /* Can't be set in postgresql.conf */
2743                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2744                         gettext_noop("Shows the server version."),
2745                         NULL,
2746                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2747                 },
2748                 &server_version_string,
2749                 PG_VERSION,
2750                 NULL, NULL, NULL
2751         },
2752
2753         {
2754                 /* Not for general use --- used by SET ROLE */
2755                 {"role", PGC_USERSET, UNGROUPED,
2756                         gettext_noop("Sets the current role."),
2757                         NULL,
2758                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_NOT_WHILE_SEC_REST
2759                 },
2760                 &role_string,
2761                 "none",
2762                 check_role, assign_role, show_role
2763         },
2764
2765         {
2766                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2767                 {"session_authorization", PGC_USERSET, UNGROUPED,
2768                         gettext_noop("Sets the session user name."),
2769                         NULL,
2770                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_NOT_WHILE_SEC_REST
2771                 },
2772                 &session_authorization_string,
2773                 NULL,
2774                 check_session_authorization, assign_session_authorization, NULL
2775         },
2776
2777         {
2778                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2779                         gettext_noop("Sets the destination for server log output."),
2780                         gettext_noop("Valid values are combinations of \"stderr\", "
2781                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2782                                                  "depending on the platform."),
2783                         GUC_LIST_INPUT
2784                 },
2785                 &log_destination_string,
2786                 "stderr",
2787                 check_log_destination, assign_log_destination, NULL
2788         },
2789         {
2790                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2791                         gettext_noop("Sets the destination directory for log files."),
2792                         gettext_noop("Can be specified as relative to the data directory "
2793                                                  "or as absolute path."),
2794                         GUC_SUPERUSER_ONLY
2795                 },
2796                 &Log_directory,
2797                 "pg_log",
2798                 check_canonical_path, NULL, NULL
2799         },
2800         {
2801                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2802                         gettext_noop("Sets the file name pattern for log files."),
2803                         NULL,
2804                         GUC_SUPERUSER_ONLY
2805                 },
2806                 &Log_filename,
2807                 "postgresql-%Y-%m-%d_%H%M%S.log",
2808                 NULL, NULL, NULL
2809         },
2810
2811         {
2812                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2813                         gettext_noop("Sets the program name used to identify PostgreSQL "
2814                                                  "messages in syslog."),
2815                         NULL
2816                 },
2817                 &syslog_ident_str,
2818                 "postgres",
2819                 NULL, assign_syslog_ident, NULL
2820         },
2821
2822         {
2823                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2824                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2825                         NULL,
2826                         GUC_REPORT
2827                 },
2828                 &timezone_string,
2829                 "GMT",
2830                 check_timezone, assign_timezone, show_timezone
2831         },
2832         {
2833                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2834                         gettext_noop("Selects a file of time zone abbreviations."),
2835                         NULL
2836                 },
2837                 &timezone_abbreviations_string,
2838                 NULL,
2839                 check_timezone_abbreviations, assign_timezone_abbreviations, NULL
2840         },
2841
2842         {
2843                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2844                         gettext_noop("Sets the current transaction's isolation level."),
2845                         NULL,
2846                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2847                 },
2848                 &XactIsoLevel_string,
2849                 "default",
2850                 check_XactIsoLevel, assign_XactIsoLevel, show_XactIsoLevel
2851         },
2852
2853         {
2854                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2855                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2856                         gettext_noop("The owning user of the socket is always the user "
2857                                                  "that starts the server.")
2858                 },
2859                 &Unix_socket_group,
2860                 "",
2861                 NULL, NULL, NULL
2862         },
2863
2864         {
2865                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2866                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2867                         NULL,
2868                         GUC_SUPERUSER_ONLY
2869                 },
2870                 &UnixSocketDir,
2871                 "",
2872                 check_canonical_path, NULL, NULL
2873         },
2874
2875         {
2876                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2877                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2878                         NULL,
2879                         GUC_LIST_INPUT
2880                 },
2881                 &ListenAddresses,
2882                 "localhost",
2883                 NULL, NULL, NULL
2884         },
2885
2886         {
2887                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2888                         gettext_noop("Sets the server's data directory."),
2889                         NULL,
2890                         GUC_SUPERUSER_ONLY
2891                 },
2892                 &data_directory,
2893                 NULL,
2894                 NULL, NULL, NULL
2895         },
2896
2897         {
2898                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2899                         gettext_noop("Sets the server's main configuration file."),
2900                         NULL,
2901                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2902                 },
2903                 &ConfigFileName,
2904                 NULL,
2905                 NULL, NULL, NULL
2906         },
2907
2908         {
2909                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2910                         gettext_noop("Sets the server's \"hba\" configuration file."),
2911                         NULL,
2912                         GUC_SUPERUSER_ONLY
2913                 },
2914                 &HbaFileName,
2915                 NULL,
2916                 NULL, NULL, NULL
2917         },
2918
2919         {
2920                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2921                         gettext_noop("Sets the server's \"ident\" configuration file."),
2922                         NULL,
2923                         GUC_SUPERUSER_ONLY
2924                 },
2925                 &IdentFileName,
2926                 NULL,
2927                 NULL, NULL, NULL
2928         },
2929
2930         {
2931                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2932                         gettext_noop("Writes the postmaster PID to the specified file."),
2933                         NULL,
2934                         GUC_SUPERUSER_ONLY
2935                 },
2936                 &external_pid_file,
2937                 NULL,
2938                 check_canonical_path, NULL, NULL
2939         },
2940
2941         {
2942                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2943                         gettext_noop("Writes temporary statistics files to the specified directory."),
2944                         NULL,
2945                         GUC_SUPERUSER_ONLY
2946                 },
2947                 &pgstat_temp_directory,
2948                 "pg_stat_tmp",
2949                 check_canonical_path, assign_pgstat_temp_directory, NULL
2950         },
2951
2952         {
2953                 {"synchronous_standby_names", PGC_SIGHUP, REPLICATION_MASTER,
2954                         gettext_noop("List of names of potential synchronous standbys."),
2955                         NULL,
2956                         GUC_LIST_INPUT
2957                 },
2958                 &SyncRepStandbyNames,
2959                 "",
2960                 check_synchronous_standby_names, NULL, NULL
2961         },
2962
2963         {
2964                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2965                         gettext_noop("Sets default text search configuration."),
2966                         NULL
2967                 },
2968                 &TSCurrentConfig,
2969                 "pg_catalog.simple",
2970                 check_TSCurrentConfig, assign_TSCurrentConfig, NULL
2971         },
2972
2973         {
2974                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2975                         gettext_noop("Sets the list of allowed SSL ciphers."),
2976                         NULL,
2977                         GUC_SUPERUSER_ONLY
2978                 },
2979                 &SSLCipherSuites,
2980 #ifdef USE_SSL
2981                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH",
2982 #else
2983                 "none",
2984 #endif
2985                 NULL, NULL, NULL
2986         },
2987
2988         {
2989                 {"application_name", PGC_USERSET, LOGGING_WHAT,
2990                         gettext_noop("Sets the application name to be reported in statistics and logs."),
2991                         NULL,
2992                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE
2993                 },
2994                 &application_name,
2995                 "",
2996                 check_application_name, assign_application_name, NULL
2997         },
2998
2999         /* End-of-list marker */
3000         {
3001                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL, NULL
3002         }
3003 };
3004
3005
3006 static struct config_enum ConfigureNamesEnum[] =
3007 {
3008         {
3009                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
3010                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
3011                         NULL
3012                 },
3013                 &backslash_quote,
3014                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options,
3015                 NULL, NULL, NULL
3016         },
3017
3018         {
3019                 {"bytea_output", PGC_USERSET, CLIENT_CONN_STATEMENT,
3020                         gettext_noop("Sets the output format for bytea."),
3021                         NULL
3022                 },
3023                 &bytea_output,
3024                 BYTEA_OUTPUT_HEX, bytea_output_options,
3025                 NULL, NULL, NULL
3026         },
3027
3028         {
3029                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
3030                         gettext_noop("Sets the message levels that are sent to the client."),
3031                         gettext_noop("Each level includes all the levels that follow it. The later"
3032                                                  " the level, the fewer messages are sent.")
3033                 },
3034                 &client_min_messages,
3035                 NOTICE, client_message_level_options,
3036                 NULL, NULL, NULL
3037         },
3038
3039         {
3040                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
3041                         gettext_noop("Enables the planner to use constraints to optimize queries."),
3042                         gettext_noop("Table scans will be skipped if their constraints"
3043                                                  " guarantee that no rows match the query.")
3044                 },
3045                 &constraint_exclusion,
3046                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
3047                 NULL, NULL, NULL
3048         },
3049
3050         {
3051                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
3052                         gettext_noop("Sets the transaction isolation level of each new transaction."),
3053                         NULL
3054                 },
3055                 &DefaultXactIsoLevel,
3056                 XACT_READ_COMMITTED, isolation_level_options,
3057                 NULL, NULL, NULL
3058         },
3059
3060         {
3061                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
3062                         gettext_noop("Sets the display format for interval values."),
3063                         NULL,
3064                         GUC_REPORT
3065                 },
3066                 &IntervalStyle,
3067                 INTSTYLE_POSTGRES, intervalstyle_options,
3068                 NULL, NULL, NULL
3069         },
3070
3071         {
3072                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHAT,
3073                         gettext_noop("Sets the verbosity of logged messages."),
3074                         NULL
3075                 },
3076                 &Log_error_verbosity,
3077                 PGERROR_DEFAULT, log_error_verbosity_options,
3078                 NULL, NULL, NULL
3079         },
3080
3081         {
3082                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
3083                         gettext_noop("Sets the message levels that are logged."),
3084                         gettext_noop("Each level includes all the levels that follow it. The later"
3085                                                  " the level, the fewer messages are sent.")
3086                 },
3087                 &log_min_messages,
3088                 WARNING, server_message_level_options,
3089                 NULL, NULL, NULL
3090         },
3091
3092         {
3093                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
3094                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
3095                         gettext_noop("Each level includes all the levels that follow it. The later"
3096                                                  " the level, the fewer messages are sent.")
3097                 },
3098                 &log_min_error_statement,
3099                 ERROR, server_message_level_options,
3100                 NULL, NULL, NULL
3101         },
3102
3103         {
3104                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
3105                         gettext_noop("Sets the type of statements logged."),
3106                         NULL
3107                 },
3108                 &log_statement,
3109                 LOGSTMT_NONE, log_statement_options,
3110                 NULL, NULL, NULL
3111         },
3112
3113         {
3114                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
3115                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
3116                         NULL
3117                 },
3118                 &syslog_facility,
3119 #ifdef HAVE_SYSLOG
3120                 LOG_LOCAL0,
3121 #else
3122                 0,
3123 #endif
3124                 syslog_facility_options,
3125                 NULL, assign_syslog_facility, NULL
3126         },
3127
3128         {
3129                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
3130                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
3131                         NULL
3132                 },
3133                 &SessionReplicationRole,
3134                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
3135                 NULL, assign_session_replication_role, NULL
3136         },
3137
3138         {
3139                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
3140                         gettext_noop("Sets the current transaction's synchronization level."),
3141                         NULL
3142                 },
3143                 &synchronous_commit,
3144                 SYNCHRONOUS_COMMIT_ON, synchronous_commit_options,
3145                 NULL, NULL, NULL
3146         },
3147
3148         {
3149                 {"trace_recovery_messages", PGC_SIGHUP, DEVELOPER_OPTIONS,
3150                         gettext_noop("Enables logging of recovery-related debugging information."),
3151                         gettext_noop("Each level includes all the levels that follow it. The later"
3152                                                  " the level, the fewer messages are sent.")
3153                 },
3154                 &trace_recovery_messages,
3155
3156                 /*
3157                  * client_message_level_options allows too many values, really, but
3158                  * it's not worth having a separate options array for this.
3159                  */
3160                 LOG, client_message_level_options,
3161                 NULL, NULL, NULL
3162         },
3163
3164         {
3165                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
3166                         gettext_noop("Collects function-level statistics on database activity."),
3167                         NULL
3168                 },
3169                 &pgstat_track_functions,
3170                 TRACK_FUNC_OFF, track_function_options,
3171                 NULL, NULL, NULL
3172         },
3173
3174         {
3175                 {"wal_level", PGC_POSTMASTER, WAL_SETTINGS,
3176                         gettext_noop("Set the level of information written to the WAL."),
3177                         NULL
3178                 },
3179                 &wal_level,
3180                 WAL_LEVEL_MINIMAL, wal_level_options,
3181                 NULL, NULL, NULL
3182         },
3183
3184         {
3185                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
3186                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
3187                         NULL
3188                 },
3189                 &sync_method,
3190                 DEFAULT_SYNC_METHOD, sync_method_options,
3191                 NULL, assign_xlog_sync_method, NULL
3192         },
3193
3194         {
3195                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
3196                         gettext_noop("Sets how binary values are to be encoded in XML."),
3197                         NULL
3198                 },
3199                 &xmlbinary,
3200                 XMLBINARY_BASE64, xmlbinary_options,
3201                 NULL, NULL, NULL
3202         },
3203
3204         {
3205                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
3206                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
3207                                                  "operations is to be considered as documents or content fragments."),
3208                         NULL
3209                 },
3210                 &xmloption,
3211                 XMLOPTION_CONTENT, xmloption_options,
3212                 NULL, NULL, NULL
3213         },
3214
3215
3216         /* End-of-list marker */
3217         {
3218                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL, NULL
3219         }
3220 };
3221
3222 /******** end of options list ********/
3223
3224
3225 /*
3226  * To allow continued support of obsolete names for GUC variables, we apply
3227  * the following mappings to any unrecognized name.  Note that an old name
3228  * should be mapped to a new one only if the new variable has very similar
3229  * semantics to the old.
3230  */
3231 static const char *const map_old_guc_names[] = {
3232         "sort_mem", "work_mem",
3233         "vacuum_mem", "maintenance_work_mem",
3234         NULL
3235 };
3236
3237
3238 /*
3239  * Actual lookup of variables is done through this single, sorted array.
3240  */
3241 static struct config_generic **guc_variables;
3242
3243 /* Current number of variables contained in the vector */
3244 static int      num_guc_variables;
3245
3246 /* Vector capacity */
3247 static int      size_guc_variables;
3248
3249
3250 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
3251
3252 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
3253
3254 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
3255
3256
3257 static int      guc_var_compare(const void *a, const void *b);
3258 static int      guc_name_compare(const char *namea, const char *nameb);
3259 static void InitializeGUCOptionsFromEnvironment(void);
3260 static void InitializeOneGUCOption(struct config_generic * gconf);
3261 static void push_old_value(struct config_generic * gconf, GucAction action);
3262 static void ReportGUCOption(struct config_generic * record);
3263 static void reapply_stacked_values(struct config_generic * variable,
3264                                            struct config_string *pHolder,
3265                                            GucStack *stack,
3266                                            const char *curvalue,
3267                                            GucContext curscontext, GucSource cursource);
3268 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
3269 static void ShowAllGUCConfig(DestReceiver *dest);
3270 static char *_ShowOption(struct config_generic * record, bool use_units);
3271 static bool validate_option_array_item(const char *name, const char *value,
3272                                                    bool skipIfNoPermissions);
3273
3274
3275 /*
3276  * Some infrastructure for checking malloc/strdup/realloc calls
3277  */
3278 static void *
3279 guc_malloc(int elevel, size_t size)
3280 {
3281         void       *data;
3282
3283         data = malloc(size);
3284         if (data == NULL)
3285                 ereport(elevel,
3286                                 (errcode(ERRCODE_OUT_OF_MEMORY),
3287                                  errmsg("out of memory")));
3288         return data;
3289 }
3290
3291 static void *
3292 guc_realloc(int elevel, void *old, size_t size)
3293 {
3294         void       *data;
3295
3296         data = realloc(old, size);
3297         if (data == NULL)
3298                 ereport(elevel,
3299                                 (errcode(ERRCODE_OUT_OF_MEMORY),
3300                                  errmsg("out of memory")));
3301         return data;
3302 }
3303
3304 static char *
3305 guc_strdup(int elevel, const char *src)
3306 {
3307         char       *data;
3308
3309         data = strdup(src);
3310         if (data == NULL)
3311                 ereport(elevel,
3312                                 (errcode(ERRCODE_OUT_OF_MEMORY),
3313                                  errmsg("out of memory")));
3314         return data;
3315 }
3316
3317
3318 /*
3319  * Detect whether strval is referenced anywhere in a GUC string item
3320  */
3321 static bool
3322 string_field_used(struct config_string * conf, char *strval)
3323 {
3324         GucStack   *stack;
3325
3326         if (strval == *(conf->variable) ||
3327                 strval == conf->reset_val ||
3328                 strval == conf->boot_val)
3329                 return true;
3330         for (stack = conf->gen.stack; stack; stack = stack->prev)
3331         {
3332                 if (strval == stack->prior.val.stringval ||
3333                         strval == stack->masked.val.stringval)
3334                         return true;
3335         }
3336         return false;
3337 }
3338
3339 /*
3340  * Support for assigning to a field of a string GUC item.  Free the prior
3341  * value if it's not referenced anywhere else in the item (including stacked
3342  * states).
3343  */
3344 static void
3345 set_string_field(struct config_string * conf, char **field, char *newval)
3346 {
3347         char       *oldval = *field;
3348
3349         /* Do the assignment */
3350         *field = newval;
3351
3352         /* Free old value if it's not NULL and isn't referenced anymore */
3353         if (oldval && !string_field_used(conf, oldval))
3354                 free(oldval);
3355 }
3356
3357 /*
3358  * Detect whether an "extra" struct is referenced anywhere in a GUC item
3359  */
3360 static bool
3361 extra_field_used(struct config_generic * gconf, void *extra)
3362 {
3363         GucStack   *stack;
3364
3365         if (extra == gconf->extra)
3366                 return true;
3367         switch (gconf->vartype)
3368         {
3369                 case PGC_BOOL:
3370                         if (extra == ((struct config_bool *) gconf)->reset_extra)
3371                                 return true;
3372                         break;
3373                 case PGC_INT:
3374                         if (extra == ((struct config_int *) gconf)->reset_extra)
3375                                 return true;
3376                         break;
3377                 case PGC_REAL:
3378                         if (extra == ((struct config_real *) gconf)->reset_extra)
3379                                 return true;
3380                         break;
3381                 case PGC_STRING:
3382                         if (extra == ((struct config_string *) gconf)->reset_extra)
3383                                 return true;
3384                         break;
3385                 case PGC_ENUM:
3386                         if (extra == ((struct config_enum *) gconf)->reset_extra)
3387                                 return true;
3388                         break;
3389         }
3390         for (stack = gconf->stack; stack; stack = stack->prev)
3391         {
3392                 if (extra == stack->prior.extra ||
3393                         extra == stack->masked.extra)
3394                         return true;
3395         }
3396
3397         return false;
3398 }
3399
3400 /*
3401  * Support for assigning to an "extra" field of a GUC item.  Free the prior
3402  * value if it's not referenced anywhere else in the item (including stacked
3403  * states).
3404  */
3405 static void
3406 set_extra_field(struct config_generic * gconf, void **field, void *newval)
3407 {
3408         void       *oldval = *field;
3409
3410         /* Do the assignment */
3411         *field = newval;
3412
3413         /* Free old value if it's not NULL and isn't referenced anymore */
3414         if (oldval && !extra_field_used(gconf, oldval))
3415                 free(oldval);
3416 }
3417
3418 /*
3419  * Support for copying a variable's active value into a stack entry.
3420  * The "extra" field associated with the active value is copied, too.
3421  *
3422  * NB: be sure stringval and extra fields of a new stack entry are
3423  * initialized to NULL before this is used, else we'll try to free() them.
3424  */
3425 static void
3426 set_stack_value(struct config_generic * gconf, config_var_value *val)
3427 {
3428         switch (gconf->vartype)
3429         {
3430                 case PGC_BOOL:
3431                         val->val.boolval =
3432                                 *((struct config_bool *) gconf)->variable;
3433                         break;
3434                 case PGC_INT:
3435                         val->val.intval =
3436                                 *((struct config_int *) gconf)->variable;
3437                         break;
3438                 case PGC_REAL:
3439                         val->val.realval =
3440                                 *((struct config_real *) gconf)->variable;
3441                         break;
3442                 case PGC_STRING:
3443                         set_string_field((struct config_string *) gconf,
3444                                                          &(val->val.stringval),
3445                                                          *((struct config_string *) gconf)->variable);
3446                         break;
3447                 case PGC_ENUM:
3448                         val->val.enumval =
3449                                 *((struct config_enum *) gconf)->variable;
3450                         break;
3451         }
3452         set_extra_field(gconf, &(val->extra), gconf->extra);
3453 }
3454
3455 /*
3456  * Support for discarding a no-longer-needed value in a stack entry.
3457  * The "extra" field associated with the stack entry is cleared, too.
3458  */
3459 static void
3460 discard_stack_value(struct config_generic * gconf, config_var_value *val)
3461 {
3462         switch (gconf->vartype)
3463         {
3464                 case PGC_BOOL:
3465                 case PGC_INT:
3466                 case PGC_REAL:
3467                 case PGC_ENUM:
3468                         /* no need to do anything */
3469                         break;
3470                 case PGC_STRING:
3471                         set_string_field((struct config_string *) gconf,
3472                                                          &(val->val.stringval),
3473                                                          NULL);
3474                         break;
3475         }
3476         set_extra_field(gconf, &(val->extra), NULL);
3477 }
3478
3479
3480 /*
3481  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
3482  */
3483 struct config_generic **
3484 get_guc_variables(void)
3485 {
3486         return guc_variables;
3487 }
3488
3489
3490 /*
3491  * Build the sorted array.      This is split out so that it could be
3492  * re-executed after startup (eg, we could allow loadable modules to
3493  * add vars, and then we'd need to re-sort).
3494  */
3495 void
3496 build_guc_variables(void)
3497 {
3498         int                     size_vars;
3499         int                     num_vars = 0;
3500         struct config_generic **guc_vars;
3501         int                     i;
3502
3503         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
3504         {
3505                 struct config_bool *conf = &ConfigureNamesBool[i];
3506
3507                 /* Rather than requiring vartype to be filled in by hand, do this: */
3508                 conf->gen.vartype = PGC_BOOL;
3509                 num_vars++;
3510         }
3511
3512         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
3513         {
3514                 struct config_int *conf = &ConfigureNamesInt[i];
3515
3516                 conf->gen.vartype = PGC_INT;
3517                 num_vars++;
3518         }
3519
3520         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
3521         {
3522                 struct config_real *conf = &ConfigureNamesReal[i];
3523
3524                 conf->gen.vartype = PGC_REAL;
3525                 num_vars++;
3526         }
3527
3528         for (i = 0; ConfigureNamesString[i].gen.name; i++)
3529         {
3530                 struct config_string *conf = &ConfigureNamesString[i];
3531
3532                 conf->gen.vartype = PGC_STRING;
3533                 num_vars++;
3534         }
3535
3536         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
3537         {
3538                 struct config_enum *conf = &ConfigureNamesEnum[i];
3539
3540                 conf->gen.vartype = PGC_ENUM;
3541                 num_vars++;
3542         }
3543
3544         /*
3545          * Create table with 20% slack
3546          */
3547         size_vars = num_vars + num_vars / 4;
3548
3549         guc_vars = (struct config_generic **)
3550                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
3551
3552         num_vars = 0;
3553
3554         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
3555                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
3556
3557         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
3558                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
3559
3560         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
3561                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
3562
3563         for (i = 0; ConfigureNamesString[i].gen.name; i++)
3564                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
3565
3566         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
3567                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
3568
3569         if (guc_variables)
3570                 free(guc_variables);
3571         guc_variables = guc_vars;
3572         num_guc_variables = num_vars;
3573         size_guc_variables = size_vars;
3574         qsort((void *) guc_variables, num_guc_variables,
3575                   sizeof(struct config_generic *), guc_var_compare);
3576 }
3577
3578 /*
3579  * Add a new GUC variable to the list of known variables. The
3580  * list is expanded if needed.
3581  */
3582 static bool
3583 add_guc_variable(struct config_generic * var, int elevel)
3584 {
3585         if (num_guc_variables + 1 >= size_guc_variables)
3586         {
3587                 /*
3588                  * Increase the vector by 25%
3589                  */
3590                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
3591                 struct config_generic **guc_vars;
3592
3593                 if (size_vars == 0)
3594                 {
3595                         size_vars = 100;
3596                         guc_vars = (struct config_generic **)
3597                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3598                 }
3599                 else
3600                 {
3601                         guc_vars = (struct config_generic **)
3602                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3603                 }
3604
3605                 if (guc_vars == NULL)
3606                         return false;           /* out of memory */
3607
3608                 guc_variables = guc_vars;
3609                 size_guc_variables = size_vars;
3610         }
3611         guc_variables[num_guc_variables++] = var;
3612         qsort((void *) guc_variables, num_guc_variables,
3613                   sizeof(struct config_generic *), guc_var_compare);
3614         return true;
3615 }
3616
3617 /*
3618  * Create and add a placeholder variable for a custom variable name.
3619  */
3620 static struct config_generic *
3621 add_placeholder_variable(const char *name, int elevel)
3622 {
3623         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3624         struct config_string *var;
3625         struct config_generic *gen;
3626
3627         var = (struct config_string *) guc_malloc(elevel, sz);
3628         if (var == NULL)
3629                 return NULL;
3630         memset(var, 0, sz);
3631         gen = &var->gen;
3632
3633         gen->name = guc_strdup(elevel, name);
3634         if (gen->name == NULL)
3635         {
3636                 free(var);
3637                 return NULL;
3638         }
3639
3640         gen->context = PGC_USERSET;
3641         gen->group = CUSTOM_OPTIONS;
3642         gen->short_desc = "GUC placeholder variable";
3643         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3644         gen->vartype = PGC_STRING;
3645
3646         /*
3647          * The char* is allocated at the end of the struct since we have no
3648          * 'static' place to point to.  Note that the current value, as well as
3649          * the boot and reset values, start out NULL.
3650          */
3651         var->variable = (char **) (var + 1);
3652
3653         if (!add_guc_variable((struct config_generic *) var, elevel))
3654         {
3655                 free((void *) gen->name);
3656                 free(var);
3657                 return NULL;
3658         }
3659
3660         return gen;
3661 }
3662
3663 /*
3664  * Look up option NAME.  If it exists, return a pointer to its record,
3665  * else return NULL.  If create_placeholders is TRUE, we'll create a
3666  * placeholder record for a valid-looking custom variable name.
3667  */
3668 static struct config_generic *
3669 find_option(const char *name, bool create_placeholders, int elevel)
3670 {
3671         const char **key = &name;
3672         struct config_generic **res;
3673         int                     i;
3674
3675         Assert(name);
3676
3677         /*
3678          * By equating const char ** with struct config_generic *, we are assuming
3679          * the name field is first in config_generic.
3680          */
3681         res = (struct config_generic **) bsearch((void *) &key,
3682                                                                                          (void *) guc_variables,
3683                                                                                          num_guc_variables,
3684                                                                                          sizeof(struct config_generic *),
3685                                                                                          guc_var_compare);
3686         if (res)
3687                 return *res;
3688
3689         /*
3690          * See if the name is an obsolete name for a variable.  We assume that the
3691          * set of supported old names is short enough that a brute-force search is
3692          * the best way.
3693          */
3694         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3695         {
3696                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3697                         return find_option(map_old_guc_names[i + 1], false, elevel);
3698         }
3699
3700         if (create_placeholders)
3701         {
3702                 /*
3703                  * Check if the name is qualified, and if so, add a placeholder.
3704                  */
3705                 if (strchr(name, GUC_QUALIFIER_SEPARATOR) != NULL)
3706                         return add_placeholder_variable(name, elevel);
3707         }
3708
3709         /* Unknown name */
3710         return NULL;
3711 }
3712
3713
3714 /*
3715  * comparator for qsorting and bsearching guc_variables array
3716  */
3717 static int
3718 guc_var_compare(const void *a, const void *b)
3719 {
3720         struct config_generic *confa = *(struct config_generic **) a;
3721         struct config_generic *confb = *(struct config_generic **) b;
3722
3723         return guc_name_compare(confa->name, confb->name);
3724 }
3725
3726 /*
3727  * the bare comparison function for GUC names
3728  */
3729 static int
3730 guc_name_compare(const char *namea, const char *nameb)
3731 {
3732         /*
3733          * The temptation to use strcasecmp() here must be resisted, because the
3734          * array ordering has to remain stable across setlocale() calls. So, build
3735          * our own with a simple ASCII-only downcasing.
3736          */
3737         while (*namea && *nameb)
3738         {
3739                 char            cha = *namea++;
3740                 char            chb = *nameb++;
3741
3742                 if (cha >= 'A' && cha <= 'Z')
3743                         cha += 'a' - 'A';
3744                 if (chb >= 'A' && chb <= 'Z')
3745                         chb += 'a' - 'A';
3746                 if (cha != chb)
3747                         return cha - chb;
3748         }
3749         if (*namea)
3750                 return 1;                               /* a is longer */
3751         if (*nameb)
3752                 return -1;                              /* b is longer */
3753         return 0;
3754 }
3755
3756
3757 /*
3758  * Initialize GUC options during program startup.
3759  *
3760  * Note that we cannot read the config file yet, since we have not yet
3761  * processed command-line switches.
3762  */
3763 void
3764 InitializeGUCOptions(void)
3765 {
3766         int                     i;
3767
3768         /*
3769          * Before log_line_prefix could possibly receive a nonempty setting, make
3770          * sure that timezone processing is minimally alive (see elog.c).
3771          */
3772         pg_timezone_initialize();
3773
3774         /*
3775          * Build sorted array of all GUC variables.
3776          */
3777         build_guc_variables();
3778
3779         /*
3780          * Load all variables with their compiled-in defaults, and initialize
3781          * status fields as needed.
3782          */
3783         for (i = 0; i < num_guc_variables; i++)
3784         {
3785                 InitializeOneGUCOption(guc_variables[i]);
3786         }
3787
3788         guc_dirty = false;
3789
3790         reporting_enabled = false;
3791
3792         /*
3793          * Prevent any attempt to override the transaction modes from
3794          * non-interactive sources.
3795          */
3796         SetConfigOption("transaction_isolation", "default",
3797                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3798         SetConfigOption("transaction_read_only", "no",
3799                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3800         SetConfigOption("transaction_deferrable", "no",
3801                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3802
3803         /*
3804          * For historical reasons, some GUC parameters can receive defaults from
3805          * environment variables.  Process those settings.
3806          */
3807         InitializeGUCOptionsFromEnvironment();
3808 }
3809
3810 /*
3811  * Assign any GUC values that can come from the server's environment.
3812  *
3813  * This is called from InitializeGUCOptions, and also from ProcessConfigFile
3814  * to deal with the possibility that a setting has been removed from
3815  * postgresql.conf and should now get a value from the environment.
3816  * (The latter is a kludge that should probably go away someday; if so,
3817  * fold this back into InitializeGUCOptions.)
3818  */
3819 static void
3820 InitializeGUCOptionsFromEnvironment(void)
3821 {
3822         char       *env;
3823         long            stack_rlimit;
3824
3825         env = getenv("PGPORT");
3826         if (env != NULL)
3827                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3828
3829         env = getenv("PGDATESTYLE");
3830         if (env != NULL)
3831                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3832
3833         env = getenv("PGCLIENTENCODING");
3834         if (env != NULL)
3835                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3836
3837         /*
3838          * rlimit isn't exactly an "environment variable", but it behaves about
3839          * the same.  If we can identify the platform stack depth rlimit, increase
3840          * default stack depth setting up to whatever is safe (but at most 2MB).
3841          */
3842         stack_rlimit = get_stack_depth_rlimit();
3843         if (stack_rlimit > 0)
3844         {
3845                 long            new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3846
3847                 if (new_limit > 100)
3848                 {
3849                         char            limbuf[16];
3850
3851                         new_limit = Min(new_limit, 2048);
3852                         sprintf(limbuf, "%ld", new_limit);
3853                         SetConfigOption("max_stack_depth", limbuf,
3854                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3855                 }
3856         }
3857 }
3858
3859 /*
3860  * Initialize one GUC option variable to its compiled-in default.
3861  *
3862  * Note: the reason for calling check_hooks is not that we think the boot_val
3863  * might fail, but that the hooks might wish to compute an "extra" struct.
3864  */
3865 static void
3866 InitializeOneGUCOption(struct config_generic * gconf)
3867 {
3868         gconf->status = 0;
3869         gconf->source = PGC_S_DEFAULT;
3870         gconf->reset_source = PGC_S_DEFAULT;
3871         gconf->scontext = PGC_INTERNAL;
3872         gconf->reset_scontext = PGC_INTERNAL;
3873         gconf->stack = NULL;
3874         gconf->extra = NULL;
3875         gconf->sourcefile = NULL;
3876         gconf->sourceline = 0;
3877
3878         switch (gconf->vartype)
3879         {
3880                 case PGC_BOOL:
3881                         {
3882                                 struct config_bool *conf = (struct config_bool *) gconf;
3883                                 bool            newval = conf->boot_val;
3884                                 void       *extra = NULL;
3885
3886                                 if (!call_bool_check_hook(conf, &newval, &extra,
3887                                                                                   PGC_S_DEFAULT, LOG))
3888                                         elog(FATAL, "failed to initialize %s to %d",
3889                                                  conf->gen.name, (int) newval);
3890                                 if (conf->assign_hook)
3891                                         (*conf->assign_hook) (newval, extra);
3892                                 *conf->variable = conf->reset_val = newval;
3893                                 conf->gen.extra = conf->reset_extra = extra;
3894                                 break;
3895                         }
3896                 case PGC_INT:
3897                         {
3898                                 struct config_int *conf = (struct config_int *) gconf;
3899                                 int                     newval = conf->boot_val;
3900                                 void       *extra = NULL;
3901
3902                                 Assert(newval >= conf->min);
3903                                 Assert(newval <= conf->max);
3904                                 if (!call_int_check_hook(conf, &newval, &extra,
3905                                                                                  PGC_S_DEFAULT, LOG))
3906                                         elog(FATAL, "failed to initialize %s to %d",
3907                                                  conf->gen.name, newval);
3908                                 if (conf->assign_hook)
3909                                         (*conf->assign_hook) (newval, extra);
3910                                 *conf->variable = conf->reset_val = newval;
3911                                 conf->gen.extra = conf->reset_extra = extra;
3912                                 break;
3913                         }
3914                 case PGC_REAL:
3915                         {
3916                                 struct config_real *conf = (struct config_real *) gconf;
3917                                 double          newval = conf->boot_val;
3918                                 void       *extra = NULL;
3919
3920                                 Assert(newval >= conf->min);
3921                                 Assert(newval <= conf->max);
3922                                 if (!call_real_check_hook(conf, &newval, &extra,
3923                                                                                   PGC_S_DEFAULT, LOG))
3924                                         elog(FATAL, "failed to initialize %s to %g",
3925                                                  conf->gen.name, newval);
3926                                 if (conf->assign_hook)
3927                                         (*conf->assign_hook) (newval, extra);
3928                                 *conf->variable = conf->reset_val = newval;
3929                                 conf->gen.extra = conf->reset_extra = extra;
3930                                 break;
3931                         }
3932                 case PGC_STRING:
3933                         {
3934                                 struct config_string *conf = (struct config_string *) gconf;
3935                                 char       *newval;
3936                                 void       *extra = NULL;
3937
3938                                 /* non-NULL boot_val must always get strdup'd */
3939                                 if (conf->boot_val != NULL)
3940                                         newval = guc_strdup(FATAL, conf->boot_val);
3941                                 else
3942                                         newval = NULL;
3943
3944                                 if (!call_string_check_hook(conf, &newval, &extra,
3945                                                                                         PGC_S_DEFAULT, LOG))
3946                                         elog(FATAL, "failed to initialize %s to \"%s\"",
3947                                                  conf->gen.name, newval ? newval : "");
3948                                 if (conf->assign_hook)
3949                                         (*conf->assign_hook) (newval, extra);
3950                                 *conf->variable = conf->reset_val = newval;
3951                                 conf->gen.extra = conf->reset_extra = extra;
3952                                 break;
3953                         }
3954                 case PGC_ENUM:
3955                         {
3956                                 struct config_enum *conf = (struct config_enum *) gconf;
3957                                 int                     newval = conf->boot_val;
3958                                 void       *extra = NULL;
3959
3960                                 if (!call_enum_check_hook(conf, &newval, &extra,
3961                                                                                   PGC_S_DEFAULT, LOG))
3962                                         elog(FATAL, "failed to initialize %s to %d",
3963                                                  conf->gen.name, newval);
3964                                 if (conf->assign_hook)
3965                                         (*conf->assign_hook) (newval, extra);
3966                                 *conf->variable = conf->reset_val = newval;
3967                                 conf->gen.extra = conf->reset_extra = extra;
3968                                 break;
3969                         }
3970         }
3971 }
3972
3973
3974 /*
3975  * Select the configuration files and data directory to be used, and
3976  * do the initial read of postgresql.conf.
3977  *
3978  * This is called after processing command-line switches.
3979  *              userDoption is the -D switch value if any (NULL if unspecified).
3980  *              progname is just for use in error messages.
3981  *
3982  * Returns true on success; on failure, prints a suitable error message
3983  * to stderr and returns false.
3984  */
3985 bool
3986 SelectConfigFiles(const char *userDoption, const char *progname)
3987 {
3988         char       *configdir;
3989         char       *fname;
3990         struct stat stat_buf;
3991
3992         /* configdir is -D option, or $PGDATA if no -D */
3993         if (userDoption)
3994                 configdir = make_absolute_path(userDoption);
3995         else
3996                 configdir = make_absolute_path(getenv("PGDATA"));
3997
3998         /*
3999          * Find the configuration file: if config_file was specified on the
4000          * command line, use it, else use configdir/postgresql.conf.  In any case
4001          * ensure the result is an absolute path, so that it will be interpreted
4002          * the same way by future backends.
4003          */
4004         if (ConfigFileName)
4005                 fname = make_absolute_path(ConfigFileName);
4006         else if (configdir)
4007         {
4008                 fname = guc_malloc(FATAL,
4009                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
4010                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
4011         }
4012         else
4013         {
4014                 write_stderr("%s does not know where to find the server configuration file.\n"
4015                                          "You must specify the --config-file or -D invocation "
4016                                          "option or set the PGDATA environment variable.\n",
4017                                          progname);
4018                 return false;
4019         }
4020
4021         /*
4022          * Set the ConfigFileName GUC variable to its final value, ensuring that
4023          * it can't be overridden later.
4024          */
4025         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
4026         free(fname);
4027
4028         /*
4029          * Now read the config file for the first time.
4030          */
4031         if (stat(ConfigFileName, &stat_buf) != 0)
4032         {
4033                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
4034                                          progname, ConfigFileName, strerror(errno));
4035                 return false;
4036         }
4037
4038         ProcessConfigFile(PGC_POSTMASTER);
4039
4040         /*
4041          * If the data_directory GUC variable has been set, use that as DataDir;
4042          * otherwise use configdir if set; else punt.
4043          *
4044          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
4045          * have to.
4046          */
4047         if (data_directory)
4048                 SetDataDir(data_directory);
4049         else if (configdir)
4050                 SetDataDir(configdir);
4051         else
4052         {
4053                 write_stderr("%s does not know where to find the database system data.\n"
4054                                          "This can be specified as \"data_directory\" in \"%s\", "
4055                                          "or by the -D invocation option, or by the "
4056                                          "PGDATA environment variable.\n",
4057                                          progname, ConfigFileName);
4058                 return false;
4059         }
4060
4061         /*
4062          * Reflect the final DataDir value back into the data_directory GUC var.
4063          * (If you are wondering why we don't just make them a single variable,
4064          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
4065          * child backends specially.  XXX is that still true?  Given that we now
4066          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
4067          * DataDir in advance.)
4068          */
4069         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
4070
4071         /*
4072          * If timezone_abbreviations wasn't set in the configuration file, install
4073          * the default value.  We do it this way because we can't safely install
4074          * a "real" value until my_exec_path is set, which may not have happened
4075          * when InitializeGUCOptions runs, so the bootstrap default value cannot
4076          * be the real desired default.
4077          */
4078         pg_timezone_abbrev_initialize();
4079
4080         /*
4081          * Figure out where pg_hba.conf is, and make sure the path is absolute.
4082          */
4083         if (HbaFileName)
4084                 fname = make_absolute_path(HbaFileName);
4085         else if (configdir)
4086         {
4087                 fname = guc_malloc(FATAL,
4088                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
4089                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
4090         }
4091         else
4092         {
4093                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
4094                                          "This can be specified as \"hba_file\" in \"%s\", "
4095                                          "or by the -D invocation option, or by the "
4096                                          "PGDATA environment variable.\n",
4097                                          progname, ConfigFileName);
4098                 return false;
4099         }
4100         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
4101         free(fname);
4102
4103         /*
4104          * Likewise for pg_ident.conf.
4105          */
4106         if (IdentFileName)
4107                 fname = make_absolute_path(IdentFileName);
4108         else if (configdir)
4109         {
4110                 fname = guc_malloc(FATAL,
4111                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
4112                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
4113         }
4114         else
4115         {
4116                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
4117                                          "This can be specified as \"ident_file\" in \"%s\", "
4118                                          "or by the -D invocation option, or by the "
4119                                          "PGDATA environment variable.\n",
4120                                          progname, ConfigFileName);
4121                 return false;
4122         }
4123         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
4124         free(fname);
4125
4126         free(configdir);
4127
4128         return true;
4129 }
4130
4131
4132 /*
4133  * Reset all options to their saved default values (implements RESET ALL)
4134  */
4135 void
4136 ResetAllOptions(void)
4137 {
4138         int                     i;
4139
4140         for (i = 0; i < num_guc_variables; i++)
4141         {
4142                 struct config_generic *gconf = guc_variables[i];
4143
4144                 /* Don't reset non-SET-able values */
4145                 if (gconf->context != PGC_SUSET &&
4146                         gconf->context != PGC_USERSET)
4147                         continue;
4148                 /* Don't reset if special exclusion from RESET ALL */
4149                 if (gconf->flags & GUC_NO_RESET_ALL)
4150                         continue;
4151                 /* No need to reset if wasn't SET */
4152                 if (gconf->source <= PGC_S_OVERRIDE)
4153                         continue;
4154
4155                 /* Save old value to support transaction abort */
4156                 push_old_value(gconf, GUC_ACTION_SET);
4157
4158                 switch (gconf->vartype)
4159                 {
4160                         case PGC_BOOL:
4161                                 {
4162                                         struct config_bool *conf = (struct config_bool *) gconf;
4163
4164                                         if (conf->assign_hook)
4165                                                 (*conf->assign_hook) (conf->reset_val,
4166                                                                                           conf->reset_extra);
4167                                         *conf->variable = conf->reset_val;
4168                                         set_extra_field(&conf->gen, &conf->gen.extra,
4169                                                                         conf->reset_extra);
4170                                         break;
4171                                 }
4172                         case PGC_INT:
4173                                 {
4174                                         struct config_int *conf = (struct config_int *) gconf;
4175
4176                                         if (conf->assign_hook)
4177                                                 (*conf->assign_hook) (conf->reset_val,
4178                                                                                           conf->reset_extra);
4179                                         *conf->variable = conf->reset_val;
4180                                         set_extra_field(&conf->gen, &conf->gen.extra,
4181                                                                         conf->reset_extra);
4182                                         break;
4183                                 }
4184                         case PGC_REAL:
4185                                 {
4186                                         struct config_real *conf = (struct config_real *) gconf;
4187
4188                                         if (conf->assign_hook)
4189                                                 (*conf->assign_hook) (conf->reset_val,
4190                                                                                           conf->reset_extra);
4191                                         *conf->variable = conf->reset_val;
4192                                         set_extra_field(&conf->gen, &conf->gen.extra,
4193                                                                         conf->reset_extra);
4194                                         break;
4195                                 }
4196                         case PGC_STRING:
4197                                 {
4198                                         struct config_string *conf = (struct config_string *) gconf;
4199
4200                                         if (conf->assign_hook)
4201                                                 (*conf->assign_hook) (conf->reset_val,
4202                                                                                           conf->reset_extra);
4203                                         set_string_field(conf, conf->variable, conf->reset_val);
4204                                         set_extra_field(&conf->gen, &conf->gen.extra,
4205                                                                         conf->reset_extra);
4206                                         break;
4207                                 }
4208                         case PGC_ENUM:
4209                                 {
4210                                         struct config_enum *conf = (struct config_enum *) gconf;
4211
4212                                         if (conf->assign_hook)
4213                                                 (*conf->assign_hook) (conf->reset_val,
4214                                                                                           conf->reset_extra);
4215                                         *conf->variable = conf->reset_val;
4216                                         set_extra_field(&conf->gen, &conf->gen.extra,
4217                                                                         conf->reset_extra);
4218                                         break;
4219                                 }
4220                 }
4221
4222                 gconf->source = gconf->reset_source;
4223                 gconf->scontext = gconf->reset_scontext;
4224
4225                 if (gconf->flags & GUC_REPORT)
4226                         ReportGUCOption(gconf);
4227         }
4228 }
4229
4230
4231 /*
4232  * push_old_value
4233  *              Push previous state during transactional assignment to a GUC variable.
4234  */
4235 static void
4236 push_old_value(struct config_generic * gconf, GucAction action)
4237 {
4238         GucStack   *stack;
4239
4240         /* If we're not inside a nest level, do nothing */
4241         if (GUCNestLevel == 0)
4242                 return;
4243
4244         /* Do we already have a stack entry of the current nest level? */
4245         stack = gconf->stack;
4246         if (stack && stack->nest_level >= GUCNestLevel)
4247         {
4248                 /* Yes, so adjust its state if necessary */
4249                 Assert(stack->nest_level == GUCNestLevel);
4250                 switch (action)
4251                 {
4252                         case GUC_ACTION_SET:
4253                                 /* SET overrides any prior action at same nest level */
4254                                 if (stack->state == GUC_SET_LOCAL)
4255                                 {
4256                                         /* must discard old masked value */
4257                                         discard_stack_value(gconf, &stack->masked);
4258                                 }
4259                                 stack->state = GUC_SET;
4260                                 break;
4261                         case GUC_ACTION_LOCAL:
4262                                 if (stack->state == GUC_SET)
4263                                 {
4264                                         /* SET followed by SET LOCAL, remember SET's value */
4265                                         stack->masked_scontext = gconf->scontext;
4266                                         set_stack_value(gconf, &stack->masked);
4267                                         stack->state = GUC_SET_LOCAL;
4268                                 }
4269                                 /* in all other cases, no change to stack entry */
4270                                 break;
4271                         case GUC_ACTION_SAVE:
4272                                 /* Could only have a prior SAVE of same variable */
4273                                 Assert(stack->state == GUC_SAVE);
4274                                 break;
4275                 }
4276                 Assert(guc_dirty);              /* must be set already */
4277                 return;
4278         }
4279
4280         /*
4281          * Push a new stack entry
4282          *
4283          * We keep all the stack entries in TopTransactionContext for simplicity.
4284          */
4285         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
4286                                                                                                 sizeof(GucStack));
4287
4288         stack->prev = gconf->stack;
4289         stack->nest_level = GUCNestLevel;
4290         switch (action)
4291         {
4292                 case GUC_ACTION_SET:
4293                         stack->state = GUC_SET;
4294                         break;
4295                 case GUC_ACTION_LOCAL:
4296                         stack->state = GUC_LOCAL;
4297                         break;
4298                 case GUC_ACTION_SAVE:
4299                         stack->state = GUC_SAVE;
4300                         break;
4301         }
4302         stack->source = gconf->source;
4303         stack->scontext = gconf->scontext;
4304         set_stack_value(gconf, &stack->prior);
4305
4306         gconf->stack = stack;
4307
4308         /* Ensure we remember to pop at end of xact */
4309         guc_dirty = true;
4310 }
4311
4312
4313 /*
4314  * Do GUC processing at main transaction start.
4315  */
4316 void
4317 AtStart_GUC(void)
4318 {
4319         /*
4320          * The nest level should be 0 between transactions; if it isn't, somebody
4321          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
4322          * throw a warning but make no other effort to clean up.
4323          */
4324         if (GUCNestLevel != 0)
4325                 elog(WARNING, "GUC nest level = %d at transaction start",
4326                          GUCNestLevel);
4327         GUCNestLevel = 1;
4328 }
4329
4330 /*
4331  * Enter a new nesting level for GUC values.  This is called at subtransaction
4332  * start and when entering a function that has proconfig settings.      NOTE that
4333  * we must not risk error here, else subtransaction start will be unhappy.
4334  */
4335 int
4336 NewGUCNestLevel(void)
4337 {
4338         return ++GUCNestLevel;
4339 }
4340
4341 /*
4342  * Do GUC processing at transaction or subtransaction commit or abort, or
4343  * when exiting a function that has proconfig settings.  (The name is thus
4344  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
4345  * During abort, we discard all GUC settings that were applied at nesting
4346  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
4347  */
4348 void
4349 AtEOXact_GUC(bool isCommit, int nestLevel)
4350 {
4351         bool            still_dirty;
4352         int                     i;
4353
4354         /*
4355          * Note: it's possible to get here with GUCNestLevel == nestLevel-1 during
4356          * abort, if there is a failure during transaction start before
4357          * AtStart_GUC is called.
4358          */
4359         Assert(nestLevel > 0 &&
4360                    (nestLevel <= GUCNestLevel ||
4361                         (nestLevel == GUCNestLevel + 1 && !isCommit)));
4362
4363         /* Quick exit if nothing's changed in this transaction */
4364         if (!guc_dirty)
4365         {
4366                 GUCNestLevel = nestLevel - 1;
4367                 return;
4368         }
4369
4370         still_dirty = false;
4371         for (i = 0; i < num_guc_variables; i++)
4372         {
4373                 struct config_generic *gconf = guc_variables[i];
4374                 GucStack   *stack;
4375
4376                 /*
4377                  * Process and pop each stack entry within the nest level.      To
4378                  * simplify fmgr_security_definer(), we allow failure exit from a
4379                  * function-with-SET-options to be recovered at the surrounding
4380                  * transaction or subtransaction abort; so there could be more than
4381                  * one stack entry to pop.
4382                  */
4383                 while ((stack = gconf->stack) != NULL &&
4384                            stack->nest_level >= nestLevel)
4385                 {
4386                         GucStack   *prev = stack->prev;
4387                         bool            restorePrior = false;
4388                         bool            restoreMasked = false;
4389                         bool            changed;
4390
4391                         /*
4392                          * In this next bit, if we don't set either restorePrior or
4393                          * restoreMasked, we must "discard" any unwanted fields of the
4394                          * stack entries to avoid leaking memory.  If we do set one of
4395                          * those flags, unused fields will be cleaned up after restoring.
4396                          */
4397                         if (!isCommit)          /* if abort, always restore prior value */
4398                                 restorePrior = true;
4399                         else if (stack->state == GUC_SAVE)
4400                                 restorePrior = true;
4401                         else if (stack->nest_level == 1)
4402                         {
4403                                 /* transaction commit */
4404                                 if (stack->state == GUC_SET_LOCAL)
4405                                         restoreMasked = true;
4406                                 else if (stack->state == GUC_SET)
4407                                 {
4408                                         /* we keep the current active value */
4409                                         discard_stack_value(gconf, &stack->prior);
4410                                 }
4411                                 else    /* must be GUC_LOCAL */
4412                                         restorePrior = true;
4413                         }
4414                         else if (prev == NULL ||
4415                                          prev->nest_level < stack->nest_level - 1)
4416                         {
4417                                 /* decrement entry's level and do not pop it */
4418                                 stack->nest_level--;
4419                                 continue;
4420                         }
4421                         else
4422                         {
4423                                 /*
4424                                  * We have to merge this stack entry into prev. See README for
4425                                  * discussion of this bit.
4426                                  */
4427                                 switch (stack->state)
4428                                 {
4429                                         case GUC_SAVE:
4430                                                 Assert(false);  /* can't get here */
4431
4432                                         case GUC_SET:
4433                                                 /* next level always becomes SET */
4434                                                 discard_stack_value(gconf, &stack->prior);
4435                                                 if (prev->state == GUC_SET_LOCAL)
4436                                                         discard_stack_value(gconf, &prev->masked);
4437                                                 prev->state = GUC_SET;
4438                                                 break;
4439
4440                                         case GUC_LOCAL:
4441                                                 if (prev->state == GUC_SET)
4442                                                 {
4443                                                         /* LOCAL migrates down */
4444                                                         prev->masked_scontext = stack->scontext;
4445                                                         prev->masked = stack->prior;
4446                                                         prev->state = GUC_SET_LOCAL;
4447                                                 }
4448                                                 else
4449                                                 {
4450                                                         /* else just forget this stack level */
4451                                                         discard_stack_value(gconf, &stack->prior);
4452                                                 }
4453                                                 break;
4454
4455                                         case GUC_SET_LOCAL:
4456                                                 /* prior state at this level no longer wanted */
4457                                                 discard_stack_value(gconf, &stack->prior);
4458                                                 /* copy down the masked state */
4459                                                 prev->masked_scontext = stack->masked_scontext;
4460                                                 if (prev->state == GUC_SET_LOCAL)
4461                                                         discard_stack_value(gconf, &prev->masked);
4462                                                 prev->masked = stack->masked;
4463                                                 prev->state = GUC_SET_LOCAL;
4464                                                 break;
4465                                 }
4466                         }
4467
4468                         changed = false;
4469
4470                         if (restorePrior || restoreMasked)
4471                         {
4472                                 /* Perform appropriate restoration of the stacked value */
4473                                 config_var_value newvalue;
4474                                 GucSource       newsource;
4475                                 GucContext      newscontext;
4476
4477                                 if (restoreMasked)
4478                                 {
4479                                         newvalue = stack->masked;
4480                                         newsource = PGC_S_SESSION;
4481                                         newscontext = stack->masked_scontext;
4482                                 }
4483                                 else
4484                                 {
4485                                         newvalue = stack->prior;
4486                                         newsource = stack->source;
4487                                         newscontext = stack->scontext;
4488                                 }
4489
4490                                 switch (gconf->vartype)
4491                                 {
4492                                         case PGC_BOOL:
4493                                                 {
4494                                                         struct config_bool *conf = (struct config_bool *) gconf;
4495                                                         bool            newval = newvalue.val.boolval;
4496                                                         void       *newextra = newvalue.extra;
4497
4498                                                         if (*conf->variable != newval ||
4499                                                                 conf->gen.extra != newextra)
4500                                                         {
4501                                                                 if (conf->assign_hook)
4502                                                                         (*conf->assign_hook) (newval, newextra);
4503                                                                 *conf->variable = newval;
4504                                                                 set_extra_field(&conf->gen, &conf->gen.extra,
4505                                                                                                 newextra);
4506                                                                 changed = true;
4507                                                         }
4508                                                         break;
4509                                                 }
4510                                         case PGC_INT:
4511                                                 {
4512                                                         struct config_int *conf = (struct config_int *) gconf;
4513                                                         int                     newval = newvalue.val.intval;
4514                                                         void       *newextra = newvalue.extra;
4515
4516                                                         if (*conf->variable != newval ||
4517                                                                 conf->gen.extra != newextra)
4518                                                         {
4519                                                                 if (conf->assign_hook)
4520                                                                         (*conf->assign_hook) (newval, newextra);
4521                                                                 *conf->variable = newval;
4522                                                                 set_extra_field(&conf->gen, &conf->gen.extra,
4523                                                                                                 newextra);
4524                                                                 changed = true;
4525                                                         }
4526                                                         break;
4527                                                 }
4528                                         case PGC_REAL:
4529                                                 {
4530                                                         struct config_real *conf = (struct config_real *) gconf;
4531                                                         double          newval = newvalue.val.realval;
4532                                                         void       *newextra = newvalue.extra;
4533
4534                                                         if (*conf->variable != newval ||
4535                                                                 conf->gen.extra != newextra)
4536                                                         {
4537                                                                 if (conf->assign_hook)
4538                                                                         (*conf->assign_hook) (newval, newextra);
4539                                                                 *conf->variable = newval;
4540                                                                 set_extra_field(&conf->gen, &conf->gen.extra,
4541                                                                                                 newextra);
4542                                                                 changed = true;
4543                                                         }
4544                                                         break;
4545                                                 }
4546                                         case PGC_STRING:
4547                                                 {
4548                                                         struct config_string *conf = (struct config_string *) gconf;
4549                                                         char       *newval = newvalue.val.stringval;
4550                                                         void       *newextra = newvalue.extra;
4551
4552                                                         if (*conf->variable != newval ||
4553                                                                 conf->gen.extra != newextra)
4554                                                         {
4555                                                                 if (conf->assign_hook)
4556                                                                         (*conf->assign_hook) (newval, newextra);
4557                                                                 set_string_field(conf, conf->variable, newval);
4558                                                                 set_extra_field(&conf->gen, &conf->gen.extra,
4559                                                                                                 newextra);
4560                                                                 changed = true;
4561                                                         }
4562
4563                                                         /*
4564                                                          * Release stacked values if not used anymore. We
4565                                                          * could use discard_stack_value() here, but since
4566                                                          * we have type-specific code anyway, might as
4567                                                          * well inline it.
4568                                                          */
4569                                                         set_string_field(conf, &stack->prior.val.stringval, NULL);
4570                                                         set_string_field(conf, &stack->masked.val.stringval, NULL);
4571                                                         break;
4572                                                 }
4573                                         case PGC_ENUM:
4574                                                 {
4575                                                         struct config_enum *conf = (struct config_enum *) gconf;
4576                                                         int                     newval = newvalue.val.enumval;
4577                                                         void       *newextra = newvalue.extra;
4578
4579                                                         if (*conf->variable != newval ||
4580                                                                 conf->gen.extra != newextra)
4581                                                         {
4582                                                                 if (conf->assign_hook)
4583                                                                         (*conf->assign_hook) (newval, newextra);
4584                                                                 *conf->variable = newval;
4585                                                                 set_extra_field(&conf->gen, &conf->gen.extra,
4586                                                                                                 newextra);
4587                                                                 changed = true;
4588                                                         }
4589                                                         break;
4590                                                 }
4591                                 }
4592
4593                                 /*
4594                                  * Release stacked extra values if not used anymore.
4595                                  */
4596                                 set_extra_field(gconf, &(stack->prior.extra), NULL);
4597                                 set_extra_field(gconf, &(stack->masked.extra), NULL);
4598
4599                                 /* And restore source information */
4600                                 gconf->source = newsource;
4601                                 gconf->scontext = newscontext;
4602                         }
4603
4604                         /* Finish popping the state stack */
4605                         gconf->stack = prev;
4606                         pfree(stack);
4607
4608                         /* Report new value if we changed it */
4609                         if (changed && (gconf->flags & GUC_REPORT))
4610                                 ReportGUCOption(gconf);
4611                 }                                               /* end of stack-popping loop */
4612
4613                 if (stack != NULL)
4614                         still_dirty = true;
4615         }
4616
4617         /* If there are no remaining stack entries, we can reset guc_dirty */
4618         guc_dirty = still_dirty;
4619
4620         /* Update nesting level */
4621         GUCNestLevel = nestLevel - 1;
4622 }
4623
4624
4625 /*
4626  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4627  * This is executed at completion of backend startup.
4628  */
4629 void
4630 BeginReportingGUCOptions(void)
4631 {
4632         int                     i;
4633
4634         /*
4635          * Don't do anything unless talking to an interactive frontend of protocol
4636          * 3.0 or later.
4637          */
4638         if (whereToSendOutput != DestRemote ||
4639                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4640                 return;
4641
4642         reporting_enabled = true;
4643
4644         /* Transmit initial values of interesting variables */
4645         for (i = 0; i < num_guc_variables; i++)
4646         {
4647                 struct config_generic *conf = guc_variables[i];
4648
4649                 if (conf->flags & GUC_REPORT)
4650                         ReportGUCOption(conf);
4651         }
4652 }
4653
4654 /*
4655  * ReportGUCOption: if appropriate, transmit option value to frontend
4656  */
4657 static void
4658 ReportGUCOption(struct config_generic * record)
4659 {
4660         if (reporting_enabled && (record->flags & GUC_REPORT))
4661         {
4662                 char       *val = _ShowOption(record, false);
4663                 StringInfoData msgbuf;
4664
4665                 pq_beginmessage(&msgbuf, 'S');
4666                 pq_sendstring(&msgbuf, record->name);
4667                 pq_sendstring(&msgbuf, val);
4668                 pq_endmessage(&msgbuf);
4669
4670                 pfree(val);
4671         }
4672 }
4673
4674 /*
4675  * Try to parse value as an integer.  The accepted formats are the
4676  * usual decimal, octal, or hexadecimal formats, optionally followed by
4677  * a unit name if "flags" indicates a unit is allowed.
4678  *
4679  * If the string parses okay, return true, else false.
4680  * If okay and result is not NULL, return the value in *result.
4681  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4682  *      HINT message, or NULL if no hint provided.
4683  */
4684 bool
4685 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4686 {
4687         int64           val;
4688         char       *endptr;
4689
4690         /* To suppress compiler warnings, always set output params */
4691         if (result)
4692                 *result = 0;
4693         if (hintmsg)
4694                 *hintmsg = NULL;
4695
4696         /* We assume here that int64 is at least as wide as long */
4697         errno = 0;
4698         val = strtol(value, &endptr, 0);
4699
4700         if (endptr == value)
4701                 return false;                   /* no HINT for integer syntax error */
4702
4703         if (errno == ERANGE || val != (int64) ((int32) val))
4704         {
4705                 if (hintmsg)
4706                         *hintmsg = gettext_noop("Value exceeds integer range.");
4707                 return false;
4708         }
4709
4710         /* allow whitespace between integer and unit */
4711         while (isspace((unsigned char) *endptr))
4712                 endptr++;
4713
4714         /* Handle possible unit */
4715         if (*endptr != '\0')
4716         {
4717                 /*
4718                  * Note: the multiple-switch coding technique here is a bit tedious,
4719                  * but seems necessary to avoid intermediate-value overflows.
4720                  */
4721                 if (flags & GUC_UNIT_MEMORY)
4722                 {
4723                         /* Set hint for use if no match or trailing garbage */
4724                         if (hintmsg)
4725                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4726
4727 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4728 #error BLCKSZ must be between 1KB and 1MB
4729 #endif
4730 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4731 #error XLOG_BLCKSZ must be between 1KB and 1MB
4732 #endif
4733
4734                         if (strncmp(endptr, "kB", 2) == 0)
4735                         {
4736                                 endptr += 2;
4737                                 switch (flags & GUC_UNIT_MEMORY)
4738                                 {
4739                                         case GUC_UNIT_BLOCKS:
4740                                                 val /= (BLCKSZ / 1024);
4741                                                 break;
4742                                         case GUC_UNIT_XBLOCKS:
4743                                                 val /= (XLOG_BLCKSZ / 1024);
4744                                                 break;
4745                                 }
4746                         }
4747                         else if (strncmp(endptr, "MB", 2) == 0)
4748                         {
4749                                 endptr += 2;
4750                                 switch (flags & GUC_UNIT_MEMORY)
4751                                 {
4752                                         case GUC_UNIT_KB:
4753                                                 val *= KB_PER_MB;
4754                                                 break;
4755                                         case GUC_UNIT_BLOCKS:
4756                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4757                                                 break;
4758                                         case GUC_UNIT_XBLOCKS:
4759                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4760                                                 break;
4761                                 }
4762                         }
4763                         else if (strncmp(endptr, "GB", 2) == 0)
4764                         {
4765                                 endptr += 2;
4766                                 switch (flags & GUC_UNIT_MEMORY)
4767                                 {
4768                                         case GUC_UNIT_KB:
4769                                                 val *= KB_PER_GB;
4770                                                 break;
4771                                         case GUC_UNIT_BLOCKS:
4772                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4773                                                 break;
4774                                         case GUC_UNIT_XBLOCKS:
4775                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4776                                                 break;
4777                                 }
4778                         }
4779                 }
4780                 else if (flags & GUC_UNIT_TIME)
4781                 {
4782                         /* Set hint for use if no match or trailing garbage */
4783                         if (hintmsg)
4784                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4785
4786                         if (strncmp(endptr, "ms", 2) == 0)
4787                         {
4788                                 endptr += 2;
4789                                 switch (flags & GUC_UNIT_TIME)
4790                                 {
4791                                         case GUC_UNIT_S:
4792                                                 val /= MS_PER_S;
4793                                                 break;
4794                                         case GUC_UNIT_MIN:
4795                                                 val /= MS_PER_MIN;
4796                                                 break;
4797                                 }
4798                         }
4799                         else if (strncmp(endptr, "s", 1) == 0)
4800                         {
4801                                 endptr += 1;
4802                                 switch (flags & GUC_UNIT_TIME)
4803                                 {
4804                                         case GUC_UNIT_MS:
4805                                                 val *= MS_PER_S;
4806                                                 break;
4807                                         case GUC_UNIT_MIN:
4808                                                 val /= S_PER_MIN;
4809                                                 break;
4810                                 }
4811                         }
4812                         else if (strncmp(endptr, "min", 3) == 0)
4813                         {
4814                                 endptr += 3;
4815                                 switch (flags & GUC_UNIT_TIME)
4816                                 {
4817                                         case GUC_UNIT_MS:
4818                                                 val *= MS_PER_MIN;
4819                                                 break;
4820                                         case GUC_UNIT_S:
4821                                                 val *= S_PER_MIN;
4822                                                 break;
4823                                 }
4824                         }
4825                         else if (strncmp(endptr, "h", 1) == 0)
4826                         {
4827                                 endptr += 1;
4828                                 switch (flags & GUC_UNIT_TIME)
4829                                 {
4830                                         case GUC_UNIT_MS:
4831                                                 val *= MS_PER_H;
4832                                                 break;
4833                                         case GUC_UNIT_S:
4834                                                 val *= S_PER_H;
4835                                                 break;
4836                                         case GUC_UNIT_MIN:
4837                                                 val *= MIN_PER_H;
4838                                                 break;
4839                                 }
4840                         }
4841                         else if (strncmp(endptr, "d", 1) == 0)
4842                         {
4843                                 endptr += 1;
4844                                 switch (flags & GUC_UNIT_TIME)
4845                                 {
4846                                         case GUC_UNIT_MS:
4847                                                 val *= MS_PER_D;
4848                                                 break;
4849                                         case GUC_UNIT_S:
4850                                                 val *= S_PER_D;
4851                                                 break;
4852                                         case GUC_UNIT_MIN:
4853                                                 val *= MIN_PER_D;
4854                                                 break;
4855                                 }
4856                         }
4857                 }
4858
4859                 /* allow whitespace after unit */
4860                 while (isspace((unsigned char) *endptr))
4861                         endptr++;
4862
4863                 if (*endptr != '\0')
4864                         return false;           /* appropriate hint, if any, already set */
4865
4866                 /* Check for overflow due to units conversion */
4867                 if (val != (int64) ((int32) val))
4868                 {
4869                         if (hintmsg)
4870                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4871                         return false;
4872                 }
4873         }
4874
4875         if (result)
4876                 *result = (int) val;
4877         return true;
4878 }
4879
4880
4881
4882 /*
4883  * Try to parse value as a floating point number in the usual format.
4884  * If the string parses okay, return true, else false.
4885  * If okay and result is not NULL, return the value in *result.
4886  */
4887 bool
4888 parse_real(const char *value, double *result)
4889 {
4890         double          val;
4891         char       *endptr;
4892
4893         if (result)
4894                 *result = 0;                    /* suppress compiler warning */
4895
4896         errno = 0;
4897         val = strtod(value, &endptr);
4898         if (endptr == value || errno == ERANGE)
4899                 return false;
4900
4901         /* allow whitespace after number */
4902         while (isspace((unsigned char) *endptr))
4903                 endptr++;
4904         if (*endptr != '\0')
4905                 return false;
4906
4907         if (result)
4908                 *result = val;
4909         return true;
4910 }
4911
4912
4913 /*
4914  * Lookup the name for an enum option with the selected value.
4915  * Should only ever be called with known-valid values, so throws
4916  * an elog(ERROR) if the enum option is not found.
4917  *
4918  * The returned string is a pointer to static data and not
4919  * allocated for modification.
4920  */
4921 const char *
4922 config_enum_lookup_by_value(struct config_enum * record, int val)
4923 {
4924         const struct config_enum_entry *entry;
4925
4926         for (entry = record->options; entry && entry->name; entry++)
4927         {
4928                 if (entry->val == val)
4929                         return entry->name;
4930         }
4931
4932         elog(ERROR, "could not find enum option %d for %s",
4933                  val, record->gen.name);
4934         return NULL;                            /* silence compiler */
4935 }
4936
4937
4938 /*
4939  * Lookup the value for an enum option with the selected name
4940  * (case-insensitive).
4941  * If the enum option is found, sets the retval value and returns
4942  * true. If it's not found, return FALSE and retval is set to 0.
4943  */
4944 bool
4945 config_enum_lookup_by_name(struct config_enum * record, const char *value,
4946                                                    int *retval)
4947 {
4948         const struct config_enum_entry *entry;
4949
4950         for (entry = record->options; entry && entry->name; entry++)
4951         {
4952                 if (pg_strcasecmp(value, entry->name) == 0)
4953                 {
4954                         *retval = entry->val;
4955                         return TRUE;
4956                 }
4957         }
4958
4959         *retval = 0;
4960         return FALSE;
4961 }
4962
4963
4964 /*
4965  * Return a list of all available options for an enum, excluding
4966  * hidden ones, separated by the given separator.
4967  * If prefix is non-NULL, it is added before the first enum value.
4968  * If suffix is non-NULL, it is added to the end of the string.
4969  */
4970 static char *
4971 config_enum_get_options(struct config_enum * record, const char *prefix,
4972                                                 const char *suffix, const char *separator)
4973 {
4974         const struct config_enum_entry *entry;
4975         StringInfoData retstr;
4976         int                     seplen;
4977
4978         initStringInfo(&retstr);
4979         appendStringInfoString(&retstr, prefix);
4980
4981         seplen = strlen(separator);
4982         for (entry = record->options; entry && entry->name; entry++)
4983         {
4984                 if (!entry->hidden)
4985                 {
4986                         appendStringInfoString(&retstr, entry->name);
4987                         appendBinaryStringInfo(&retstr, separator, seplen);
4988                 }
4989         }
4990
4991         /*
4992          * All the entries may have been hidden, leaving the string empty if no
4993          * prefix was given. This indicates a broken GUC setup, since there is no
4994          * use for an enum without any values, so we just check to make sure we
4995          * don't write to invalid memory instead of actually trying to do
4996          * something smart with it.
4997          */
4998         if (retstr.len >= seplen)
4999         {
5000                 /* Replace final separator */
5001                 retstr.data[retstr.len - seplen] = '\0';
5002                 retstr.len -= seplen;
5003         }
5004
5005         appendStringInfoString(&retstr, suffix);
5006
5007         return retstr.data;
5008 }
5009
5010
5011 /*
5012  * Sets option `name' to given value.
5013  *
5014  * The value should be a string, which will be parsed and converted to
5015  * the appropriate data type.  The context and source parameters indicate
5016  * in which context this function is being called, so that it can apply the
5017  * access restrictions properly.
5018  *
5019  * If value is NULL, set the option to its default value (normally the
5020  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
5021  *
5022  * action indicates whether to set the value globally in the session, locally
5023  * to the current top transaction, or just for the duration of a function call.
5024  *
5025  * If changeVal is false then don't really set the option but do all
5026  * the checks to see if it would work.
5027  *
5028  * elevel should normally be passed as zero, allowing this function to make
5029  * its standard choice of ereport level.  However some callers need to be
5030  * able to override that choice; they should pass the ereport level to use.
5031  *
5032  * Return value:
5033  *      +1: the value is valid and was successfully applied.
5034  *      0:  the name or value is invalid (but see below).
5035  *      -1: the value was not applied because of context, priority, or changeVal.
5036  *
5037  * If there is an error (non-existing option, invalid value) then an
5038  * ereport(ERROR) is thrown *unless* this is called for a source for which
5039  * we don't want an ERROR (currently, those are defaults, the config file,
5040  * and per-database or per-user settings, as well as callers who specify
5041  * a less-than-ERROR elevel).  In those cases we write a suitable error
5042  * message via ereport() and return 0.
5043  *
5044  * See also SetConfigOption for an external interface.
5045  */
5046 int
5047 set_config_option(const char *name, const char *value,
5048                                   GucContext context, GucSource source,
5049                                   GucAction action, bool changeVal, int elevel)
5050 {
5051         struct config_generic *record;
5052         bool            prohibitValueChange = false;
5053         bool            makeDefault;
5054
5055         if (elevel == 0)
5056         {
5057                 if (source == PGC_S_DEFAULT || source == PGC_S_FILE)
5058                 {
5059                         /*
5060                          * To avoid cluttering the log, only the postmaster bleats loudly
5061                          * about problems with the config file.
5062                          */
5063                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5064                 }
5065                 else if (source == PGC_S_DATABASE || source == PGC_S_USER ||
5066                                  source == PGC_S_DATABASE_USER)
5067                         elevel = WARNING;
5068                 else
5069                         elevel = ERROR;
5070         }
5071
5072         record = find_option(name, true, elevel);
5073         if (record == NULL)
5074         {
5075                 ereport(elevel,
5076                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5077                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5078                 return 0;
5079         }
5080
5081         /*
5082          * Check if the option can be set at this time. See guc.h for the precise
5083          * rules.
5084          */
5085         switch (record->context)
5086         {
5087                 case PGC_INTERNAL:
5088                         if (context != PGC_INTERNAL)
5089                         {
5090                                 ereport(elevel,
5091                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5092                                                  errmsg("parameter \"%s\" cannot be changed",
5093                                                                 name)));
5094                                 return 0;
5095                         }
5096                         break;
5097                 case PGC_POSTMASTER:
5098                         if (context == PGC_SIGHUP)
5099                         {
5100                                 /*
5101                                  * We are re-reading a PGC_POSTMASTER variable from
5102                                  * postgresql.conf.  We can't change the setting, so we should
5103                                  * give a warning if the DBA tries to change it.  However,
5104                                  * because of variant formats, canonicalization by check
5105                                  * hooks, etc, we can't just compare the given string directly
5106                                  * to what's stored.  Set a flag to check below after we have
5107                                  * the final storable value.
5108                                  */
5109                                 prohibitValueChange = true;
5110                         }
5111                         else if (context != PGC_POSTMASTER)
5112                         {
5113                                 ereport(elevel,
5114                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5115                                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
5116                                                                 name)));
5117                                 return 0;
5118                         }
5119                         break;
5120                 case PGC_SIGHUP:
5121                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
5122                         {
5123                                 ereport(elevel,
5124                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5125                                                  errmsg("parameter \"%s\" cannot be changed now",
5126                                                                 name)));
5127                                 return 0;
5128                         }
5129
5130                         /*
5131                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
5132                          * can be changed after postmaster start". But there's nothing
5133                          * that prevents a crafty administrator from sending SIGHUP
5134                          * signals to individual backends only.
5135                          */
5136                         break;
5137                 case PGC_BACKEND:
5138                         if (context == PGC_SIGHUP)
5139                         {
5140                                 /*
5141                                  * If a PGC_BACKEND parameter is changed in the config file,
5142                                  * we want to accept the new value in the postmaster (whence
5143                                  * it will propagate to subsequently-started backends), but
5144                                  * ignore it in existing backends.      This is a tad klugy, but
5145                                  * necessary because we don't re-read the config file during
5146                                  * backend start.
5147                                  */
5148                                 if (IsUnderPostmaster)
5149                                         return -1;
5150                         }
5151                         else if (context != PGC_POSTMASTER && context != PGC_BACKEND &&
5152                                          source != PGC_S_CLIENT)
5153                         {
5154                                 ereport(elevel,
5155                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5156                                                  errmsg("parameter \"%s\" cannot be set after connection start",
5157                                                                 name)));
5158                                 return 0;
5159                         }
5160                         break;
5161                 case PGC_SUSET:
5162                         if (context == PGC_USERSET || context == PGC_BACKEND)
5163                         {
5164                                 ereport(elevel,
5165                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5166                                                  errmsg("permission denied to set parameter \"%s\"",
5167                                                                 name)));
5168                                 return 0;
5169                         }
5170                         break;
5171                 case PGC_USERSET:
5172                         /* always okay */
5173                         break;
5174         }
5175
5176         /*
5177          * Disallow changing GUC_NOT_WHILE_SEC_REST values if we are inside a
5178          * security restriction context.  We can reject this regardless of the GUC
5179          * context or source, mainly because sources that it might be reasonable
5180          * to override for won't be seen while inside a function.
5181          *
5182          * Note: variables marked GUC_NOT_WHILE_SEC_REST should usually be marked
5183          * GUC_NO_RESET_ALL as well, because ResetAllOptions() doesn't check this.
5184          * An exception might be made if the reset value is assumed to be "safe".
5185          *
5186          * Note: this flag is currently used for "session_authorization" and
5187          * "role".      We need to prohibit changing these inside a local userid
5188          * context because when we exit it, GUC won't be notified, leaving things
5189          * out of sync.  (This could be fixed by forcing a new GUC nesting level,
5190          * but that would change behavior in possibly-undesirable ways.)  Also, we
5191          * prohibit changing these in a security-restricted operation because
5192          * otherwise RESET could be used to regain the session user's privileges.
5193          */
5194         if (record->flags & GUC_NOT_WHILE_SEC_REST)
5195         {
5196                 if (InLocalUserIdChange())
5197                 {
5198                         /*
5199                          * Phrasing of this error message is historical, but it's the most
5200                          * common case.
5201                          */
5202                         ereport(elevel,
5203                                         (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5204                                          errmsg("cannot set parameter \"%s\" within security-definer function",
5205                                                         name)));
5206                         return 0;
5207                 }
5208                 if (InSecurityRestrictedOperation())
5209                 {
5210                         ereport(elevel,
5211                                         (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5212                                          errmsg("cannot set parameter \"%s\" within security-restricted operation",
5213                                                         name)));
5214                         return 0;
5215                 }
5216         }
5217
5218         /*
5219          * Should we set reset/stacked values?  (If so, the behavior is not
5220          * transactional.)      This is done either when we get a default value from
5221          * the database's/user's/client's default settings or when we reset a
5222          * value to its default.
5223          */
5224         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
5225                 ((value != NULL) || source == PGC_S_DEFAULT);
5226
5227         /*
5228          * Ignore attempted set if overridden by previously processed setting.
5229          * However, if changeVal is false then plow ahead anyway since we are
5230          * trying to find out if the value is potentially good, not actually use
5231          * it. Also keep going if makeDefault is true, since we may want to set
5232          * the reset/stacked values even if we can't set the variable itself.
5233          */
5234         if (record->source > source)
5235         {
5236                 if (changeVal && !makeDefault)
5237                 {
5238                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
5239                                  name);
5240                         return -1;
5241                 }
5242                 changeVal = false;
5243         }
5244
5245         /*
5246          * Evaluate value and set variable.
5247          */
5248         switch (record->vartype)
5249         {
5250                 case PGC_BOOL:
5251                         {
5252                                 struct config_bool *conf = (struct config_bool *) record;
5253                                 bool            newval;
5254                                 void       *newextra = NULL;
5255
5256                                 if (value)
5257                                 {
5258                                         if (!parse_bool(value, &newval))
5259                                         {
5260                                                 ereport(elevel,
5261                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5262                                                   errmsg("parameter \"%s\" requires a Boolean value",
5263                                                                  name)));
5264                                                 return 0;
5265                                         }
5266                                         if (!call_bool_check_hook(conf, &newval, &newextra,
5267                                                                                           source, elevel))
5268                                                 return 0;
5269                                 }
5270                                 else if (source == PGC_S_DEFAULT)
5271                                 {
5272                                         newval = conf->boot_val;
5273                                         if (!call_bool_check_hook(conf, &newval, &newextra,
5274                                                                                           source, elevel))
5275                                                 return 0;
5276                                 }
5277                                 else
5278                                 {
5279                                         newval = conf->reset_val;
5280                                         newextra = conf->reset_extra;
5281                                         source = conf->gen.reset_source;
5282                                         context = conf->gen.reset_scontext;
5283                                 }
5284
5285                                 if (prohibitValueChange)
5286                                 {
5287                                         if (*conf->variable != newval)
5288                                         {
5289                                                 ereport(elevel,
5290                                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5291                                                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
5292                                                                                 name)));
5293                                                 return 0;
5294                                         }
5295                                         return -1;
5296                                 }
5297
5298                                 if (changeVal)
5299                                 {
5300                                         /* Save old value to support transaction abort */
5301                                         if (!makeDefault)
5302                                                 push_old_value(&conf->gen, action);
5303
5304                                         if (conf->assign_hook)
5305                                                 (*conf->assign_hook) (newval, newextra);
5306                                         *conf->variable = newval;
5307                                         set_extra_field(&conf->gen, &conf->gen.extra,
5308                                                                         newextra);
5309                                         conf->gen.source = source;
5310                                         conf->gen.scontext = context;
5311                                 }
5312                                 if (makeDefault)
5313                                 {
5314                                         GucStack   *stack;
5315
5316                                         if (conf->gen.reset_source <= source)
5317                                         {
5318                                                 conf->reset_val = newval;
5319                                                 set_extra_field(&conf->gen, &conf->reset_extra,
5320                                                                                 newextra);
5321                                                 conf->gen.reset_source = source;
5322                                                 conf->gen.reset_scontext = context;
5323                                         }
5324                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5325                                         {
5326                                                 if (stack->source <= source)
5327                                                 {
5328                                                         stack->prior.val.boolval = newval;
5329                                                         set_extra_field(&conf->gen, &stack->prior.extra,
5330                                                                                         newextra);
5331                                                         stack->source = source;
5332                                                         stack->scontext = context;
5333                                                 }
5334                                         }
5335                                 }
5336
5337                                 /* Perhaps we didn't install newextra anywhere */
5338                                 if (newextra && !extra_field_used(&conf->gen, newextra))
5339                                         free(newextra);
5340                                 break;
5341                         }
5342
5343                 case PGC_INT:
5344                         {
5345                                 struct config_int *conf = (struct config_int *) record;
5346                                 int                     newval;
5347                                 void       *newextra = NULL;
5348
5349                                 if (value)
5350                                 {
5351                                         const char *hintmsg;
5352
5353                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
5354                                         {
5355                                                 ereport(elevel,
5356                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5357                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5358                                                                 name, value),
5359                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5360                                                 return 0;
5361                                         }
5362                                         if (newval < conf->min || newval > conf->max)
5363                                         {
5364                                                 ereport(elevel,
5365                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5366                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
5367                                                                                 newval, name, conf->min, conf->max)));
5368                                                 return 0;
5369                                         }
5370                                         if (!call_int_check_hook(conf, &newval, &newextra,
5371                                                                                          source, elevel))
5372                                                 return 0;
5373                                 }
5374                                 else if (source == PGC_S_DEFAULT)
5375                                 {
5376                                         newval = conf->boot_val;
5377                                         if (!call_int_check_hook(conf, &newval, &newextra,
5378                                                                                          source, elevel))
5379                                                 return 0;
5380                                 }
5381                                 else
5382                                 {
5383                                         newval = conf->reset_val;
5384                                         newextra = conf->reset_extra;
5385                                         source = conf->gen.reset_source;
5386                                         context = conf->gen.reset_scontext;
5387                                 }
5388
5389                                 if (prohibitValueChange)
5390                                 {
5391                                         if (*conf->variable != newval)
5392                                         {
5393                                                 ereport(elevel,
5394                                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5395                                                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
5396                                                                                 name)));
5397                                                 return 0;
5398                                         }
5399                                         return -1;
5400                                 }
5401
5402                                 if (changeVal)
5403                                 {
5404                                         /* Save old value to support transaction abort */
5405                                         if (!makeDefault)
5406                                                 push_old_value(&conf->gen, action);
5407
5408                                         if (conf->assign_hook)
5409                                                 (*conf->assign_hook) (newval, newextra);
5410                                         *conf->variable = newval;
5411                                         set_extra_field(&conf->gen, &conf->gen.extra,
5412                                                                         newextra);
5413                                         conf->gen.source = source;
5414                                         conf->gen.scontext = context;
5415                                 }
5416                                 if (makeDefault)
5417                                 {
5418                                         GucStack   *stack;
5419
5420                                         if (conf->gen.reset_source <= source)
5421                                         {
5422                                                 conf->reset_val = newval;
5423                                                 set_extra_field(&conf->gen, &conf->reset_extra,
5424                                                                                 newextra);
5425                                                 conf->gen.reset_source = source;
5426                                                 conf->gen.reset_scontext = context;
5427                                         }
5428                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5429                                         {
5430                                                 if (stack->source <= source)
5431                                                 {
5432                                                         stack->prior.val.intval = newval;
5433                                                         set_extra_field(&conf->gen, &stack->prior.extra,
5434                                                                                         newextra);
5435                                                         stack->source = source;
5436                                                         stack->scontext = context;
5437                                                 }
5438                                         }
5439                                 }
5440
5441                                 /* Perhaps we didn't install newextra anywhere */
5442                                 if (newextra && !extra_field_used(&conf->gen, newextra))
5443                                         free(newextra);
5444                                 break;
5445                         }
5446
5447                 case PGC_REAL:
5448                         {
5449                                 struct config_real *conf = (struct config_real *) record;
5450                                 double          newval;
5451                                 void       *newextra = NULL;
5452
5453                                 if (value)
5454                                 {
5455                                         if (!parse_real(value, &newval))
5456                                         {
5457                                                 ereport(elevel,
5458                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5459                                                   errmsg("parameter \"%s\" requires a numeric value",
5460                                                                  name)));
5461                                                 return 0;
5462                                         }
5463                                         if (newval < conf->min || newval > conf->max)
5464                                         {
5465                                                 ereport(elevel,
5466                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5467                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
5468                                                                                 newval, name, conf->min, conf->max)));
5469                                                 return 0;
5470                                         }
5471                                         if (!call_real_check_hook(conf, &newval, &newextra,
5472                                                                                           source, elevel))
5473                                                 return 0;
5474                                 }
5475                                 else if (source == PGC_S_DEFAULT)
5476                                 {
5477                                         newval = conf->boot_val;
5478                                         if (!call_real_check_hook(conf, &newval, &newextra,
5479                                                                                           source, elevel))
5480                                                 return 0;
5481                                 }
5482                                 else
5483                                 {
5484                                         newval = conf->reset_val;
5485                                         newextra = conf->reset_extra;
5486                                         source = conf->gen.reset_source;
5487                                         context = conf->gen.reset_scontext;
5488                                 }
5489
5490                                 if (prohibitValueChange)
5491                                 {
5492                                         if (*conf->variable != newval)
5493                                         {
5494                                                 ereport(elevel,
5495                                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5496                                                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
5497                                                                                 name)));
5498                                                 return 0;
5499                                         }
5500                                         return -1;
5501                                 }
5502
5503                                 if (changeVal)
5504                                 {
5505                                         /* Save old value to support transaction abort */
5506                                         if (!makeDefault)
5507                                                 push_old_value(&conf->gen, action);
5508
5509                                         if (conf->assign_hook)
5510                                                 (*conf->assign_hook) (newval, newextra);
5511                                         *conf->variable = newval;
5512                                         set_extra_field(&conf->gen, &conf->gen.extra,
5513                                                                         newextra);
5514                                         conf->gen.source = source;
5515                                         conf->gen.scontext = context;
5516                                 }
5517                                 if (makeDefault)
5518                                 {
5519                                         GucStack   *stack;
5520
5521                                         if (conf->gen.reset_source <= source)
5522                                         {
5523                                                 conf->reset_val = newval;
5524                                                 set_extra_field(&conf->gen, &conf->reset_extra,
5525                                                                                 newextra);
5526                                                 conf->gen.reset_source = source;
5527                                                 conf->gen.reset_scontext = context;
5528                                         }
5529                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5530                                         {
5531                                                 if (stack->source <= source)
5532                                                 {
5533                                                         stack->prior.val.realval = newval;
5534                                                         set_extra_field(&conf->gen, &stack->prior.extra,
5535                                                                                         newextra);
5536                                                         stack->source = source;
5537                                                         stack->scontext = context;
5538                                                 }
5539                                         }
5540                                 }
5541
5542                                 /* Perhaps we didn't install newextra anywhere */
5543                                 if (newextra && !extra_field_used(&conf->gen, newextra))
5544                                         free(newextra);
5545                                 break;
5546                         }
5547
5548                 case PGC_STRING:
5549                         {
5550                                 struct config_string *conf = (struct config_string *) record;
5551                                 char       *newval;
5552                                 void       *newextra = NULL;
5553
5554                                 if (value)
5555                                 {
5556                                         /*
5557                                          * The value passed by the caller could be transient, so
5558                                          * we always strdup it.
5559                                          */
5560                                         newval = guc_strdup(elevel, value);
5561                                         if (newval == NULL)
5562                                                 return 0;
5563
5564                                         /*
5565                                          * The only built-in "parsing" check we have is to apply
5566                                          * truncation if GUC_IS_NAME.
5567                                          */
5568                                         if (conf->gen.flags & GUC_IS_NAME)
5569                                                 truncate_identifier(newval, strlen(newval), true);
5570
5571                                         if (!call_string_check_hook(conf, &newval, &newextra,
5572                                                                                                 source, elevel))
5573                                         {
5574                                                 free(newval);
5575                                                 return 0;
5576                                         }
5577                                 }
5578                                 else if (source == PGC_S_DEFAULT)
5579                                 {
5580                                         /* non-NULL boot_val must always get strdup'd */
5581                                         if (conf->boot_val != NULL)
5582                                         {
5583                                                 newval = guc_strdup(elevel, conf->boot_val);
5584                                                 if (newval == NULL)
5585                                                         return 0;
5586                                         }
5587                                         else
5588                                                 newval = NULL;
5589
5590                                         if (!call_string_check_hook(conf, &newval, &newextra,
5591                                                                                                 source, elevel))
5592                                         {
5593                                                 free(newval);
5594                                                 return 0;
5595                                         }
5596                                 }
5597                                 else
5598                                 {
5599                                         /*
5600                                          * strdup not needed, since reset_val is already under
5601                                          * guc.c's control
5602                                          */
5603                                         newval = conf->reset_val;
5604                                         newextra = conf->reset_extra;
5605                                         source = conf->gen.reset_source;
5606                                         context = conf->gen.reset_scontext;
5607                                 }
5608
5609                                 if (prohibitValueChange)
5610                                 {
5611                                         /* newval shouldn't be NULL, so we're a bit sloppy here */
5612                                         if (*conf->variable == NULL || newval == NULL ||
5613                                                 strcmp(*conf->variable, newval) != 0)
5614                                         {
5615                                                 ereport(elevel,
5616                                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5617                                                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
5618                                                                                 name)));
5619                                                 return 0;
5620                                         }
5621                                         return -1;
5622                                 }
5623
5624                                 if (changeVal)
5625                                 {
5626                                         /* Save old value to support transaction abort */
5627                                         if (!makeDefault)
5628                                                 push_old_value(&conf->gen, action);
5629
5630                                         if (conf->assign_hook)
5631                                                 (*conf->assign_hook) (newval, newextra);
5632                                         set_string_field(conf, conf->variable, newval);
5633                                         set_extra_field(&conf->gen, &conf->gen.extra,
5634                                                                         newextra);
5635                                         conf->gen.source = source;
5636                                         conf->gen.scontext = context;
5637                                 }
5638
5639                                 if (makeDefault)
5640                                 {
5641                                         GucStack   *stack;
5642
5643                                         if (conf->gen.reset_source <= source)
5644                                         {
5645                                                 set_string_field(conf, &conf->reset_val, newval);
5646                                                 set_extra_field(&conf->gen, &conf->reset_extra,
5647                                                                                 newextra);
5648                                                 conf->gen.reset_source = source;
5649                                                 conf->gen.reset_scontext = context;
5650                                         }
5651                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5652                                         {
5653                                                 if (stack->source <= source)
5654                                                 {
5655                                                         set_string_field(conf, &stack->prior.val.stringval,
5656                                                                                          newval);
5657                                                         set_extra_field(&conf->gen, &stack->prior.extra,
5658                                                                                         newextra);
5659                                                         stack->source = source;
5660                                                         stack->scontext = context;
5661                                                 }
5662                                         }
5663                                 }
5664
5665                                 /* Perhaps we didn't install newval anywhere */
5666                                 if (newval && !string_field_used(conf, newval))
5667                                         free(newval);
5668                                 /* Perhaps we didn't install newextra anywhere */
5669                                 if (newextra && !extra_field_used(&conf->gen, newextra))
5670                                         free(newextra);
5671                                 break;
5672                         }
5673
5674                 case PGC_ENUM:
5675                         {
5676                                 struct config_enum *conf = (struct config_enum *) record;
5677                                 int                     newval;
5678                                 void       *newextra = NULL;
5679
5680                                 if (value)
5681                                 {
5682                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5683                                         {
5684                                                 char       *hintmsg;
5685
5686                                                 hintmsg = config_enum_get_options(conf,
5687                                                                                                                 "Available values: ",
5688                                                                                                                   ".", ", ");
5689
5690                                                 ereport(elevel,
5691                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5692                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5693                                                                 name, value),
5694                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5695
5696                                                 if (hintmsg)
5697                                                         pfree(hintmsg);
5698                                                 return 0;
5699                                         }
5700                                         if (!call_enum_check_hook(conf, &newval, &newextra,
5701                                                                                           source, elevel))
5702                                                 return 0;
5703                                 }
5704                                 else if (source == PGC_S_DEFAULT)
5705                                 {
5706                                         newval = conf->boot_val;
5707                                         if (!call_enum_check_hook(conf, &newval, &newextra,
5708                                                                                           source, elevel))
5709                                                 return 0;
5710                                 }
5711                                 else
5712                                 {
5713                                         newval = conf->reset_val;
5714                                         newextra = conf->reset_extra;
5715                                         source = conf->gen.reset_source;
5716                                         context = conf->gen.reset_scontext;
5717                                 }
5718
5719                                 if (prohibitValueChange)
5720                                 {
5721                                         if (*conf->variable != newval)
5722                                         {
5723                                                 ereport(elevel,
5724                                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
5725                                                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
5726                                                                                 name)));
5727                                                 return 0;
5728                                         }
5729                                         return -1;
5730                                 }
5731
5732                                 if (changeVal)
5733                                 {
5734                                         /* Save old value to support transaction abort */
5735                                         if (!makeDefault)
5736                                                 push_old_value(&conf->gen, action);
5737
5738                                         if (conf->assign_hook)
5739                                                 (*conf->assign_hook) (newval, newextra);
5740                                         *conf->variable = newval;
5741                                         set_extra_field(&conf->gen, &conf->gen.extra,
5742                                                                         newextra);
5743                                         conf->gen.source = source;
5744                                         conf->gen.scontext = context;
5745                                 }
5746                                 if (makeDefault)
5747                                 {
5748                                         GucStack   *stack;
5749
5750                                         if (conf->gen.reset_source <= source)
5751                                         {
5752                                                 conf->reset_val = newval;
5753                                                 set_extra_field(&conf->gen, &conf->reset_extra,
5754                                                                                 newextra);
5755                                                 conf->gen.reset_source = source;
5756                                                 conf->gen.reset_scontext = context;
5757                                         }
5758                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5759                                         {
5760                                                 if (stack->source <= source)
5761                                                 {
5762                                                         stack->prior.val.enumval = newval;
5763                                                         set_extra_field(&conf->gen, &stack->prior.extra,
5764                                                                                         newextra);
5765                                                         stack->source = source;
5766                                                         stack->scontext = context;
5767                                                 }
5768                                         }
5769                                 }
5770
5771                                 /* Perhaps we didn't install newextra anywhere */
5772                                 if (newextra && !extra_field_used(&conf->gen, newextra))
5773                                         free(newextra);
5774                                 break;
5775                         }
5776         }
5777
5778         if (changeVal && (record->flags & GUC_REPORT))
5779                 ReportGUCOption(record);
5780
5781         return changeVal ? 1 : -1;
5782 }
5783
5784
5785 /*
5786  * Set the fields for source file and line number the setting came from.
5787  */
5788 static void
5789 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5790 {
5791         struct config_generic *record;
5792         int                     elevel;
5793
5794         /*
5795          * To avoid cluttering the log, only the postmaster bleats loudly about
5796          * problems with the config file.
5797          */
5798         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5799
5800         record = find_option(name, true, elevel);
5801         /* should not happen */
5802         if (record == NULL)
5803                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5804
5805         sourcefile = guc_strdup(elevel, sourcefile);
5806         if (record->sourcefile)
5807                 free(record->sourcefile);
5808         record->sourcefile = sourcefile;
5809         record->sourceline = sourceline;
5810 }
5811
5812 /*
5813  * Set a config option to the given value.
5814  *
5815  * See also set_config_option; this is just the wrapper to be called from
5816  * outside GUC.  (This function should be used when possible, because its API
5817  * is more stable than set_config_option's.)
5818  *
5819  * Note: there is no support here for setting source file/line, as it
5820  * is currently not needed.
5821  */
5822 void
5823 SetConfigOption(const char *name, const char *value,
5824                                 GucContext context, GucSource source)
5825 {
5826         (void) set_config_option(name, value, context, source,
5827                                                          GUC_ACTION_SET, true, 0);
5828 }
5829
5830
5831
5832 /*
5833  * Fetch the current value of the option `name', as a string.
5834  *
5835  * If the option doesn't exist, return NULL if missing_ok is true (NOTE that
5836  * this cannot be distinguished from a string variable with a NULL value!),
5837  * otherwise throw an ereport and don't return.
5838  *
5839  * If restrict_superuser is true, we also enforce that only superusers can
5840  * see GUC_SUPERUSER_ONLY variables.  This should only be passed as true
5841  * in user-driven calls.
5842  *
5843  * The string is *not* allocated for modification and is really only
5844  * valid until the next call to configuration related functions.
5845  */
5846 const char *
5847 GetConfigOption(const char *name, bool missing_ok, bool restrict_superuser)
5848 {
5849         struct config_generic *record;
5850         static char buffer[256];
5851
5852         record = find_option(name, false, ERROR);
5853         if (record == NULL)
5854         {
5855                 if (missing_ok)
5856                         return NULL;
5857                 ereport(ERROR,
5858                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5859                                  errmsg("unrecognized configuration parameter \"%s\"",
5860                                                 name)));
5861         }
5862         if (restrict_superuser &&
5863                 (record->flags & GUC_SUPERUSER_ONLY) &&
5864                 !superuser())
5865                 ereport(ERROR,
5866                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5867                                  errmsg("must be superuser to examine \"%s\"", name)));
5868
5869         switch (record->vartype)
5870         {
5871                 case PGC_BOOL:
5872                         return *((struct config_bool *) record)->variable ? "on" : "off";
5873
5874                 case PGC_INT:
5875                         snprintf(buffer, sizeof(buffer), "%d",
5876                                          *((struct config_int *) record)->variable);
5877                         return buffer;
5878
5879                 case PGC_REAL:
5880                         snprintf(buffer, sizeof(buffer), "%g",
5881                                          *((struct config_real *) record)->variable);
5882                         return buffer;
5883
5884                 case PGC_STRING:
5885                         return *((struct config_string *) record)->variable;
5886
5887                 case PGC_ENUM:
5888                         return config_enum_lookup_by_value((struct config_enum *) record,
5889                                                                  *((struct config_enum *) record)->variable);
5890         }
5891         return NULL;
5892 }
5893
5894 /*
5895  * Get the RESET value associated with the given option.
5896  *
5897  * Note: this is not re-entrant, due to use of static result buffer;
5898  * not to mention that a string variable could have its reset_val changed.
5899  * Beware of assuming the result value is good for very long.
5900  */
5901 const char *
5902 GetConfigOptionResetString(const char *name)
5903 {
5904         struct config_generic *record;
5905         static char buffer[256];
5906
5907         record = find_option(name, false, ERROR);
5908         if (record == NULL)
5909                 ereport(ERROR,
5910                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5911                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5912         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5913                 ereport(ERROR,
5914                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5915                                  errmsg("must be superuser to examine \"%s\"", name)));
5916
5917         switch (record->vartype)
5918         {
5919                 case PGC_BOOL:
5920                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5921
5922                 case PGC_INT:
5923                         snprintf(buffer, sizeof(buffer), "%d",
5924                                          ((struct config_int *) record)->reset_val);
5925                         return buffer;
5926
5927                 case PGC_REAL:
5928                         snprintf(buffer, sizeof(buffer), "%g",
5929                                          ((struct config_real *) record)->reset_val);
5930                         return buffer;
5931
5932                 case PGC_STRING:
5933                         return ((struct config_string *) record)->reset_val;
5934
5935                 case PGC_ENUM:
5936                         return config_enum_lookup_by_value((struct config_enum *) record,
5937                                                                  ((struct config_enum *) record)->reset_val);
5938         }
5939         return NULL;
5940 }
5941
5942
5943 /*
5944  * flatten_set_variable_args
5945  *              Given a parsenode List as emitted by the grammar for SET,
5946  *              convert to the flat string representation used by GUC.
5947  *
5948  * We need to be told the name of the variable the args are for, because
5949  * the flattening rules vary (ugh).
5950  *
5951  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5952  * a palloc'd string.
5953  */
5954 static char *
5955 flatten_set_variable_args(const char *name, List *args)
5956 {
5957         struct config_generic *record;
5958         int                     flags;
5959         StringInfoData buf;
5960         ListCell   *l;
5961
5962         /* Fast path if just DEFAULT */
5963         if (args == NIL)
5964                 return NULL;
5965
5966         /*
5967          * Get flags for the variable; if it's not known, use default flags.
5968          * (Caller might throw error later, but not our business to do so here.)
5969          */
5970         record = find_option(name, false, WARNING);
5971         if (record)
5972                 flags = record->flags;
5973         else
5974                 flags = 0;
5975
5976         /* Complain if list input and non-list variable */
5977         if ((flags & GUC_LIST_INPUT) == 0 &&
5978                 list_length(args) != 1)
5979                 ereport(ERROR,
5980                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5981                                  errmsg("SET %s takes only one argument", name)));
5982
5983         initStringInfo(&buf);
5984
5985         /*
5986          * Each list member may be a plain A_Const node, or an A_Const within a
5987          * TypeCast; the latter case is supported only for ConstInterval arguments
5988          * (for SET TIME ZONE).
5989          */
5990         foreach(l, args)
5991         {
5992                 Node       *arg = (Node *) lfirst(l);
5993                 char       *val;
5994                 TypeName   *typeName = NULL;
5995                 A_Const    *con;
5996
5997                 if (l != list_head(args))
5998                         appendStringInfo(&buf, ", ");
5999
6000                 if (IsA(arg, TypeCast))
6001                 {
6002                         TypeCast   *tc = (TypeCast *) arg;
6003
6004                         arg = tc->arg;
6005                         typeName = tc->typeName;
6006                 }
6007
6008                 if (!IsA(arg, A_Const))
6009                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
6010                 con = (A_Const *) arg;
6011
6012                 switch (nodeTag(&con->val))
6013                 {
6014                         case T_Integer:
6015                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
6016                                 break;
6017                         case T_Float:
6018                                 /* represented as a string, so just copy it */
6019                                 appendStringInfoString(&buf, strVal(&con->val));
6020                                 break;
6021                         case T_String:
6022                                 val = strVal(&con->val);
6023                                 if (typeName != NULL)
6024                                 {
6025                                         /*
6026                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
6027                                          * to interval and back to normalize the value and account
6028                                          * for any typmod.
6029                                          */
6030                                         Oid                     typoid;
6031                                         int32           typmod;
6032                                         Datum           interval;
6033                                         char       *intervalout;
6034
6035                                         typenameTypeIdAndMod(NULL, typeName, &typoid, &typmod);
6036                                         Assert(typoid == INTERVALOID);
6037
6038                                         interval =
6039                                                 DirectFunctionCall3(interval_in,
6040                                                                                         CStringGetDatum(val),
6041                                                                                         ObjectIdGetDatum(InvalidOid),
6042                                                                                         Int32GetDatum(typmod));
6043
6044                                         intervalout =
6045                                                 DatumGetCString(DirectFunctionCall1(interval_out,
6046                                                                                                                         interval));
6047                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
6048                                 }
6049                                 else
6050                                 {
6051                                         /*
6052                                          * Plain string literal or identifier.  For quote mode,
6053                                          * quote it if it's not a vanilla identifier.
6054                                          */
6055                                         if (flags & GUC_LIST_QUOTE)
6056                                                 appendStringInfoString(&buf, quote_identifier(val));
6057                                         else
6058                                                 appendStringInfoString(&buf, val);
6059                                 }
6060                                 break;
6061                         default:
6062                                 elog(ERROR, "unrecognized node type: %d",
6063                                          (int) nodeTag(&con->val));
6064                                 break;
6065                 }
6066         }
6067
6068         return buf.data;
6069 }
6070
6071
6072 /*
6073  * SET command
6074  */
6075 void
6076 ExecSetVariableStmt(VariableSetStmt *stmt)
6077 {
6078         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
6079
6080         switch (stmt->kind)
6081         {
6082                 case VAR_SET_VALUE:
6083                 case VAR_SET_CURRENT:
6084                         (void) set_config_option(stmt->name,
6085                                                                          ExtractSetVariableArgs(stmt),
6086                                                                          (superuser() ? PGC_SUSET : PGC_USERSET),
6087                                                                          PGC_S_SESSION,
6088                                                                          action,
6089                                                                          true,
6090                                                                          0);
6091                         break;
6092                 case VAR_SET_MULTI:
6093
6094                         /*
6095                          * Special case for special SQL syntax that effectively sets more
6096                          * than one variable per statement.
6097                          */
6098                         if (strcmp(stmt->name, "TRANSACTION") == 0)
6099                         {
6100                                 ListCell   *head;
6101
6102                                 foreach(head, stmt->args)
6103                                 {
6104                                         DefElem    *item = (DefElem *) lfirst(head);
6105
6106                                         if (strcmp(item->defname, "transaction_isolation") == 0)
6107                                                 SetPGVariable("transaction_isolation",
6108                                                                           list_make1(item->arg), stmt->is_local);
6109                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
6110                                                 SetPGVariable("transaction_read_only",
6111                                                                           list_make1(item->arg), stmt->is_local);
6112                                         else if (strcmp(item->defname, "transaction_deferrable") == 0)
6113                                                 SetPGVariable("transaction_deferrable",
6114                                                                           list_make1(item->arg), stmt->is_local);
6115                                         else
6116                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
6117                                                          item->defname);
6118                                 }
6119                         }
6120                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
6121                         {
6122                                 ListCell   *head;
6123
6124                                 foreach(head, stmt->args)
6125                                 {
6126                                         DefElem    *item = (DefElem *) lfirst(head);
6127
6128                                         if (strcmp(item->defname, "transaction_isolation") == 0)
6129                                                 SetPGVariable("default_transaction_isolation",
6130                                                                           list_make1(item->arg), stmt->is_local);
6131                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
6132                                                 SetPGVariable("default_transaction_read_only",
6133                                                                           list_make1(item->arg), stmt->is_local);
6134                                         else if (strcmp(item->defname, "transaction_deferrable") == 0)
6135                                                 SetPGVariable("default_transaction_deferrable",
6136                                                                           list_make1(item->arg), stmt->is_local);
6137                                         else
6138                                                 elog(ERROR, "unexpected SET SESSION element: %s",
6139                                                          item->defname);
6140                                 }
6141                         }
6142                         else
6143                                 elog(ERROR, "unexpected SET MULTI element: %s",
6144                                          stmt->name);
6145                         break;
6146                 case VAR_SET_DEFAULT:
6147                 case VAR_RESET:
6148                         (void) set_config_option(stmt->name,
6149                                                                          NULL,
6150                                                                          (superuser() ? PGC_SUSET : PGC_USERSET),
6151                                                                          PGC_S_SESSION,
6152                                                                          action,
6153                                                                          true,
6154                                                                          0);
6155                         break;
6156                 case VAR_RESET_ALL:
6157                         ResetAllOptions();
6158                         break;
6159         }
6160 }
6161
6162 /*
6163  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
6164  * The result is palloc'd.
6165  *
6166  * This is exported for use by actions such as ALTER ROLE SET.
6167  */
6168 char *
6169 ExtractSetVariableArgs(VariableSetStmt *stmt)
6170 {
6171         switch (stmt->kind)
6172         {
6173                 case VAR_SET_VALUE:
6174                         return flatten_set_variable_args(stmt->name, stmt->args);
6175                 case VAR_SET_CURRENT:
6176                         return GetConfigOptionByName(stmt->name, NULL);
6177                 default:
6178                         return NULL;
6179         }
6180 }
6181
6182 /*
6183  * SetPGVariable - SET command exported as an easily-C-callable function.
6184  *
6185  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
6186  * by passing args == NIL), but not SET FROM CURRENT functionality.
6187  */
6188 void
6189 SetPGVariable(const char *name, List *args, bool is_local)
6190 {
6191         char       *argstring = flatten_set_variable_args(name, args);
6192
6193         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
6194         (void) set_config_option(name,
6195                                                          argstring,
6196                                                          (superuser() ? PGC_SUSET : PGC_USERSET),
6197                                                          PGC_S_SESSION,
6198                                                          is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
6199                                                          true,
6200                                                          0);
6201 }
6202
6203 /*
6204  * SET command wrapped as a SQL callable function.
6205  */
6206 Datum
6207 set_config_by_name(PG_FUNCTION_ARGS)
6208 {
6209         char       *name;
6210         char       *value;
6211         char       *new_value;
6212         bool            is_local;
6213
6214         if (PG_ARGISNULL(0))
6215                 ereport(ERROR,
6216                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
6217                                  errmsg("SET requires parameter name")));
6218
6219         /* Get the GUC variable name */
6220         name = TextDatumGetCString(PG_GETARG_DATUM(0));
6221
6222         /* Get the desired value or set to NULL for a reset request */
6223         if (PG_ARGISNULL(1))
6224                 value = NULL;
6225         else
6226                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
6227
6228         /*
6229          * Get the desired state of is_local. Default to false if provided value
6230          * is NULL
6231          */
6232         if (PG_ARGISNULL(2))
6233                 is_local = false;
6234         else
6235                 is_local = PG_GETARG_BOOL(2);
6236
6237         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
6238         (void) set_config_option(name,
6239                                                          value,
6240                                                          (superuser() ? PGC_SUSET : PGC_USERSET),
6241                                                          PGC_S_SESSION,
6242                                                          is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
6243                                                          true,
6244                                                          0);
6245
6246         /* get the new current value */
6247         new_value = GetConfigOptionByName(name, NULL);
6248
6249         /* Convert return string to text */
6250         PG_RETURN_TEXT_P(cstring_to_text(new_value));
6251 }
6252
6253
6254 /*
6255  * Common code for DefineCustomXXXVariable subroutines: allocate the
6256  * new variable's config struct and fill in generic fields.
6257  */
6258 static struct config_generic *
6259 init_custom_variable(const char *name,
6260                                          const char *short_desc,
6261                                          const char *long_desc,
6262                                          GucContext context,
6263                                          int flags,
6264                                          enum config_type type,
6265                                          size_t sz)
6266 {
6267         struct config_generic *gen;
6268
6269         /*
6270          * Only allow custom PGC_POSTMASTER variables to be created during shared
6271          * library preload; any later than that, we can't ensure that the value
6272          * doesn't change after startup.  This is a fatal elog if it happens; just
6273          * erroring out isn't safe because we don't know what the calling loadable
6274          * module might already have hooked into.
6275          */
6276         if (context == PGC_POSTMASTER &&
6277                 !process_shared_preload_libraries_in_progress)
6278                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
6279
6280         gen = (struct config_generic *) guc_malloc(ERROR, sz);
6281         memset(gen, 0, sz);
6282
6283         gen->name = guc_strdup(ERROR, name);
6284         gen->context = context;
6285         gen->group = CUSTOM_OPTIONS;
6286         gen->short_desc = short_desc;
6287         gen->long_desc = long_desc;
6288         gen->flags = flags;
6289         gen->vartype = type;
6290
6291         return gen;
6292 }
6293
6294 /*
6295  * Common code for DefineCustomXXXVariable subroutines: insert the new
6296  * variable into the GUC variable array, replacing any placeholder.
6297  */
6298 static void
6299 define_custom_variable(struct config_generic * variable)
6300 {
6301         const char *name = variable->name;
6302         const char **nameAddr = &name;
6303         struct config_string *pHolder;
6304         struct config_generic **res;
6305
6306         /*
6307          * See if there's a placeholder by the same name.
6308          */
6309         res = (struct config_generic **) bsearch((void *) &nameAddr,
6310                                                                                          (void *) guc_variables,
6311                                                                                          num_guc_variables,
6312                                                                                          sizeof(struct config_generic *),
6313                                                                                          guc_var_compare);
6314         if (res == NULL)
6315         {
6316                 /*
6317                  * No placeholder to replace, so we can just add it ... but first,
6318                  * make sure it's initialized to its default value.
6319                  */
6320                 InitializeOneGUCOption(variable);
6321                 add_guc_variable(variable, ERROR);
6322                 return;
6323         }
6324
6325         /*
6326          * This better be a placeholder
6327          */
6328         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
6329                 ereport(ERROR,
6330                                 (errcode(ERRCODE_INTERNAL_ERROR),
6331                                  errmsg("attempt to redefine parameter \"%s\"", name)));
6332
6333         Assert((*res)->vartype == PGC_STRING);
6334         pHolder = (struct config_string *) (*res);
6335
6336         /*
6337          * First, set the variable to its default value.  We must do this even
6338          * though we intend to immediately apply a new value, since it's possible
6339          * that the new value is invalid.
6340          */
6341         InitializeOneGUCOption(variable);
6342
6343         /*
6344          * Replace the placeholder. We aren't changing the name, so no re-sorting
6345          * is necessary
6346          */
6347         *res = variable;
6348
6349         /*
6350          * Assign the string value(s) stored in the placeholder to the real
6351          * variable.  Essentially, we need to duplicate all the active and stacked
6352          * values, but with appropriate validation and datatype adjustment.
6353          *
6354          * If an assignment fails, we report a WARNING and keep going.  We don't
6355          * want to throw ERROR for bad values, because it'd bollix the add-on
6356          * module that's presumably halfway through getting loaded.  In such cases
6357          * the default or previous state will become active instead.
6358          */
6359
6360         /* First, apply the reset value if any */
6361         if (pHolder->reset_val)
6362                 (void) set_config_option(name, pHolder->reset_val,
6363                                                                  pHolder->gen.reset_scontext,
6364                                                                  pHolder->gen.reset_source,
6365                                                                  GUC_ACTION_SET, true, WARNING);
6366         /* That should not have resulted in stacking anything */
6367         Assert(variable->stack == NULL);
6368
6369         /* Now, apply current and stacked values, in the order they were stacked */
6370         reapply_stacked_values(variable, pHolder, pHolder->gen.stack,
6371                                                    *(pHolder->variable),
6372                                                    pHolder->gen.scontext, pHolder->gen.source);
6373
6374         /* Also copy over any saved source-location information */
6375         if (pHolder->gen.sourcefile)
6376                 set_config_sourcefile(name, pHolder->gen.sourcefile,
6377                                                           pHolder->gen.sourceline);
6378
6379         /*
6380          * Free up as much as we conveniently can of the placeholder structure.
6381          * (This neglects any stack items, so it's possible for some memory to be
6382          * leaked.  Since this can only happen once per session per variable, it
6383          * doesn't seem worth spending much code on.)
6384          */
6385         set_string_field(pHolder, pHolder->variable, NULL);
6386         set_string_field(pHolder, &pHolder->reset_val, NULL);
6387
6388         free(pHolder);
6389 }
6390
6391 /*
6392  * Recursive subroutine for define_custom_variable: reapply non-reset values
6393  *
6394  * We recurse so that the values are applied in the same order as originally.
6395  * At each recursion level, apply the upper-level value (passed in) in the
6396  * fashion implied by the stack entry.
6397  */
6398 static void
6399 reapply_stacked_values(struct config_generic * variable,
6400                                            struct config_string *pHolder,
6401                                            GucStack *stack,
6402                                            const char *curvalue,
6403                                            GucContext curscontext, GucSource cursource)
6404 {
6405         const char *name = variable->name;
6406         GucStack   *oldvarstack = variable->stack;
6407
6408         if (stack != NULL)
6409         {
6410                 /* First, recurse, so that stack items are processed bottom to top */
6411                 reapply_stacked_values(variable, pHolder, stack->prev,
6412                                                            stack->prior.val.stringval,
6413                                                            stack->scontext, stack->source);
6414
6415                 /* See how to apply the passed-in value */
6416                 switch (stack->state)
6417                 {
6418                         case GUC_SAVE:
6419                                 (void) set_config_option(name, curvalue,
6420                                                                                  curscontext, cursource,
6421                                                                                  GUC_ACTION_SAVE, true, WARNING);
6422                                 break;
6423
6424                         case GUC_SET:
6425                                 (void) set_config_option(name, curvalue,
6426                                                                                  curscontext, cursource,
6427                                                                                  GUC_ACTION_SET, true, WARNING);
6428                                 break;
6429
6430                         case GUC_LOCAL:
6431                                 (void) set_config_option(name, curvalue,
6432                                                                                  curscontext, cursource,
6433                                                                                  GUC_ACTION_LOCAL, true, WARNING);
6434                                 break;
6435
6436                         case GUC_SET_LOCAL:
6437                                 /* first, apply the masked value as SET */
6438                                 (void) set_config_option(name, stack->masked.val.stringval,
6439                                                                                  stack->masked_scontext, PGC_S_SESSION,
6440                                                                                  GUC_ACTION_SET, true, WARNING);
6441                                 /* then apply the current value as LOCAL */
6442                                 (void) set_config_option(name, curvalue,
6443                                                                                  curscontext, cursource,
6444                                                                                  GUC_ACTION_LOCAL, true, WARNING);
6445                                 break;
6446                 }
6447
6448                 /* If we successfully made a stack entry, adjust its nest level */
6449                 if (variable->stack != oldvarstack)
6450                         variable->stack->nest_level = stack->nest_level;
6451         }
6452         else
6453         {
6454                 /*
6455                  * We are at the end of the stack.  If the active/previous value is
6456                  * different from the reset value, it must represent a previously
6457                  * committed session value.  Apply it, and then drop the stack entry
6458                  * that set_config_option will have created under the impression that
6459                  * this is to be just a transactional assignment.  (We leak the stack
6460                  * entry.)
6461                  */
6462                 if (curvalue != pHolder->reset_val ||
6463                         curscontext != pHolder->gen.reset_scontext ||
6464                         cursource != pHolder->gen.reset_source)
6465                 {
6466                         (void) set_config_option(name, curvalue,
6467                                                                          curscontext, cursource,
6468                                                                          GUC_ACTION_SET, true, WARNING);
6469                         variable->stack = NULL;
6470                 }
6471         }
6472 }
6473
6474 void
6475 DefineCustomBoolVariable(const char *name,
6476                                                  const char *short_desc,
6477                                                  const char *long_desc,
6478                                                  bool *valueAddr,
6479                                                  bool bootValue,
6480                                                  GucContext context,
6481                                                  int flags,
6482                                                  GucBoolCheckHook check_hook,
6483                                                  GucBoolAssignHook assign_hook,
6484                                                  GucShowHook show_hook)
6485 {
6486         struct config_bool *var;
6487
6488         var = (struct config_bool *)
6489                 init_custom_variable(name, short_desc, long_desc, context, flags,
6490                                                          PGC_BOOL, sizeof(struct config_bool));
6491         var->variable = valueAddr;
6492         var->boot_val = bootValue;
6493         var->reset_val = bootValue;
6494         var->check_hook = check_hook;
6495         var->assign_hook = assign_hook;
6496         var->show_hook = show_hook;
6497         define_custom_variable(&var->gen);
6498 }
6499
6500 void
6501 DefineCustomIntVariable(const char *name,
6502                                                 const char *short_desc,
6503                                                 const char *long_desc,
6504                                                 int *valueAddr,
6505                                                 int bootValue,
6506                                                 int minValue,
6507                                                 int maxValue,
6508                                                 GucContext context,
6509                                                 int flags,
6510                                                 GucIntCheckHook check_hook,
6511                                                 GucIntAssignHook assign_hook,
6512                                                 GucShowHook show_hook)
6513 {
6514         struct config_int *var;
6515
6516         var = (struct config_int *)
6517                 init_custom_variable(name, short_desc, long_desc, context, flags,
6518                                                          PGC_INT, sizeof(struct config_int));
6519         var->variable = valueAddr;
6520         var->boot_val = bootValue;
6521         var->reset_val = bootValue;
6522         var->min = minValue;
6523         var->max = maxValue;
6524         var->check_hook = check_hook;
6525         var->assign_hook = assign_hook;
6526         var->show_hook = show_hook;
6527         define_custom_variable(&var->gen);
6528 }
6529
6530 void
6531 DefineCustomRealVariable(const char *name,
6532                                                  const char *short_desc,
6533                                                  const char *long_desc,
6534                                                  double *valueAddr,
6535                                                  double bootValue,
6536                                                  double minValue,
6537                                                  double maxValue,
6538                                                  GucContext context,
6539                                                  int flags,
6540                                                  GucRealCheckHook check_hook,
6541                                                  GucRealAssignHook assign_hook,
6542                                                  GucShowHook show_hook)
6543 {
6544         struct config_real *var;
6545
6546         var = (struct config_real *)
6547                 init_custom_variable(name, short_desc, long_desc, context, flags,
6548                                                          PGC_REAL, sizeof(struct config_real));
6549         var->variable = valueAddr;
6550         var->boot_val = bootValue;
6551         var->reset_val = bootValue;
6552         var->min = minValue;
6553         var->max = maxValue;
6554         var->check_hook = check_hook;
6555         var->assign_hook = assign_hook;
6556         var->show_hook = show_hook;
6557         define_custom_variable(&var->gen);
6558 }
6559
6560 void
6561 DefineCustomStringVariable(const char *name,
6562                                                    const char *short_desc,
6563                                                    const char *long_desc,
6564                                                    char **valueAddr,
6565                                                    const char *bootValue,
6566                                                    GucContext context,
6567                                                    int flags,
6568                                                    GucStringCheckHook check_hook,
6569                                                    GucStringAssignHook assign_hook,
6570                                                    GucShowHook show_hook)
6571 {
6572         struct config_string *var;
6573
6574         var = (struct config_string *)
6575                 init_custom_variable(name, short_desc, long_desc, context, flags,
6576                                                          PGC_STRING, sizeof(struct config_string));
6577         var->variable = valueAddr;
6578         var->boot_val = bootValue;
6579         var->check_hook = check_hook;
6580         var->assign_hook = assign_hook;
6581         var->show_hook = show_hook;
6582         define_custom_variable(&var->gen);
6583 }
6584
6585 void
6586 DefineCustomEnumVariable(const char *name,
6587                                                  const char *short_desc,
6588                                                  const char *long_desc,
6589                                                  int *valueAddr,
6590                                                  int bootValue,
6591                                                  const struct config_enum_entry * options,
6592                                                  GucContext context,
6593                                                  int flags,
6594                                                  GucEnumCheckHook check_hook,
6595                                                  GucEnumAssignHook assign_hook,
6596                                                  GucShowHook show_hook)
6597 {
6598         struct config_enum *var;
6599
6600         var = (struct config_enum *)
6601                 init_custom_variable(name, short_desc, long_desc, context, flags,
6602                                                          PGC_ENUM, sizeof(struct config_enum));
6603         var->variable = valueAddr;
6604         var->boot_val = bootValue;
6605         var->reset_val = bootValue;
6606         var->options = options;
6607         var->check_hook = check_hook;
6608         var->assign_hook = assign_hook;
6609         var->show_hook = show_hook;
6610         define_custom_variable(&var->gen);
6611 }
6612
6613 void
6614 EmitWarningsOnPlaceholders(const char *className)
6615 {
6616         int                     classLen = strlen(className);
6617         int                     i;
6618
6619         for (i = 0; i < num_guc_variables; i++)
6620         {
6621                 struct config_generic *var = guc_variables[i];
6622
6623                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
6624                         strncmp(className, var->name, classLen) == 0 &&
6625                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
6626                 {
6627                         ereport(WARNING,
6628                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
6629                                          errmsg("unrecognized configuration parameter \"%s\"",
6630                                                         var->name)));
6631                 }
6632         }
6633 }
6634
6635
6636 /*
6637  * SHOW command
6638  */
6639 void
6640 GetPGVariable(const char *name, DestReceiver *dest)
6641 {
6642         if (guc_name_compare(name, "all") == 0)
6643                 ShowAllGUCConfig(dest);
6644         else
6645                 ShowGUCConfigOption(name, dest);
6646 }
6647
6648 TupleDesc
6649 GetPGVariableResultDesc(const char *name)
6650 {
6651         TupleDesc       tupdesc;
6652
6653         if (guc_name_compare(name, "all") == 0)
6654         {
6655                 /* need a tuple descriptor representing three TEXT columns */
6656                 tupdesc = CreateTemplateTupleDesc(3, false);
6657                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6658                                                    TEXTOID, -1, 0);
6659                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6660                                                    TEXTOID, -1, 0);
6661                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6662                                                    TEXTOID, -1, 0);
6663         }
6664         else
6665         {
6666                 const char *varname;
6667
6668                 /* Get the canonical spelling of name */
6669                 (void) GetConfigOptionByName(name, &varname);
6670
6671                 /* need a tuple descriptor representing a single TEXT column */
6672                 tupdesc = CreateTemplateTupleDesc(1, false);
6673                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
6674                                                    TEXTOID, -1, 0);
6675         }
6676         return tupdesc;
6677 }
6678
6679
6680 /*
6681  * SHOW command
6682  */
6683 static void
6684 ShowGUCConfigOption(const char *name, DestReceiver *dest)
6685 {
6686         TupOutputState *tstate;
6687         TupleDesc       tupdesc;
6688         const char *varname;
6689         char       *value;
6690
6691         /* Get the value and canonical spelling of name */
6692         value = GetConfigOptionByName(name, &varname);
6693
6694         /* need a tuple descriptor representing a single TEXT column */
6695         tupdesc = CreateTemplateTupleDesc(1, false);
6696         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
6697                                            TEXTOID, -1, 0);
6698
6699         /* prepare for projection of tuples */
6700         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6701
6702         /* Send it */
6703         do_text_output_oneline(tstate, value);
6704
6705         end_tup_output(tstate);
6706 }
6707
6708 /*
6709  * SHOW ALL command
6710  */
6711 static void
6712 ShowAllGUCConfig(DestReceiver *dest)
6713 {
6714         bool            am_superuser = superuser();
6715         int                     i;
6716         TupOutputState *tstate;
6717         TupleDesc       tupdesc;
6718         Datum           values[3];
6719         bool            isnull[3] = {false, false, false};
6720
6721         /* need a tuple descriptor representing three TEXT columns */
6722         tupdesc = CreateTemplateTupleDesc(3, false);
6723         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6724                                            TEXTOID, -1, 0);
6725         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6726                                            TEXTOID, -1, 0);
6727         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6728                                            TEXTOID, -1, 0);
6729
6730         /* prepare for projection of tuples */
6731         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6732
6733         for (i = 0; i < num_guc_variables; i++)
6734         {
6735                 struct config_generic *conf = guc_variables[i];
6736                 char       *setting;
6737
6738                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6739                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6740                         continue;
6741
6742                 /* assign to the values array */
6743                 values[0] = PointerGetDatum(cstring_to_text(conf->name));
6744
6745                 setting = _ShowOption(conf, true);
6746                 if (setting)
6747                 {
6748                         values[1] = PointerGetDatum(cstring_to_text(setting));
6749                         isnull[1] = false;
6750                 }
6751                 else
6752                 {
6753                         values[1] = PointerGetDatum(NULL);
6754                         isnull[1] = true;
6755                 }
6756
6757                 values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
6758
6759                 /* send it to dest */
6760                 do_tup_output(tstate, values, isnull);
6761
6762                 /* clean up */
6763                 pfree(DatumGetPointer(values[0]));
6764                 if (setting)
6765                 {
6766                         pfree(setting);
6767                         pfree(DatumGetPointer(values[1]));
6768                 }
6769                 pfree(DatumGetPointer(values[2]));
6770         }
6771
6772         end_tup_output(tstate);
6773 }
6774
6775 /*
6776  * Return GUC variable value by name; optionally return canonical
6777  * form of name.  Return value is palloc'd.
6778  */
6779 char *
6780 GetConfigOptionByName(const char *name, const char **varname)
6781 {
6782         struct config_generic *record;
6783
6784         record = find_option(name, false, ERROR);
6785         if (record == NULL)
6786                 ereport(ERROR,
6787                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6788                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6789         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6790                 ereport(ERROR,
6791                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6792                                  errmsg("must be superuser to examine \"%s\"", name)));
6793
6794         if (varname)
6795                 *varname = record->name;
6796
6797         return _ShowOption(record, true);
6798 }
6799
6800 /*
6801  * Return GUC variable value by variable number; optionally return canonical
6802  * form of name.  Return value is palloc'd.
6803  */
6804 void
6805 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6806 {
6807         char            buffer[256];
6808         struct config_generic *conf;
6809
6810         /* check requested variable number valid */
6811         Assert((varnum >= 0) && (varnum < num_guc_variables));
6812
6813         conf = guc_variables[varnum];
6814
6815         if (noshow)
6816         {
6817                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6818                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6819                         *noshow = true;
6820                 else
6821                         *noshow = false;
6822         }
6823
6824         /* first get the generic attributes */
6825
6826         /* name */
6827         values[0] = conf->name;
6828
6829         /* setting : use _ShowOption in order to avoid duplicating the logic */
6830         values[1] = _ShowOption(conf, false);
6831
6832         /* unit */
6833         if (conf->vartype == PGC_INT)
6834         {
6835                 static char buf[8];
6836
6837                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6838                 {
6839                         case GUC_UNIT_KB:
6840                                 values[2] = "kB";
6841                                 break;
6842                         case GUC_UNIT_BLOCKS:
6843                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6844                                 values[2] = buf;
6845                                 break;
6846                         case GUC_UNIT_XBLOCKS:
6847                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6848                                 values[2] = buf;
6849                                 break;
6850                         case GUC_UNIT_MS:
6851                                 values[2] = "ms";
6852                                 break;
6853                         case GUC_UNIT_S:
6854                                 values[2] = "s";
6855                                 break;
6856                         case GUC_UNIT_MIN:
6857                                 values[2] = "min";
6858                                 break;
6859                         default:
6860                                 values[2] = "";
6861                                 break;
6862                 }
6863         }
6864         else
6865                 values[2] = NULL;
6866
6867         /* group */
6868         values[3] = config_group_names[conf->group];
6869
6870         /* short_desc */
6871         values[4] = conf->short_desc;
6872
6873         /* extra_desc */
6874         values[5] = conf->long_desc;
6875
6876         /* context */
6877         values[6] = GucContext_Names[conf->context];
6878
6879         /* vartype */
6880         values[7] = config_type_names[conf->vartype];
6881
6882         /* source */
6883         values[8] = GucSource_Names[conf->source];
6884
6885         /* now get the type specifc attributes */
6886         switch (conf->vartype)
6887         {
6888                 case PGC_BOOL:
6889                         {
6890                                 struct config_bool *lconf = (struct config_bool *) conf;
6891
6892                                 /* min_val */
6893                                 values[9] = NULL;
6894
6895                                 /* max_val */
6896                                 values[10] = NULL;
6897
6898                                 /* enumvals */
6899                                 values[11] = NULL;
6900
6901                                 /* boot_val */
6902                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6903
6904                                 /* reset_val */
6905                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6906                         }
6907                         break;
6908
6909                 case PGC_INT:
6910                         {
6911                                 struct config_int *lconf = (struct config_int *) conf;
6912
6913                                 /* min_val */
6914                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6915                                 values[9] = pstrdup(buffer);
6916
6917                                 /* max_val */
6918                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6919                                 values[10] = pstrdup(buffer);
6920
6921                                 /* enumvals */
6922                                 values[11] = NULL;
6923
6924                                 /* boot_val */
6925                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6926                                 values[12] = pstrdup(buffer);
6927
6928                                 /* reset_val */
6929                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6930                                 values[13] = pstrdup(buffer);
6931                         }
6932                         break;
6933
6934                 case PGC_REAL:
6935                         {
6936                                 struct config_real *lconf = (struct config_real *) conf;
6937
6938                                 /* min_val */
6939                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6940                                 values[9] = pstrdup(buffer);
6941
6942                                 /* max_val */
6943                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6944                                 values[10] = pstrdup(buffer);
6945
6946                                 /* enumvals */
6947                                 values[11] = NULL;
6948
6949                                 /* boot_val */
6950                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6951                                 values[12] = pstrdup(buffer);
6952
6953                                 /* reset_val */
6954                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6955                                 values[13] = pstrdup(buffer);
6956                         }
6957                         break;
6958
6959                 case PGC_STRING:
6960                         {
6961                                 struct config_string *lconf = (struct config_string *) conf;
6962
6963                                 /* min_val */
6964                                 values[9] = NULL;
6965
6966                                 /* max_val */
6967                                 values[10] = NULL;
6968
6969                                 /* enumvals */
6970                                 values[11] = NULL;
6971
6972                                 /* boot_val */
6973                                 if (lconf->boot_val == NULL)
6974                                         values[12] = NULL;
6975                                 else
6976                                         values[12] = pstrdup(lconf->boot_val);
6977
6978                                 /* reset_val */
6979                                 if (lconf->reset_val == NULL)
6980                                         values[13] = NULL;
6981                                 else
6982                                         values[13] = pstrdup(lconf->reset_val);
6983                         }
6984                         break;
6985
6986                 case PGC_ENUM:
6987                         {
6988                                 struct config_enum *lconf = (struct config_enum *) conf;
6989
6990                                 /* min_val */
6991                                 values[9] = NULL;
6992
6993                                 /* max_val */
6994                                 values[10] = NULL;
6995
6996                                 /* enumvals */
6997
6998                                 /*
6999                                  * NOTE! enumvals with double quotes in them are not
7000                                  * supported!
7001                                  */
7002                                 values[11] = config_enum_get_options((struct config_enum *) conf,
7003                                                                                                          "{\"", "\"}", "\",\"");
7004
7005                                 /* boot_val */
7006                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
7007                                                                                                                    lconf->boot_val));
7008
7009                                 /* reset_val */
7010                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
7011                                                                                                                   lconf->reset_val));
7012                         }
7013                         break;
7014
7015                 default:
7016                         {
7017                                 /*
7018                                  * should never get here, but in case we do, set 'em to NULL
7019                                  */
7020
7021                                 /* min_val */
7022                                 values[9] = NULL;
7023
7024                                 /* max_val */
7025                                 values[10] = NULL;
7026
7027                                 /* enumvals */
7028                                 values[11] = NULL;
7029
7030                                 /* boot_val */
7031                                 values[12] = NULL;
7032
7033                                 /* reset_val */
7034                                 values[13] = NULL;
7035                         }
7036                         break;
7037         }
7038
7039         /*
7040          * If the setting came from a config file, set the source location. For
7041          * security reasons, we don't show source file/line number for
7042          * non-superusers.
7043          */
7044         if (conf->source == PGC_S_FILE && superuser())
7045         {
7046                 values[14] = conf->sourcefile;
7047                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
7048                 values[15] = pstrdup(buffer);
7049         }
7050         else
7051         {
7052                 values[14] = NULL;
7053                 values[15] = NULL;
7054         }
7055 }
7056
7057 /*
7058  * Return the total number of GUC variables
7059  */
7060 int
7061 GetNumConfigOptions(void)
7062 {
7063         return num_guc_variables;
7064 }
7065
7066 /*
7067  * show_config_by_name - equiv to SHOW X command but implemented as
7068  * a function.
7069  */
7070 Datum
7071 show_config_by_name(PG_FUNCTION_ARGS)
7072 {
7073         char       *varname;
7074         char       *varval;
7075
7076         /* Get the GUC variable name */
7077         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
7078
7079         /* Get the value */
7080         varval = GetConfigOptionByName(varname, NULL);
7081
7082         /* Convert to text */
7083         PG_RETURN_TEXT_P(cstring_to_text(varval));
7084 }
7085
7086 /*
7087  * show_all_settings - equiv to SHOW ALL command but implemented as
7088  * a Table Function.
7089  */
7090 #define NUM_PG_SETTINGS_ATTS    16
7091
7092 Datum
7093 show_all_settings(PG_FUNCTION_ARGS)
7094 {
7095         FuncCallContext *funcctx;
7096         TupleDesc       tupdesc;
7097         int                     call_cntr;
7098         int                     max_calls;
7099         AttInMetadata *attinmeta;
7100         MemoryContext oldcontext;
7101
7102         /* stuff done only on the first call of the function */
7103         if (SRF_IS_FIRSTCALL())
7104         {
7105                 /* create a function context for cross-call persistence */
7106                 funcctx = SRF_FIRSTCALL_INIT();
7107
7108                 /*
7109                  * switch to memory context appropriate for multiple function calls
7110                  */
7111                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
7112
7113                 /*
7114                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
7115                  * of the appropriate types
7116                  */
7117                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
7118                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
7119                                                    TEXTOID, -1, 0);
7120                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
7121                                                    TEXTOID, -1, 0);
7122                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
7123                                                    TEXTOID, -1, 0);
7124                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
7125                                                    TEXTOID, -1, 0);
7126                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
7127                                                    TEXTOID, -1, 0);
7128                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
7129                                                    TEXTOID, -1, 0);
7130                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
7131                                                    TEXTOID, -1, 0);
7132                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
7133                                                    TEXTOID, -1, 0);
7134                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
7135                                                    TEXTOID, -1, 0);
7136                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
7137                                                    TEXTOID, -1, 0);
7138                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
7139                                                    TEXTOID, -1, 0);
7140                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
7141                                                    TEXTARRAYOID, -1, 0);
7142                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
7143                                                    TEXTOID, -1, 0);
7144                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
7145                                                    TEXTOID, -1, 0);
7146                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
7147                                                    TEXTOID, -1, 0);
7148                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
7149                                                    INT4OID, -1, 0);
7150
7151                 /*
7152                  * Generate attribute metadata needed later to produce tuples from raw
7153                  * C strings
7154                  */
7155                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
7156                 funcctx->attinmeta = attinmeta;
7157
7158                 /* total number of tuples to be returned */
7159                 funcctx->max_calls = GetNumConfigOptions();
7160
7161                 MemoryContextSwitchTo(oldcontext);
7162         }
7163
7164         /* stuff done on every call of the function */
7165         funcctx = SRF_PERCALL_SETUP();
7166
7167         call_cntr = funcctx->call_cntr;
7168         max_calls = funcctx->max_calls;
7169         attinmeta = funcctx->attinmeta;
7170
7171         if (call_cntr < max_calls)      /* do when there is more left to send */
7172         {
7173                 char       *values[NUM_PG_SETTINGS_ATTS];
7174                 bool            noshow;
7175                 HeapTuple       tuple;
7176                 Datum           result;
7177
7178                 /*
7179                  * Get the next visible GUC variable name and value
7180                  */
7181                 do
7182                 {
7183                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
7184                         if (noshow)
7185                         {
7186                                 /* bump the counter and get the next config setting */
7187                                 call_cntr = ++funcctx->call_cntr;
7188
7189                                 /* make sure we haven't gone too far now */
7190                                 if (call_cntr >= max_calls)
7191                                         SRF_RETURN_DONE(funcctx);
7192                         }
7193                 } while (noshow);
7194
7195                 /* build a tuple */
7196                 tuple = BuildTupleFromCStrings(attinmeta, values);
7197
7198                 /* make the tuple into a datum */
7199                 result = HeapTupleGetDatum(tuple);
7200
7201                 SRF_RETURN_NEXT(funcctx, result);
7202         }
7203         else
7204         {
7205                 /* do when there is no more left */
7206                 SRF_RETURN_DONE(funcctx);
7207         }
7208 }
7209
7210 static char *
7211 _ShowOption(struct config_generic * record, bool use_units)
7212 {
7213         char            buffer[256];
7214         const char *val;
7215
7216         switch (record->vartype)
7217         {
7218                 case PGC_BOOL:
7219                         {
7220                                 struct config_bool *conf = (struct config_bool *) record;
7221
7222                                 if (conf->show_hook)
7223                                         val = (*conf->show_hook) ();
7224                                 else
7225                                         val = *conf->variable ? "on" : "off";
7226                         }
7227                         break;
7228
7229                 case PGC_INT:
7230                         {
7231                                 struct config_int *conf = (struct config_int *) record;
7232
7233                                 if (conf->show_hook)
7234                                         val = (*conf->show_hook) ();
7235                                 else
7236                                 {
7237                                         /*
7238                                          * Use int64 arithmetic to avoid overflows in units
7239                                          * conversion.
7240                                          */
7241                                         int64           result = *conf->variable;
7242                                         const char *unit;
7243
7244                                         if (use_units && result > 0 &&
7245                                                 (record->flags & GUC_UNIT_MEMORY))
7246                                         {
7247                                                 switch (record->flags & GUC_UNIT_MEMORY)
7248                                                 {
7249                                                         case GUC_UNIT_BLOCKS:
7250                                                                 result *= BLCKSZ / 1024;
7251                                                                 break;
7252                                                         case GUC_UNIT_XBLOCKS:
7253                                                                 result *= XLOG_BLCKSZ / 1024;
7254                                                                 break;
7255                                                 }
7256
7257                                                 if (result % KB_PER_GB == 0)
7258                                                 {
7259                                                         result /= KB_PER_GB;
7260                                                         unit = "GB";
7261                                                 }
7262                                                 else if (result % KB_PER_MB == 0)
7263                                                 {
7264                                                         result /= KB_PER_MB;
7265                                                         unit = "MB";
7266                                                 }
7267                                                 else
7268                                                 {
7269                                                         unit = "kB";
7270                                                 }
7271                                         }
7272                                         else if (use_units && result > 0 &&
7273                                                          (record->flags & GUC_UNIT_TIME))
7274                                         {
7275                                                 switch (record->flags & GUC_UNIT_TIME)
7276                                                 {
7277                                                         case GUC_UNIT_S:
7278                                                                 result *= MS_PER_S;
7279                                                                 break;
7280                                                         case GUC_UNIT_MIN:
7281                                                                 result *= MS_PER_MIN;
7282                                                                 break;
7283                                                 }
7284
7285                                                 if (result % MS_PER_D == 0)
7286                                                 {
7287                                                         result /= MS_PER_D;
7288                                                         unit = "d";
7289                                                 }
7290                                                 else if (result % MS_PER_H == 0)
7291                                                 {
7292                                                         result /= MS_PER_H;
7293                                                         unit = "h";
7294                                                 }
7295                                                 else if (result % MS_PER_MIN == 0)
7296                                                 {
7297                                                         result /= MS_PER_MIN;
7298                                                         unit = "min";
7299                                                 }
7300                                                 else if (result % MS_PER_S == 0)
7301                                                 {
7302                                                         result /= MS_PER_S;
7303                                                         unit = "s";
7304                                                 }
7305                                                 else
7306                                                 {
7307                                                         unit = "ms";
7308                                                 }
7309                                         }
7310                                         else
7311                                                 unit = "";
7312
7313                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
7314                                                          result, unit);
7315                                         val = buffer;
7316                                 }
7317                         }
7318                         break;
7319
7320                 case PGC_REAL:
7321                         {
7322                                 struct config_real *conf = (struct config_real *) record;
7323
7324                                 if (conf->show_hook)
7325                                         val = (*conf->show_hook) ();
7326                                 else
7327                                 {
7328                                         snprintf(buffer, sizeof(buffer), "%g",
7329                                                          *conf->variable);
7330                                         val = buffer;
7331                                 }
7332                         }
7333                         break;
7334
7335                 case PGC_STRING:
7336                         {
7337                                 struct config_string *conf = (struct config_string *) record;
7338
7339                                 if (conf->show_hook)
7340                                         val = (*conf->show_hook) ();
7341                                 else if (*conf->variable && **conf->variable)
7342                                         val = *conf->variable;
7343                                 else
7344                                         val = "";
7345                         }
7346                         break;
7347
7348                 case PGC_ENUM:
7349                         {
7350                                 struct config_enum *conf = (struct config_enum *) record;
7351
7352                                 if (conf->show_hook)
7353                                         val = (*conf->show_hook) ();
7354                                 else
7355                                         val = config_enum_lookup_by_value(conf, *conf->variable);
7356                         }
7357                         break;
7358
7359                 default:
7360                         /* just to keep compiler quiet */
7361                         val = "???";
7362                         break;
7363         }
7364
7365         return pstrdup(val);
7366 }
7367
7368
7369 #ifdef EXEC_BACKEND
7370
7371 /*
7372  *      These routines dump out all non-default GUC options into a binary
7373  *      file that is read by all exec'ed backends.  The format is:
7374  *
7375  *              variable name, string, null terminated
7376  *              variable value, string, null terminated
7377  *              variable sourcefile, string, null terminated (empty if none)
7378  *              variable sourceline, integer
7379  *              variable source, integer
7380  *              variable scontext, integer
7381  */
7382 static void
7383 write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
7384 {
7385         if (gconf->source == PGC_S_DEFAULT)
7386                 return;
7387
7388         fprintf(fp, "%s", gconf->name);
7389         fputc(0, fp);
7390
7391         switch (gconf->vartype)
7392         {
7393                 case PGC_BOOL:
7394                         {
7395                                 struct config_bool *conf = (struct config_bool *) gconf;
7396
7397                                 if (*conf->variable)
7398                                         fprintf(fp, "true");
7399                                 else
7400                                         fprintf(fp, "false");
7401                         }
7402                         break;
7403
7404                 case PGC_INT:
7405                         {
7406                                 struct config_int *conf = (struct config_int *) gconf;
7407
7408                                 fprintf(fp, "%d", *conf->variable);
7409                         }
7410                         break;
7411
7412                 case PGC_REAL:
7413                         {
7414                                 struct config_real *conf = (struct config_real *) gconf;
7415
7416                                 fprintf(fp, "%.17g", *conf->variable);
7417                         }
7418                         break;
7419
7420                 case PGC_STRING:
7421                         {
7422                                 struct config_string *conf = (struct config_string *) gconf;
7423
7424                                 fprintf(fp, "%s", *conf->variable);
7425                         }
7426                         break;
7427
7428                 case PGC_ENUM:
7429                         {
7430                                 struct config_enum *conf = (struct config_enum *) gconf;
7431
7432                                 fprintf(fp, "%s",
7433                                                 config_enum_lookup_by_value(conf, *conf->variable));
7434                         }
7435                         break;
7436         }
7437
7438         fputc(0, fp);
7439
7440         if (gconf->sourcefile)
7441                 fprintf(fp, "%s", gconf->sourcefile);
7442         fputc(0, fp);
7443
7444         fwrite(&gconf->sourceline, 1, sizeof(gconf->sourceline), fp);
7445         fwrite(&gconf->source, 1, sizeof(gconf->source), fp);
7446         fwrite(&gconf->scontext, 1, sizeof(gconf->scontext), fp);
7447 }
7448
7449 void
7450 write_nondefault_variables(GucContext context)
7451 {
7452         int                     elevel;
7453         FILE       *fp;
7454         int                     i;
7455
7456         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
7457
7458         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
7459
7460         /*
7461          * Open file
7462          */
7463         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
7464         if (!fp)
7465         {
7466                 ereport(elevel,
7467                                 (errcode_for_file_access(),
7468                                  errmsg("could not write to file \"%s\": %m",
7469                                                 CONFIG_EXEC_PARAMS_NEW)));
7470                 return;
7471         }
7472
7473         for (i = 0; i < num_guc_variables; i++)
7474         {
7475                 write_one_nondefault_variable(fp, guc_variables[i]);
7476         }
7477
7478         if (FreeFile(fp))
7479         {
7480                 ereport(elevel,
7481                                 (errcode_for_file_access(),
7482                                  errmsg("could not write to file \"%s\": %m",
7483                                                 CONFIG_EXEC_PARAMS_NEW)));
7484                 return;
7485         }
7486
7487         /*
7488          * Put new file in place.  This could delay on Win32, but we don't hold
7489          * any exclusive locks.
7490          */
7491         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
7492 }
7493
7494
7495 /*
7496  *      Read string, including null byte from file
7497  *
7498  *      Return NULL on EOF and nothing read
7499  */
7500 static char *
7501 read_string_with_null(FILE *fp)
7502 {
7503         int                     i = 0,
7504                                 ch,
7505                                 maxlen = 256;
7506         char       *str = NULL;
7507
7508         do
7509         {
7510                 if ((ch = fgetc(fp)) == EOF)
7511                 {
7512                         if (i == 0)
7513                                 return NULL;
7514                         else
7515                                 elog(FATAL, "invalid format of exec config params file");
7516                 }
7517                 if (i == 0)
7518                         str = guc_malloc(FATAL, maxlen);
7519                 else if (i == maxlen)
7520                         str = guc_realloc(FATAL, str, maxlen *= 2);
7521                 str[i++] = ch;
7522         } while (ch != 0);
7523
7524         return str;
7525 }
7526
7527
7528 /*
7529  *      This routine loads a previous postmaster dump of its non-default
7530  *      settings.
7531  */
7532 void
7533 read_nondefault_variables(void)
7534 {
7535         FILE       *fp;
7536         char       *varname,
7537                            *varvalue,
7538                            *varsourcefile;
7539         int                     varsourceline;
7540         GucSource       varsource;
7541         GucContext      varscontext;
7542
7543         /*
7544          * Open file
7545          */
7546         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
7547         if (!fp)
7548         {
7549                 /* File not found is fine */
7550                 if (errno != ENOENT)
7551                         ereport(FATAL,
7552                                         (errcode_for_file_access(),
7553                                          errmsg("could not read from file \"%s\": %m",
7554                                                         CONFIG_EXEC_PARAMS)));
7555                 return;
7556         }
7557
7558         for (;;)
7559         {
7560                 struct config_generic *record;
7561
7562                 if ((varname = read_string_with_null(fp)) == NULL)
7563                         break;
7564
7565                 if ((record = find_option(varname, true, FATAL)) == NULL)
7566                         elog(FATAL, "failed to locate variable \"%s\" in exec config params file", varname);
7567
7568                 if ((varvalue = read_string_with_null(fp)) == NULL)
7569                         elog(FATAL, "invalid format of exec config params file");
7570                 if ((varsourcefile = read_string_with_null(fp)) == NULL)
7571                         elog(FATAL, "invalid format of exec config params file");
7572                 if (fread(&varsourceline, 1, sizeof(varsourceline), fp) != sizeof(varsourceline))
7573                         elog(FATAL, "invalid format of exec config params file");
7574                 if (fread(&varsource, 1, sizeof(varsource), fp) != sizeof(varsource))
7575                         elog(FATAL, "invalid format of exec config params file");
7576                 if (fread(&varscontext, 1, sizeof(varscontext), fp) != sizeof(varscontext))
7577                         elog(FATAL, "invalid format of exec config params file");
7578
7579                 (void) set_config_option(varname, varvalue,
7580                                                                  varscontext, varsource,
7581                                                                  GUC_ACTION_SET, true, 0);
7582                 if (varsourcefile[0])
7583                         set_config_sourcefile(varname, varsourcefile, varsourceline);
7584
7585                 free(varname);
7586                 free(varvalue);
7587                 free(varsourcefile);
7588         }
7589
7590         FreeFile(fp);
7591 }
7592 #endif   /* EXEC_BACKEND */
7593
7594
7595 /*
7596  * A little "long argument" simulation, although not quite GNU
7597  * compliant. Takes a string of the form "some-option=some value" and
7598  * returns name = "some_option" and value = "some value" in malloc'ed
7599  * storage. Note that '-' is converted to '_' in the option name. If
7600  * there is no '=' in the input string then value will be NULL.
7601  */
7602 void
7603 ParseLongOption(const char *string, char **name, char **value)
7604 {
7605         size_t          equal_pos;
7606         char       *cp;
7607
7608         AssertArg(string);
7609         AssertArg(name);
7610         AssertArg(value);
7611
7612         equal_pos = strcspn(string, "=");
7613
7614         if (string[equal_pos] == '=')
7615         {
7616                 *name = guc_malloc(FATAL, equal_pos + 1);
7617                 strlcpy(*name, string, equal_pos + 1);
7618
7619                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
7620         }
7621         else
7622         {
7623                 /* no equal sign in string */
7624                 *name = guc_strdup(FATAL, string);
7625                 *value = NULL;
7626         }
7627
7628         for (cp = *name; *cp; cp++)
7629                 if (*cp == '-')
7630                         *cp = '_';
7631 }
7632
7633
7634 /*
7635  * Handle options fetched from pg_db_role_setting.setconfig,
7636  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
7637  *
7638  * The array parameter must be an array of TEXT (it must not be NULL).
7639  */
7640 void
7641 ProcessGUCArray(ArrayType *array,
7642                                 GucContext context, GucSource source, GucAction action)
7643 {
7644         int                     i;
7645
7646         Assert(array != NULL);
7647         Assert(ARR_ELEMTYPE(array) == TEXTOID);
7648         Assert(ARR_NDIM(array) == 1);
7649         Assert(ARR_LBOUND(array)[0] == 1);
7650
7651         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7652         {
7653                 Datum           d;
7654                 bool            isnull;
7655                 char       *s;
7656                 char       *name;
7657                 char       *value;
7658
7659                 d = array_ref(array, 1, &i,
7660                                           -1 /* varlenarray */ ,
7661                                           -1 /* TEXT's typlen */ ,
7662                                           false /* TEXT's typbyval */ ,
7663                                           'i' /* TEXT's typalign */ ,
7664                                           &isnull);
7665
7666                 if (isnull)
7667                         continue;
7668
7669                 s = TextDatumGetCString(d);
7670
7671                 ParseLongOption(s, &name, &value);
7672                 if (!value)
7673                 {
7674                         ereport(WARNING,
7675                                         (errcode(ERRCODE_SYNTAX_ERROR),
7676                                          errmsg("could not parse setting for parameter \"%s\"",
7677                                                         name)));
7678                         free(name);
7679                         continue;
7680                 }
7681
7682                 (void) set_config_option(name, value,
7683                                                                  context, source,
7684                                                                  action, true, 0);
7685
7686                 free(name);
7687                 if (value)
7688                         free(value);
7689                 pfree(s);
7690         }
7691 }
7692
7693
7694 /*
7695  * Add an entry to an option array.  The array parameter may be NULL
7696  * to indicate the current table entry is NULL.
7697  */
7698 ArrayType *
7699 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7700 {
7701         struct config_generic *record;
7702         Datum           datum;
7703         char       *newval;
7704         ArrayType  *a;
7705
7706         Assert(name);
7707         Assert(value);
7708
7709         /* test if the option is valid and we're allowed to set it */
7710         (void) validate_option_array_item(name, value, false);
7711
7712         /* normalize name (converts obsolete GUC names to modern spellings) */
7713         record = find_option(name, false, WARNING);
7714         if (record)
7715                 name = record->name;
7716
7717         /* build new item for array */
7718         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7719         sprintf(newval, "%s=%s", name, value);
7720         datum = CStringGetTextDatum(newval);
7721
7722         if (array)
7723         {
7724                 int                     index;
7725                 bool            isnull;
7726                 int                     i;
7727
7728                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7729                 Assert(ARR_NDIM(array) == 1);
7730                 Assert(ARR_LBOUND(array)[0] == 1);
7731
7732                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7733
7734                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7735                 {
7736                         Datum           d;
7737                         char       *current;
7738
7739                         d = array_ref(array, 1, &i,
7740                                                   -1 /* varlenarray */ ,
7741                                                   -1 /* TEXT's typlen */ ,
7742                                                   false /* TEXT's typbyval */ ,
7743                                                   'i' /* TEXT's typalign */ ,
7744                                                   &isnull);
7745                         if (isnull)
7746                                 continue;
7747                         current = TextDatumGetCString(d);
7748
7749                         /* check for match up through and including '=' */
7750                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7751                         {
7752                                 index = i;
7753                                 break;
7754                         }
7755                 }
7756
7757                 a = array_set(array, 1, &index,
7758                                           datum,
7759                                           false,
7760                                           -1 /* varlena array */ ,
7761                                           -1 /* TEXT's typlen */ ,
7762                                           false /* TEXT's typbyval */ ,
7763                                           'i' /* TEXT's typalign */ );
7764         }
7765         else
7766                 a = construct_array(&datum, 1,
7767                                                         TEXTOID,
7768                                                         -1, false, 'i');
7769
7770         return a;
7771 }
7772
7773
7774 /*
7775  * Delete an entry from an option array.  The array parameter may be NULL
7776  * to indicate the current table entry is NULL.  Also, if the return value
7777  * is NULL then a null should be stored.
7778  */
7779 ArrayType *
7780 GUCArrayDelete(ArrayType *array, const char *name)
7781 {
7782         struct config_generic *record;
7783         ArrayType  *newarray;
7784         int                     i;
7785         int                     index;
7786
7787         Assert(name);
7788
7789         /* test if the option is valid and we're allowed to set it */
7790         (void) validate_option_array_item(name, NULL, false);
7791
7792         /* normalize name (converts obsolete GUC names to modern spellings) */
7793         record = find_option(name, false, WARNING);
7794         if (record)
7795                 name = record->name;
7796
7797         /* if array is currently null, then surely nothing to delete */
7798         if (!array)
7799                 return NULL;
7800
7801         newarray = NULL;
7802         index = 1;
7803
7804         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7805         {
7806                 Datum           d;
7807                 char       *val;
7808                 bool            isnull;
7809
7810                 d = array_ref(array, 1, &i,
7811                                           -1 /* varlenarray */ ,
7812                                           -1 /* TEXT's typlen */ ,
7813                                           false /* TEXT's typbyval */ ,
7814                                           'i' /* TEXT's typalign */ ,
7815                                           &isnull);
7816                 if (isnull)
7817                         continue;
7818                 val = TextDatumGetCString(d);
7819
7820                 /* ignore entry if it's what we want to delete */
7821                 if (strncmp(val, name, strlen(name)) == 0
7822                         && val[strlen(name)] == '=')
7823                         continue;
7824
7825                 /* else add it to the output array */
7826                 if (newarray)
7827                         newarray = array_set(newarray, 1, &index,
7828                                                                  d,
7829                                                                  false,
7830                                                                  -1 /* varlenarray */ ,
7831                                                                  -1 /* TEXT's typlen */ ,
7832                                                                  false /* TEXT's typbyval */ ,
7833                                                                  'i' /* TEXT's typalign */ );
7834                 else
7835                         newarray = construct_array(&d, 1,
7836                                                                            TEXTOID,
7837                                                                            -1, false, 'i');
7838
7839                 index++;
7840         }
7841
7842         return newarray;
7843 }
7844
7845
7846 /*
7847  * Given a GUC array, delete all settings from it that our permission
7848  * level allows: if superuser, delete them all; if regular user, only
7849  * those that are PGC_USERSET
7850  */
7851 ArrayType *
7852 GUCArrayReset(ArrayType *array)
7853 {
7854         ArrayType  *newarray;
7855         int                     i;
7856         int                     index;
7857
7858         /* if array is currently null, nothing to do */
7859         if (!array)
7860                 return NULL;
7861
7862         /* if we're superuser, we can delete everything, so just do it */
7863         if (superuser())
7864                 return NULL;
7865
7866         newarray = NULL;
7867         index = 1;
7868
7869         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7870         {
7871                 Datum           d;
7872                 char       *val;
7873                 char       *eqsgn;
7874                 bool            isnull;
7875
7876                 d = array_ref(array, 1, &i,
7877                                           -1 /* varlenarray */ ,
7878                                           -1 /* TEXT's typlen */ ,
7879                                           false /* TEXT's typbyval */ ,
7880                                           'i' /* TEXT's typalign */ ,
7881                                           &isnull);
7882                 if (isnull)
7883                         continue;
7884                 val = TextDatumGetCString(d);
7885
7886                 eqsgn = strchr(val, '=');
7887                 *eqsgn = '\0';
7888
7889                 /* skip if we have permission to delete it */
7890                 if (validate_option_array_item(val, NULL, true))
7891                         continue;
7892
7893                 /* else add it to the output array */
7894                 if (newarray)
7895                         newarray = array_set(newarray, 1, &index,
7896                                                                  d,
7897                                                                  false,
7898                                                                  -1 /* varlenarray */ ,
7899                                                                  -1 /* TEXT's typlen */ ,
7900                                                                  false /* TEXT's typbyval */ ,
7901                                                                  'i' /* TEXT's typalign */ );
7902                 else
7903                         newarray = construct_array(&d, 1,
7904                                                                            TEXTOID,
7905                                                                            -1, false, 'i');
7906
7907                 index++;
7908                 pfree(val);
7909         }
7910
7911         return newarray;
7912 }
7913
7914 /*
7915  * Validate a proposed option setting for GUCArrayAdd/Delete/Reset.
7916  *
7917  * name is the option name.  value is the proposed value for the Add case,
7918  * or NULL for the Delete/Reset cases.  If skipIfNoPermissions is true, it's
7919  * not an error to have no permissions to set the option.
7920  *
7921  * Returns TRUE if OK, FALSE if skipIfNoPermissions is true and user does not
7922  * have permission to change this option (all other error cases result in an
7923  * error being thrown).
7924  */
7925 static bool
7926 validate_option_array_item(const char *name, const char *value,
7927                                                    bool skipIfNoPermissions)
7928
7929 {
7930         struct config_generic *gconf;
7931
7932         /*
7933          * There are three cases to consider:
7934          *
7935          * name is a known GUC variable.  Check the value normally, check
7936          * permissions normally (ie, allow if variable is USERSET, or if it's
7937          * SUSET and user is superuser).
7938          *
7939          * name is not known, but exists or can be created as a placeholder (i.e.,
7940          * it has a prefixed name).  We allow this case if you're a superuser,
7941          * otherwise not.  Superusers are assumed to know what they're doing.
7942          * We can't allow it for other users, because when the placeholder is
7943          * resolved it might turn out to be a SUSET variable;
7944          * define_custom_variable assumes we checked that.
7945          *
7946          * name is not known and can't be created as a placeholder.  Throw error,
7947          * unless skipIfNoPermissions is true, in which case return FALSE.
7948          */
7949         gconf = find_option(name, true, WARNING);
7950         if (!gconf)
7951         {
7952                 /* not known, failed to make a placeholder */
7953                 if (skipIfNoPermissions)
7954                         return false;
7955                 ereport(ERROR,
7956                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
7957                                  errmsg("unrecognized configuration parameter \"%s\"",
7958                                                 name)));
7959         }
7960
7961         if (gconf->flags & GUC_CUSTOM_PLACEHOLDER)
7962         {
7963                 /*
7964                  * We cannot do any meaningful check on the value, so only permissions
7965                  * are useful to check.
7966                  */
7967                 if (superuser())
7968                         return true;
7969                 if (skipIfNoPermissions)
7970                         return false;
7971                 ereport(ERROR,
7972                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
7973                                  errmsg("permission denied to set parameter \"%s\"", name)));
7974         }
7975
7976         /* manual permissions check so we can avoid an error being thrown */
7977         if (gconf->context == PGC_USERSET)
7978                  /* ok */ ;
7979         else if (gconf->context == PGC_SUSET && superuser())
7980                  /* ok */ ;
7981         else if (skipIfNoPermissions)
7982                 return false;
7983         /* if a permissions error should be thrown, let set_config_option do it */
7984
7985         /* test for permissions and valid option value */
7986         (void) set_config_option(name, value,
7987                                                          superuser() ? PGC_SUSET : PGC_USERSET,
7988                                                          PGC_S_TEST, GUC_ACTION_SET, false, 0);
7989
7990         return true;
7991 }
7992
7993
7994 /*
7995  * Called by check_hooks that want to override the normal
7996  * ERRCODE_INVALID_PARAMETER_VALUE SQLSTATE for check hook failures.
7997  *
7998  * Note that GUC_check_errmsg() etc are just macros that result in a direct
7999  * assignment to the associated variables.      That is ugly, but forced by the
8000  * limitations of C's macro mechanisms.
8001  */
8002 void
8003 GUC_check_errcode(int sqlerrcode)
8004 {
8005         GUC_check_errcode_value = sqlerrcode;
8006 }
8007
8008
8009 /*
8010  * Convenience functions to manage calling a variable's check_hook.
8011  * These mostly take care of the protocol for letting check hooks supply
8012  * portions of the error report on failure.
8013  */
8014
8015 static bool
8016 call_bool_check_hook(struct config_bool * conf, bool *newval, void **extra,
8017                                          GucSource source, int elevel)
8018 {
8019         /* Quick success if no hook */
8020         if (!conf->check_hook)
8021                 return true;
8022
8023         /* Reset variables that might be set by hook */
8024         GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
8025         GUC_check_errmsg_string = NULL;
8026         GUC_check_errdetail_string = NULL;
8027         GUC_check_errhint_string = NULL;
8028
8029         if (!(*conf->check_hook) (newval, extra, source))
8030         {
8031                 ereport(elevel,
8032                                 (errcode(GUC_check_errcode_value),
8033                                  GUC_check_errmsg_string ?
8034                                  errmsg_internal("%s", GUC_check_errmsg_string) :
8035                                  errmsg("invalid value for parameter \"%s\": %d",
8036                                                 conf->gen.name, (int) *newval),
8037                                  GUC_check_errdetail_string ?
8038                                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
8039                                  GUC_check_errhint_string ?
8040                                  errhint("%s", GUC_check_errhint_string) : 0));
8041                 /* Flush any strings created in ErrorContext */
8042                 FlushErrorState();
8043                 return false;
8044         }
8045
8046         return true;
8047 }
8048
8049 static bool
8050 call_int_check_hook(struct config_int * conf, int *newval, void **extra,
8051                                         GucSource source, int elevel)
8052 {
8053         /* Quick success if no hook */
8054         if (!conf->check_hook)
8055                 return true;
8056
8057         /* Reset variables that might be set by hook */
8058         GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
8059         GUC_check_errmsg_string = NULL;
8060         GUC_check_errdetail_string = NULL;
8061         GUC_check_errhint_string = NULL;
8062
8063         if (!(*conf->check_hook) (newval, extra, source))
8064         {
8065                 ereport(elevel,
8066                                 (errcode(GUC_check_errcode_value),
8067                                  GUC_check_errmsg_string ?
8068                                  errmsg_internal("%s", GUC_check_errmsg_string) :
8069                                  errmsg("invalid value for parameter \"%s\": %d",
8070                                                 conf->gen.name, *newval),
8071                                  GUC_check_errdetail_string ?
8072                                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
8073                                  GUC_check_errhint_string ?
8074                                  errhint("%s", GUC_check_errhint_string) : 0));
8075                 /* Flush any strings created in ErrorContext */
8076                 FlushErrorState();
8077                 return false;
8078         }
8079
8080         return true;
8081 }
8082
8083 static bool
8084 call_real_check_hook(struct config_real * conf, double *newval, void **extra,
8085                                          GucSource source, int elevel)
8086 {
8087         /* Quick success if no hook */
8088         if (!conf->check_hook)
8089                 return true;
8090
8091         /* Reset variables that might be set by hook */
8092         GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
8093         GUC_check_errmsg_string = NULL;
8094         GUC_check_errdetail_string = NULL;
8095         GUC_check_errhint_string = NULL;
8096
8097         if (!(*conf->check_hook) (newval, extra, source))
8098         {
8099                 ereport(elevel,
8100                                 (errcode(GUC_check_errcode_value),
8101                                  GUC_check_errmsg_string ?
8102                                  errmsg_internal("%s", GUC_check_errmsg_string) :
8103                                  errmsg("invalid value for parameter \"%s\": %g",
8104                                                 conf->gen.name, *newval),
8105                                  GUC_check_errdetail_string ?
8106                                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
8107                                  GUC_check_errhint_string ?
8108                                  errhint("%s", GUC_check_errhint_string) : 0));
8109                 /* Flush any strings created in ErrorContext */
8110                 FlushErrorState();
8111                 return false;
8112         }
8113
8114         return true;
8115 }
8116
8117 static bool
8118 call_string_check_hook(struct config_string * conf, char **newval, void **extra,
8119                                            GucSource source, int elevel)
8120 {
8121         /* Quick success if no hook */
8122         if (!conf->check_hook)
8123                 return true;
8124
8125         /* Reset variables that might be set by hook */
8126         GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
8127         GUC_check_errmsg_string = NULL;
8128         GUC_check_errdetail_string = NULL;
8129         GUC_check_errhint_string = NULL;
8130
8131         if (!(*conf->check_hook) (newval, extra, source))
8132         {
8133                 ereport(elevel,
8134                                 (errcode(GUC_check_errcode_value),
8135                                  GUC_check_errmsg_string ?
8136                                  errmsg_internal("%s", GUC_check_errmsg_string) :
8137                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
8138                                                 conf->gen.name, *newval ? *newval : ""),
8139                                  GUC_check_errdetail_string ?
8140                                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
8141                                  GUC_check_errhint_string ?
8142                                  errhint("%s", GUC_check_errhint_string) : 0));
8143                 /* Flush any strings created in ErrorContext */
8144                 FlushErrorState();
8145                 return false;
8146         }
8147
8148         return true;
8149 }
8150
8151 static bool
8152 call_enum_check_hook(struct config_enum * conf, int *newval, void **extra,
8153                                          GucSource source, int elevel)
8154 {
8155         /* Quick success if no hook */
8156         if (!conf->check_hook)
8157                 return true;
8158
8159         /* Reset variables that might be set by hook */
8160         GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
8161         GUC_check_errmsg_string = NULL;
8162         GUC_check_errdetail_string = NULL;
8163         GUC_check_errhint_string = NULL;
8164
8165         if (!(*conf->check_hook) (newval, extra, source))
8166         {
8167                 ereport(elevel,
8168                                 (errcode(GUC_check_errcode_value),
8169                                  GUC_check_errmsg_string ?
8170                                  errmsg_internal("%s", GUC_check_errmsg_string) :
8171                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
8172                                                 conf->gen.name,
8173                                                 config_enum_lookup_by_value(conf, *newval)),
8174                                  GUC_check_errdetail_string ?
8175                                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
8176                                  GUC_check_errhint_string ?
8177                                  errhint("%s", GUC_check_errhint_string) : 0));
8178                 /* Flush any strings created in ErrorContext */
8179                 FlushErrorState();
8180                 return false;
8181         }
8182
8183         return true;
8184 }
8185
8186
8187 /*
8188  * check_hook, assign_hook and show_hook subroutines
8189  */
8190
8191 static bool
8192 check_log_destination(char **newval, void **extra, GucSource source)
8193 {
8194         char       *rawstring;
8195         List       *elemlist;
8196         ListCell   *l;
8197         int                     newlogdest = 0;
8198         int                *myextra;
8199
8200         /* Need a modifiable copy of string */
8201         rawstring = pstrdup(*newval);
8202
8203         /* Parse string into list of identifiers */
8204         if (!SplitIdentifierString(rawstring, ',', &elemlist))
8205         {
8206                 /* syntax error in list */
8207                 GUC_check_errdetail("List syntax is invalid.");
8208                 pfree(rawstring);
8209                 list_free(elemlist);
8210                 return false;
8211         }
8212
8213         foreach(l, elemlist)
8214         {
8215                 char       *tok = (char *) lfirst(l);
8216
8217                 if (pg_strcasecmp(tok, "stderr") == 0)
8218                         newlogdest |= LOG_DESTINATION_STDERR;
8219                 else if (pg_strcasecmp(tok, "csvlog") == 0)
8220                         newlogdest |= LOG_DESTINATION_CSVLOG;
8221 #ifdef HAVE_SYSLOG
8222                 else if (pg_strcasecmp(tok, "syslog") == 0)
8223                         newlogdest |= LOG_DESTINATION_SYSLOG;
8224 #endif
8225 #ifdef WIN32
8226                 else if (pg_strcasecmp(tok, "eventlog") == 0)
8227                         newlogdest |= LOG_DESTINATION_EVENTLOG;
8228 #endif
8229                 else
8230                 {
8231                         GUC_check_errdetail("Unrecognized key word: \"%s\".", tok);
8232                         pfree(rawstring);
8233                         list_free(elemlist);
8234                         return false;
8235                 }
8236         }
8237
8238         pfree(rawstring);
8239         list_free(elemlist);
8240
8241         myextra = (int *) guc_malloc(ERROR, sizeof(int));
8242         *myextra = newlogdest;
8243         *extra = (void *) myextra;
8244
8245         return true;
8246 }
8247
8248 static void
8249 assign_log_destination(const char *newval, void *extra)
8250 {
8251         Log_destination = *((int *) extra);
8252 }
8253
8254 static void
8255 assign_syslog_facility(int newval, void *extra)
8256 {
8257 #ifdef HAVE_SYSLOG
8258         set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
8259                                                   newval);
8260 #endif
8261         /* Without syslog support, just ignore it */
8262 }
8263
8264 static void
8265 assign_syslog_ident(const char *newval, void *extra)
8266 {
8267 #ifdef HAVE_SYSLOG
8268         set_syslog_parameters(newval, syslog_facility);
8269 #endif
8270         /* Without syslog support, it will always be set to "none", so ignore */
8271 }
8272
8273
8274 static void
8275 assign_session_replication_role(int newval, void *extra)
8276 {
8277         /*
8278          * Must flush the plan cache when changing replication role; but don't
8279          * flush unnecessarily.
8280          */
8281         if (SessionReplicationRole != newval)
8282                 ResetPlanCache();
8283 }
8284
8285 static bool
8286 check_temp_buffers(int *newval, void **extra, GucSource source)
8287 {
8288         /*
8289          * Once local buffers have been initialized, it's too late to change this.
8290          */
8291         if (NLocBuffer && NLocBuffer != *newval)
8292         {
8293                 GUC_check_errdetail("\"temp_buffers\" cannot be changed after any temporary tables have been accessed in the session.");
8294                 return false;
8295         }
8296         return true;
8297 }
8298
8299 static bool
8300 check_phony_autocommit(bool *newval, void **extra, GucSource source)
8301 {
8302         if (!*newval)
8303         {
8304                 GUC_check_errcode(ERRCODE_FEATURE_NOT_SUPPORTED);
8305                 GUC_check_errmsg("SET AUTOCOMMIT TO OFF is no longer supported");
8306                 return false;
8307         }
8308         return true;
8309 }
8310
8311 static bool
8312 check_debug_assertions(bool *newval, void **extra, GucSource source)
8313 {
8314 #ifndef USE_ASSERT_CHECKING
8315         if (*newval)
8316         {
8317                 GUC_check_errmsg("assertion checking is not supported by this build");
8318                 return false;
8319         }
8320 #endif
8321         return true;
8322 }
8323
8324 static bool
8325 check_bonjour(bool *newval, void **extra, GucSource source)
8326 {
8327 #ifndef USE_BONJOUR
8328         if (*newval)
8329         {
8330                 GUC_check_errmsg("Bonjour is not supported by this build");
8331                 return false;
8332         }
8333 #endif
8334         return true;
8335 }
8336
8337 static bool
8338 check_ssl(bool *newval, void **extra, GucSource source)
8339 {
8340 #ifndef USE_SSL
8341         if (*newval)
8342         {
8343                 GUC_check_errmsg("SSL is not supported by this build");
8344                 return false;
8345         }
8346 #endif
8347         return true;
8348 }
8349
8350 static bool
8351 check_stage_log_stats(bool *newval, void **extra, GucSource source)
8352 {
8353         if (*newval && log_statement_stats)
8354         {
8355                 GUC_check_errdetail("Cannot enable parameter when \"log_statement_stats\" is true.");
8356                 return false;
8357         }
8358         return true;
8359 }
8360
8361 static bool
8362 check_log_stats(bool *newval, void **extra, GucSource source)
8363 {
8364         if (*newval &&
8365                 (log_parser_stats || log_planner_stats || log_executor_stats))
8366         {
8367                 GUC_check_errdetail("Cannot enable \"log_statement_stats\" when "
8368                                                         "\"log_parser_stats\", \"log_planner_stats\", "
8369                                                         "or \"log_executor_stats\" is true.");
8370                 return false;
8371         }
8372         return true;
8373 }
8374
8375 static bool
8376 check_canonical_path(char **newval, void **extra, GucSource source)
8377 {
8378         /*
8379          * Since canonicalize_path never enlarges the string, we can just modify
8380          * newval in-place.  But watch out for NULL, which is the default value
8381          * for external_pid_file.
8382          */
8383         if (*newval)
8384                 canonicalize_path(*newval);
8385         return true;
8386 }
8387
8388 static bool
8389 check_timezone_abbreviations(char **newval, void **extra, GucSource source)
8390 {
8391         /*
8392          * The boot_val given above for timezone_abbreviations is NULL. When we
8393          * see this we just do nothing.  If this value isn't overridden from the
8394          * config file then pg_timezone_abbrev_initialize() will eventually
8395          * replace it with "Default".  This hack has two purposes: to avoid
8396          * wasting cycles loading values that might soon be overridden from the
8397          * config file, and to avoid trying to read the timezone abbrev files
8398          * during InitializeGUCOptions().  The latter doesn't work in an
8399          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
8400          * we can't locate PGSHAREDIR.
8401          */
8402         if (*newval == NULL)
8403         {
8404                 Assert(source == PGC_S_DEFAULT);
8405                 return true;
8406         }
8407
8408         /* OK, load the file and produce a malloc'd TimeZoneAbbrevTable */
8409         *extra = load_tzoffsets(*newval);
8410
8411         /* tzparser.c returns NULL on failure, reporting via GUC_check_errmsg */
8412         if (!*extra)
8413                 return false;
8414
8415         return true;
8416 }
8417
8418 static void
8419 assign_timezone_abbreviations(const char *newval, void *extra)
8420 {
8421         /* Do nothing for the boot_val default of NULL */
8422         if (!extra)
8423                 return;
8424
8425         InstallTimeZoneAbbrevs((TimeZoneAbbrevTable *) extra);
8426 }
8427
8428 /*
8429  * pg_timezone_abbrev_initialize --- set default value if not done already
8430  *
8431  * This is called after initial loading of postgresql.conf.  If no
8432  * timezone_abbreviations setting was found therein, select default.
8433  * If a non-default value is already installed, nothing will happen.
8434  *
8435  * This can also be called from ProcessConfigFile to establish the default
8436  * value after a postgresql.conf entry for it is removed.
8437  */
8438 static void
8439 pg_timezone_abbrev_initialize(void)
8440 {
8441         SetConfigOption("timezone_abbreviations", "Default",
8442                                         PGC_POSTMASTER, PGC_S_DYNAMIC_DEFAULT);
8443 }
8444
8445 static const char *
8446 show_archive_command(void)
8447 {
8448         if (XLogArchivingActive())
8449                 return XLogArchiveCommand;
8450         else
8451                 return "(disabled)";
8452 }
8453
8454 static void
8455 assign_tcp_keepalives_idle(int newval, void *extra)
8456 {
8457         /*
8458          * The kernel API provides no way to test a value without setting it; and
8459          * once we set it we might fail to unset it.  So there seems little point
8460          * in fully implementing the check-then-assign GUC API for these
8461          * variables.  Instead we just do the assignment on demand.  pqcomm.c
8462          * reports any problems via elog(LOG).
8463          *
8464          * This approach means that the GUC value might have little to do with the
8465          * actual kernel value, so we use a show_hook that retrieves the kernel
8466          * value rather than trusting GUC's copy.
8467          */
8468         (void) pq_setkeepalivesidle(newval, MyProcPort);
8469 }
8470
8471 static const char *
8472 show_tcp_keepalives_idle(void)
8473 {
8474         /* See comments in assign_tcp_keepalives_idle */
8475         static char nbuf[16];
8476
8477         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
8478         return nbuf;
8479 }
8480
8481 static void
8482 assign_tcp_keepalives_interval(int newval, void *extra)
8483 {
8484         /* See comments in assign_tcp_keepalives_idle */
8485         (void) pq_setkeepalivesinterval(newval, MyProcPort);
8486 }
8487
8488 static const char *
8489 show_tcp_keepalives_interval(void)
8490 {
8491         /* See comments in assign_tcp_keepalives_idle */
8492         static char nbuf[16];
8493
8494         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
8495         return nbuf;
8496 }
8497
8498 static void
8499 assign_tcp_keepalives_count(int newval, void *extra)
8500 {
8501         /* See comments in assign_tcp_keepalives_idle */
8502         (void) pq_setkeepalivescount(newval, MyProcPort);
8503 }
8504
8505 static const char *
8506 show_tcp_keepalives_count(void)
8507 {
8508         /* See comments in assign_tcp_keepalives_idle */
8509         static char nbuf[16];
8510
8511         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
8512         return nbuf;
8513 }
8514
8515 static bool
8516 check_maxconnections(int *newval, void **extra, GucSource source)
8517 {
8518         if (*newval + autovacuum_max_workers + 1 > MAX_BACKENDS)
8519                 return false;
8520         return true;
8521 }
8522
8523 static void
8524 assign_maxconnections(int newval, void *extra)
8525 {
8526         MaxBackends = newval + autovacuum_max_workers + 1;
8527 }
8528
8529 static bool
8530 check_autovacuum_max_workers(int *newval, void **extra, GucSource source)
8531 {
8532         if (MaxConnections + *newval + 1 > MAX_BACKENDS)
8533                 return false;
8534         return true;
8535 }
8536
8537 static void
8538 assign_autovacuum_max_workers(int newval, void *extra)
8539 {
8540         MaxBackends = MaxConnections + newval + 1;
8541 }
8542
8543 static bool
8544 check_effective_io_concurrency(int *newval, void **extra, GucSource source)
8545 {
8546 #ifdef USE_PREFETCH
8547         double          new_prefetch_pages = 0.0;
8548         int                     i;
8549
8550         /*----------
8551          * The user-visible GUC parameter is the number of drives (spindles),
8552          * which we need to translate to a number-of-pages-to-prefetch target.
8553          * The target value is stashed in *extra and then assigned to the actual
8554          * variable by assign_effective_io_concurrency.
8555          *
8556          * The expected number of prefetch pages needed to keep N drives busy is:
8557          *
8558          * drives |   I/O requests
8559          * -------+----------------
8560          *              1 |   1
8561          *              2 |   2/1 + 2/2 = 3
8562          *              3 |   3/1 + 3/2 + 3/3 = 5 1/2
8563          *              4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
8564          *              n |   n * H(n)
8565          *
8566          * This is called the "coupon collector problem" and H(n) is called the
8567          * harmonic series.  This could be approximated by n * ln(n), but for
8568          * reasonable numbers of drives we might as well just compute the series.
8569          *
8570          * Alternatively we could set the target to the number of pages necessary
8571          * so that the expected number of active spindles is some arbitrary
8572          * percentage of the total.  This sounds the same but is actually slightly
8573          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
8574          * that desired fraction.
8575          *
8576          * Experimental results show that both of these formulas aren't aggressive
8577          * enough, but we don't really have any better proposals.
8578          *
8579          * Note that if *newval = 0 (disabled), we must set target = 0.
8580          *----------
8581          */
8582
8583         for (i = 1; i <= *newval; i++)
8584                 new_prefetch_pages += (double) *newval / (double) i;
8585
8586         /* This range check shouldn't fail, but let's be paranoid */
8587         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
8588         {
8589                 int                *myextra = (int *) guc_malloc(ERROR, sizeof(int));
8590
8591                 *myextra = (int) rint(new_prefetch_pages);
8592                 *extra = (void *) myextra;
8593
8594                 return true;
8595         }
8596         else
8597                 return false;
8598 #else
8599         return true;
8600 #endif   /* USE_PREFETCH */
8601 }
8602
8603 static void
8604 assign_effective_io_concurrency(int newval, void *extra)
8605 {
8606 #ifdef USE_PREFETCH
8607         target_prefetch_pages = *((int *) extra);
8608 #endif   /* USE_PREFETCH */
8609 }
8610
8611 static void
8612 assign_pgstat_temp_directory(const char *newval, void *extra)
8613 {
8614         /* check_canonical_path already canonicalized newval for us */
8615         char       *tname;
8616         char       *fname;
8617
8618         tname = guc_malloc(ERROR, strlen(newval) + 12);         /* /pgstat.tmp */
8619         sprintf(tname, "%s/pgstat.tmp", newval);
8620         fname = guc_malloc(ERROR, strlen(newval) + 13);         /* /pgstat.stat */
8621         sprintf(fname, "%s/pgstat.stat", newval);
8622
8623         if (pgstat_stat_tmpname)
8624                 free(pgstat_stat_tmpname);
8625         pgstat_stat_tmpname = tname;
8626         if (pgstat_stat_filename)
8627                 free(pgstat_stat_filename);
8628         pgstat_stat_filename = fname;
8629 }
8630
8631 static bool
8632 check_application_name(char **newval, void **extra, GucSource source)
8633 {
8634         /* Only allow clean ASCII chars in the application name */
8635         char       *p;
8636
8637         for (p = *newval; *p; p++)
8638         {
8639                 if (*p < 32 || *p > 126)
8640                         *p = '?';
8641         }
8642
8643         return true;
8644 }
8645
8646 static void
8647 assign_application_name(const char *newval, void *extra)
8648 {
8649         /* Update the pg_stat_activity view */
8650         pgstat_report_appname(newval);
8651 }
8652
8653 static const char *
8654 show_unix_socket_permissions(void)
8655 {
8656         static char buf[8];
8657
8658         snprintf(buf, sizeof(buf), "%04o", Unix_socket_permissions);
8659         return buf;
8660 }
8661
8662 static const char *
8663 show_log_file_mode(void)
8664 {
8665         static char buf[8];
8666
8667         snprintf(buf, sizeof(buf), "%04o", Log_file_mode);
8668         return buf;
8669 }
8670
8671 #include "guc-file.c"