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) 2000-2009, PostgreSQL Global Development Group
  10  * Written by Peter Eisentraut <peter_e@gmx.net>.
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.516 2009/09/08 17:08:36 tgl Exp $
  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/pqformat.h"
  42 #include "miscadmin.h"
  43 #include "optimizer/cost.h"
  44 #include "optimizer/geqo.h"
  45 #include "optimizer/paths.h"
  46 #include "optimizer/planmain.h"
  47 #include "parser/parse_expr.h"
  48 #include "parser/parse_relation.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 "regex/regex.h"
  59 #include "storage/bufmgr.h"
  60 #include "storage/fd.h"
  61 #include "tcop/tcopprot.h"
  62 #include "tsearch/ts_cache.h"
  63 #include "utils/builtins.h"
  64 #include "utils/bytea.h"
  65 #include "utils/guc_tables.h"
  66 #include "utils/memutils.h"
  67 #include "utils/pg_locale.h"
  68 #include "utils/plancache.h"
  69 #include "utils/portal.h"
  70 #include "utils/ps_status.h"
  71 #include "utils/tzparser.h"
  72 #include "utils/xml.h"
  73
  74 #ifndef PG_KRB_SRVTAB
  75 #define PG_KRB_SRVTAB ""
  76 #endif
  77 #ifndef PG_KRB_SRVNAM
  78 #define PG_KRB_SRVNAM ""
  79 #endif
  80
  81 #define CONFIG_FILENAME "postgresql.conf"
  82 #define HBA_FILENAME    "pg_hba.conf"
  83 #define IDENT_FILENAME  "pg_ident.conf"
  84
  85 #ifdef EXEC_BACKEND
  86 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  87 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  88 #endif
  89
  90 /* upper limit for GUC variables measured in kilobytes of memory */
  91 #if SIZEOF_SIZE_T > 4
  92 #define MAX_KILOBYTES   INT_MAX
  93 #else
  94 #define MAX_KILOBYTES   (INT_MAX / 1024)
  95 #endif
  96
  97 #define KB_PER_MB (1024)
  98 #define KB_PER_GB (1024*1024)
  99
 100 #define MS_PER_S 1000
 101 #define S_PER_MIN 60
 102 #define MS_PER_MIN (1000 * 60)
 103 #define MIN_PER_H 60
 104 #define S_PER_H (60 * 60)
 105 #define MS_PER_H (1000 * 60 * 60)
 106 #define MIN_PER_D (60 * 24)
 107 #define S_PER_D (60 * 60 * 24)
 108 #define MS_PER_D (1000 * 60 * 60 * 24)
 109
 110 /* XXX these should appear in other modules' header files */
 111 extern bool Log_disconnections;
 112 extern int      CommitDelay;
 113 extern int      CommitSiblings;
 114 extern char *default_tablespace;
 115 extern char *temp_tablespaces;
 116 extern bool synchronize_seqscans;
 117 extern bool fullPageWrites;
 118
 119 #ifdef TRACE_SORT
 120 extern bool trace_sort;
 121 #endif
 122 #ifdef TRACE_SYNCSCAN
 123 extern bool trace_syncscan;
 124 #endif
 125 #ifdef DEBUG_BOUNDED_SORT
 126 extern bool optimize_bounded_sort;
 127 #endif
 128
 129 #ifdef USE_SSL
 130 extern char *SSLCipherSuites;
 131 #endif
 132
 133 static void set_config_sourcefile(const char *name, char *sourcefile,
 134                                           int sourceline);
 135
 136 static const char *assign_log_destination(const char *value,
 137                                            bool doit, GucSource source);
 138
 139 #ifdef HAVE_SYSLOG
 140 static int      syslog_facility = LOG_LOCAL0;
 141
 142 static bool assign_syslog_facility(int newval,
 143                                            bool doit, GucSource source);
 144 static const char *assign_syslog_ident(const char *ident,
 145                                         bool doit, GucSource source);
 146 #endif
 147
 148 static bool assign_session_replication_role(int newval, bool doit,
 149                                                                 GucSource source);
 150 static const char *show_num_temp_buffers(void);
 151 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 152 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 153                                                            GucSource source);
 154 static bool assign_debug_assertions(bool newval, bool doit, GucSource source);
 155 static bool assign_bonjour(bool newval, bool doit, GucSource source);
 156 static bool assign_ssl(bool newval, bool doit, GucSource source);
 157 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 158 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 159 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 160 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 161 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 162 static const char *show_archive_command(void);
 163 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 164 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 165 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 166 static const char *show_tcp_keepalives_idle(void);
 167 static const char *show_tcp_keepalives_interval(void);
 168 static const char *show_tcp_keepalives_count(void);
 169 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 170 static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource source);
 171 static bool assign_effective_io_concurrency(int newval, bool doit, GucSource source);
 172 static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
 173
 174 static char *config_enum_get_options(struct config_enum * record,
 175                                                 const char *prefix, const char *suffix,
 176                                                 const char *separator);
 177
 178
 179 /*
 180  * Options for enum values defined in this module.
 181  *
 182  * NOTE! Option values may not contain double quotes!
 183  */
 184
 185 static const struct config_enum_entry bytea_output_options[] = {
 186         {"escape", BYTEA_OUTPUT_ESCAPE, false},
 187         {"hex", BYTEA_OUTPUT_HEX, false},
 188         {NULL, 0, false}
 189 };
 190
 191 /*
 192  * We have different sets for client and server message level options because
 193  * they sort slightly different (see "log" level)
 194  */
 195 static const struct config_enum_entry client_message_level_options[] = {
 196         {"debug", DEBUG2, true},
 197         {"debug5", DEBUG5, false},
 198         {"debug4", DEBUG4, false},
 199         {"debug3", DEBUG3, false},
 200         {"debug2", DEBUG2, false},
 201         {"debug1", DEBUG1, false},
 202         {"log", LOG, false},
 203         {"info", INFO, true},
 204         {"notice", NOTICE, false},
 205         {"warning", WARNING, false},
 206         {"error", ERROR, false},
 207         {"fatal", FATAL, true},
 208         {"panic", PANIC, true},
 209         {NULL, 0, false}
 210 };
 211
 212 static const struct config_enum_entry server_message_level_options[] = {
 213         {"debug", DEBUG2, true},
 214         {"debug5", DEBUG5, false},
 215         {"debug4", DEBUG4, false},
 216         {"debug3", DEBUG3, false},
 217         {"debug2", DEBUG2, false},
 218         {"debug1", DEBUG1, false},
 219         {"info", INFO, false},
 220         {"notice", NOTICE, false},
 221         {"warning", WARNING, false},
 222         {"error", ERROR, false},
 223         {"log", LOG, false},
 224         {"fatal", FATAL, false},
 225         {"panic", PANIC, false},
 226         {NULL, 0, false}
 227 };
 228
 229 static const struct config_enum_entry intervalstyle_options[] = {
 230         {"postgres", INTSTYLE_POSTGRES, false},
 231         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 232         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 233         {"iso_8601", INTSTYLE_ISO_8601, false},
 234         {NULL, 0, false}
 235 };
 236
 237 static const struct config_enum_entry log_error_verbosity_options[] = {
 238         {"terse", PGERROR_TERSE, false},
 239         {"default", PGERROR_DEFAULT, false},
 240         {"verbose", PGERROR_VERBOSE, false},
 241         {NULL, 0, false}
 242 };
 243
 244 static const struct config_enum_entry log_statement_options[] = {
 245         {"none", LOGSTMT_NONE, false},
 246         {"ddl", LOGSTMT_DDL, false},
 247         {"mod", LOGSTMT_MOD, false},
 248         {"all", LOGSTMT_ALL, false},
 249         {NULL, 0, false}
 250 };
 251
 252 static const struct config_enum_entry regex_flavor_options[] = {
 253         {"advanced", REG_ADVANCED, false},
 254         {"extended", REG_EXTENDED, false},
 255         {"basic", REG_BASIC, false},
 256         {NULL, 0, false}
 257 };
 258
 259 static const struct config_enum_entry isolation_level_options[] = {
 260         {"serializable", XACT_SERIALIZABLE, false},
 261         {"repeatable read", XACT_REPEATABLE_READ, false},
 262         {"read committed", XACT_READ_COMMITTED, false},
 263         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 264         {NULL, 0}
 265 };
 266
 267 static const struct config_enum_entry session_replication_role_options[] = {
 268         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 269         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 270         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 271         {NULL, 0, false}
 272 };
 273
 274 #ifdef HAVE_SYSLOG
 275 static const struct config_enum_entry syslog_facility_options[] = {
 276         {"local0", LOG_LOCAL0, false},
 277         {"local1", LOG_LOCAL1, false},
 278         {"local2", LOG_LOCAL2, false},
 279         {"local3", LOG_LOCAL3, false},
 280         {"local4", LOG_LOCAL4, false},
 281         {"local5", LOG_LOCAL5, false},
 282         {"local6", LOG_LOCAL6, false},
 283         {"local7", LOG_LOCAL7, false},
 284         {NULL, 0}
 285 };
 286 #endif
 287
 288 static const struct config_enum_entry track_function_options[] = {
 289         {"none", TRACK_FUNC_OFF, false},
 290         {"pl", TRACK_FUNC_PL, false},
 291         {"all", TRACK_FUNC_ALL, false},
 292         {NULL, 0, false}
 293 };
 294
 295 static const struct config_enum_entry xmlbinary_options[] = {
 296         {"base64", XMLBINARY_BASE64, false},
 297         {"hex", XMLBINARY_HEX, false},
 298         {NULL, 0, false}
 299 };
 300
 301 static const struct config_enum_entry xmloption_options[] = {
 302         {"content", XMLOPTION_CONTENT, false},
 303         {"document", XMLOPTION_DOCUMENT, false},
 304         {NULL, 0, false}
 305 };
 306
 307 /*
 308  * Although only "on", "off", and "safe_encoding" are documented, we
 309  * accept all the likely variants of "on" and "off".
 310  */
 311 static const struct config_enum_entry backslash_quote_options[] = {
 312         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 313         {"on", BACKSLASH_QUOTE_ON, false},
 314         {"off", BACKSLASH_QUOTE_OFF, false},
 315         {"true", BACKSLASH_QUOTE_ON, true},
 316         {"false", BACKSLASH_QUOTE_OFF, true},
 317         {"yes", BACKSLASH_QUOTE_ON, true},
 318         {"no", BACKSLASH_QUOTE_OFF, true},
 319         {"1", BACKSLASH_QUOTE_ON, true},
 320         {"0", BACKSLASH_QUOTE_OFF, true},
 321         {NULL, 0, false}
 322 };
 323
 324 /*
 325  * Although only "on", "off", and "partition" are documented, we
 326  * accept all the likely variants of "on" and "off".
 327  */
 328 static const struct config_enum_entry constraint_exclusion_options[] = {
 329         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 330         {"on", CONSTRAINT_EXCLUSION_ON, false},
 331         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 332         {"true", CONSTRAINT_EXCLUSION_ON, true},
 333         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 334         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 335         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 336         {"1", CONSTRAINT_EXCLUSION_ON, true},
 337         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 338         {NULL, 0, false}
 339 };
 340
 341 /*
 342  * Options for enum values stored in other modules
 343  */
 344 extern const struct config_enum_entry sync_method_options[];
 345
 346 /*
 347  * GUC option variables that are exported from this module
 348  */
 349 #ifdef USE_ASSERT_CHECKING
 350 bool            assert_enabled = true;
 351 #else
 352 bool            assert_enabled = false;
 353 #endif
 354 bool            log_duration = false;
 355 bool            Debug_print_plan = false;
 356 bool            Debug_print_parse = false;
 357 bool            Debug_print_rewritten = false;
 358 bool            Debug_pretty_print = true;
 359
 360 bool            log_parser_stats = false;
 361 bool            log_planner_stats = false;
 362 bool            log_executor_stats = false;
 363 bool            log_statement_stats = false;            /* this is sort of all three
 364                                                                                                  * above together */
 365 bool            log_btree_build_stats = false;
 366
 367 bool            check_function_bodies = true;
 368 bool            default_with_oids = false;
 369 bool            SQL_inheritance = true;
 370
 371 bool            Password_encryption = true;
 372
 373 int                     log_min_error_statement = ERROR;
 374 int                     log_min_messages = WARNING;
 375 int                     client_min_messages = NOTICE;
 376 int                     log_min_duration_statement = -1;
 377 int                     log_temp_files = -1;
 378
 379 int                     num_temp_buffers = 1000;
 380
 381 char       *ConfigFileName;
 382 char       *HbaFileName;
 383 char       *IdentFileName;
 384 char       *external_pid_file;
 385
 386 char       *pgstat_temp_directory;
 387
 388 int                     tcp_keepalives_idle;
 389 int                     tcp_keepalives_interval;
 390 int                     tcp_keepalives_count;
 391
 392 /*
 393  * These variables are all dummies that don't do anything, except in some
 394  * cases provide the value for SHOW to display.  The real state is elsewhere
 395  * and is kept in sync by assign_hooks.
 396  */
 397 static char *log_destination_string;
 398
 399 #ifdef HAVE_SYSLOG
 400 static char *syslog_ident_str;
 401 #endif
 402 static bool phony_autocommit;
 403 static bool session_auth_is_superuser;
 404 static double phony_random_seed;
 405 static char *client_encoding_string;
 406 static char *datestyle_string;
 407 static char *locale_collate;
 408 static char *locale_ctype;
 409 static char *server_encoding_string;
 410 static char *server_version_string;
 411 static int      server_version_num;
 412 static char *timezone_string;
 413 static char *log_timezone_string;
 414 static char *timezone_abbreviations_string;
 415 static char *XactIsoLevel_string;
 416 static char *data_directory;
 417 static char *custom_variable_classes;
 418 static int      max_function_args;
 419 static int      max_index_keys;
 420 static int      max_identifier_length;
 421 static int      block_size;
 422 static int      segment_size;
 423 static int      wal_block_size;
 424 static int      wal_segment_size;
 425 static bool integer_datetimes;
 426 static int      effective_io_concurrency;
 427
 428 /* should be static, but commands/variable.c needs to get at these */
 429 char       *role_string;
 430 char       *session_authorization_string;
 431
 432
 433 /*
 434  * Displayable names for context types (enum GucContext)
 435  *
 436  * Note: these strings are deliberately not localized.
 437  */
 438 const char *const GucContext_Names[] =
 439 {
 440          /* PGC_INTERNAL */ "internal",
 441          /* PGC_POSTMASTER */ "postmaster",
 442          /* PGC_SIGHUP */ "sighup",
 443          /* PGC_BACKEND */ "backend",
 444          /* PGC_SUSET */ "superuser",
 445          /* PGC_USERSET */ "user"
 446 };
 447
 448 /*
 449  * Displayable names for source types (enum GucSource)
 450  *
 451  * Note: these strings are deliberately not localized.
 452  */
 453 const char *const GucSource_Names[] =
 454 {
 455          /* PGC_S_DEFAULT */ "default",
 456          /* PGC_S_ENV_VAR */ "environment variable",
 457          /* PGC_S_FILE */ "configuration file",
 458          /* PGC_S_ARGV */ "command line",
 459          /* PGC_S_DATABASE */ "database",
 460          /* PGC_S_USER */ "user",
 461          /* PGC_S_CLIENT */ "client",
 462          /* PGC_S_OVERRIDE */ "override",
 463          /* PGC_S_INTERACTIVE */ "interactive",
 464          /* PGC_S_TEST */ "test",
 465          /* PGC_S_SESSION */ "session"
 466 };
 467
 468 /*
 469  * Displayable names for the groupings defined in enum config_group
 470  */
 471 const char *const config_group_names[] =
 472 {
 473         /* UNGROUPED */
 474         gettext_noop("Ungrouped"),
 475         /* FILE_LOCATIONS */
 476         gettext_noop("File Locations"),
 477         /* CONN_AUTH */
 478         gettext_noop("Connections and Authentication"),
 479         /* CONN_AUTH_SETTINGS */
 480         gettext_noop("Connections and Authentication / Connection Settings"),
 481         /* CONN_AUTH_SECURITY */
 482         gettext_noop("Connections and Authentication / Security and Authentication"),
 483         /* RESOURCES */
 484         gettext_noop("Resource Usage"),
 485         /* RESOURCES_MEM */
 486         gettext_noop("Resource Usage / Memory"),
 487         /* RESOURCES_KERNEL */
 488         gettext_noop("Resource Usage / Kernel Resources"),
 489         /* WAL */
 490         gettext_noop("Write-Ahead Log"),
 491         /* WAL_SETTINGS */
 492         gettext_noop("Write-Ahead Log / Settings"),
 493         /* WAL_CHECKPOINTS */
 494         gettext_noop("Write-Ahead Log / Checkpoints"),
 495         /* QUERY_TUNING */
 496         gettext_noop("Query Tuning"),
 497         /* QUERY_TUNING_METHOD */
 498         gettext_noop("Query Tuning / Planner Method Configuration"),
 499         /* QUERY_TUNING_COST */
 500         gettext_noop("Query Tuning / Planner Cost Constants"),
 501         /* QUERY_TUNING_GEQO */
 502         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 503         /* QUERY_TUNING_OTHER */
 504         gettext_noop("Query Tuning / Other Planner Options"),
 505         /* LOGGING */
 506         gettext_noop("Reporting and Logging"),
 507         /* LOGGING_WHERE */
 508         gettext_noop("Reporting and Logging / Where to Log"),
 509         /* LOGGING_WHEN */
 510         gettext_noop("Reporting and Logging / When to Log"),
 511         /* LOGGING_WHAT */
 512         gettext_noop("Reporting and Logging / What to Log"),
 513         /* STATS */
 514         gettext_noop("Statistics"),
 515         /* STATS_MONITORING */
 516         gettext_noop("Statistics / Monitoring"),
 517         /* STATS_COLLECTOR */
 518         gettext_noop("Statistics / Query and Index Statistics Collector"),
 519         /* AUTOVACUUM */
 520         gettext_noop("Autovacuum"),
 521         /* CLIENT_CONN */
 522         gettext_noop("Client Connection Defaults"),
 523         /* CLIENT_CONN_STATEMENT */
 524         gettext_noop("Client Connection Defaults / Statement Behavior"),
 525         /* CLIENT_CONN_LOCALE */
 526         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 527         /* CLIENT_CONN_OTHER */
 528         gettext_noop("Client Connection Defaults / Other Defaults"),
 529         /* LOCK_MANAGEMENT */
 530         gettext_noop("Lock Management"),
 531         /* COMPAT_OPTIONS */
 532         gettext_noop("Version and Platform Compatibility"),
 533         /* COMPAT_OPTIONS_PREVIOUS */
 534         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 535         /* COMPAT_OPTIONS_CLIENT */
 536         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 537         /* PRESET_OPTIONS */
 538         gettext_noop("Preset Options"),
 539         /* CUSTOM_OPTIONS */
 540         gettext_noop("Customized Options"),
 541         /* DEVELOPER_OPTIONS */
 542         gettext_noop("Developer Options"),
 543         /* help_config wants this array to be null-terminated */
 544         NULL
 545 };
 546
 547 /*
 548  * Displayable names for GUC variable types (enum config_type)
 549  *
 550  * Note: these strings are deliberately not localized.
 551  */
 552 const char *const config_type_names[] =
 553 {
 554          /* PGC_BOOL */ "bool",
 555          /* PGC_INT */ "integer",
 556          /* PGC_REAL */ "real",
 557          /* PGC_STRING */ "string",
 558          /* PGC_ENUM */ "enum"
 559 };
 560
 561
 562 /*
 563  * Contents of GUC tables
 564  *
 565  * See src/backend/utils/misc/README for design notes.
 566  *
 567  * TO ADD AN OPTION:
 568  *
 569  * 1. Declare a global variable of type bool, int, double, or char*
 570  *        and make use of it.
 571  *
 572  * 2. Decide at what times it's safe to set the option. See guc.h for
 573  *        details.
 574  *
 575  * 3. Decide on a name, a default value, upper and lower bounds (if
 576  *        applicable), etc.
 577  *
 578  * 4. Add a record below.
 579  *
 580  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 581  *        appropriate.
 582  *
 583  * 6. Don't forget to document the option (at least in config.sgml).
 584  *
 585  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 586  *        it is not single quoted at dump time.
 587  */
 588
 589
 590 /******** option records follow ********/
 591
 592 static struct config_bool ConfigureNamesBool[] =
 593 {
 594         {
 595                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 596                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 597                         NULL
 598                 },
 599                 &enable_seqscan,
 600                 true, NULL, NULL
 601         },
 602         {
 603                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 604                         gettext_noop("Enables the planner's use of index-scan plans."),
 605                         NULL
 606                 },
 607                 &enable_indexscan,
 608                 true, NULL, NULL
 609         },
 610         {
 611                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 612                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 613                         NULL
 614                 },
 615                 &enable_bitmapscan,
 616                 true, NULL, NULL
 617         },
 618         {
 619                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 620                         gettext_noop("Enables the planner's use of TID scan plans."),
 621                         NULL
 622                 },
 623                 &enable_tidscan,
 624                 true, NULL, NULL
 625         },
 626         {
 627                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 628                         gettext_noop("Enables the planner's use of explicit sort steps."),
 629                         NULL
 630                 },
 631                 &enable_sort,
 632                 true, NULL, NULL
 633         },
 634         {
 635                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 636                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 637                         NULL
 638                 },
 639                 &enable_hashagg,
 640                 true, NULL, NULL
 641         },
 642         {
 643                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 644                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 645                         NULL
 646                 },
 647                 &enable_nestloop,
 648                 true, NULL, NULL
 649         },
 650         {
 651                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 652                         gettext_noop("Enables the planner's use of merge join plans."),
 653                         NULL
 654                 },
 655                 &enable_mergejoin,
 656                 true, NULL, NULL
 657         },
 658         {
 659                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 660                         gettext_noop("Enables the planner's use of hash join plans."),
 661                         NULL
 662                 },
 663                 &enable_hashjoin,
 664                 true, NULL, NULL
 665         },
 666         {
 667                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 668                         gettext_noop("Enables genetic query optimization."),
 669                         gettext_noop("This algorithm attempts to do planning without "
 670                                                  "exhaustive searching.")
 671                 },
 672                 &enable_geqo,
 673                 true, NULL, NULL
 674         },
 675         {
 676                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 677                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 678                         gettext_noop("Shows whether the current user is a superuser."),
 679                         NULL,
 680                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 681                 },
 682                 &session_auth_is_superuser,
 683                 false, NULL, NULL
 684         },
 685         {
 686                 {"bonjour", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
 687                         gettext_noop("Enables advertising the server via Bonjour."),
 688                         NULL
 689                 },
 690                 &enable_bonjour,
 691                 false, assign_bonjour, NULL
 692         },
 693         {
 694                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 695                         gettext_noop("Enables SSL connections."),
 696                         NULL
 697                 },
 698                 &EnableSSL,
 699                 false, assign_ssl, NULL
 700         },
 701         {
 702                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 703                         gettext_noop("Forces synchronization of updates to disk."),
 704                         gettext_noop("The server will use the fsync() system call in several places to make "
 705                         "sure that updates are physically written to disk. This insures "
 706                                                  "that a database cluster will recover to a consistent state after "
 707                                                  "an operating system or hardware crash.")
 708                 },
 709                 &enableFsync,
 710                 true, NULL, NULL
 711         },
 712         {
 713                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 714                         gettext_noop("Sets immediate fsync at commit."),
 715                         NULL
 716                 },
 717                 &XactSyncCommit,
 718                 true, NULL, NULL
 719         },
 720         {
 721                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 722                         gettext_noop("Continues processing past damaged page headers."),
 723                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 724                                 "report an error, aborting the current transaction. Setting "
 725                                                  "zero_damaged_pages to true causes the system to instead report a "
 726                                                  "warning, zero out the damaged page, and continue processing. This "
 727                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 728                         GUC_NOT_IN_SAMPLE
 729                 },
 730                 &zero_damaged_pages,
 731                 false, NULL, NULL
 732         },
 733         {
 734                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 735                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 736                         gettext_noop("A page write in process during an operating system crash might be "
 737                                                  "only partially written to disk.  During recovery, the row changes "
 738                           "stored in WAL are not enough to recover.  This option writes "
 739                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 740                                                  "is possible.")
 741                 },
 742                 &fullPageWrites,
 743                 true, NULL, NULL
 744         },
 745         {
 746                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHERE,
 747                         gettext_noop("Runs the server silently."),
 748                         gettext_noop("If this parameter is set, the server will automatically run in the "
 749                                  "background and any controlling terminals are dissociated.")
 750                 },
 751                 &SilentMode,
 752                 false, NULL, NULL
 753         },
 754         {
 755                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 756                         gettext_noop("Logs each checkpoint."),
 757                         NULL
 758                 },
 759                 &log_checkpoints,
 760                 false, NULL, NULL
 761         },
 762         {
 763                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 764                         gettext_noop("Logs each successful connection."),
 765                         NULL
 766                 },
 767                 &Log_connections,
 768                 false, NULL, NULL
 769         },
 770         {
 771                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 772                         gettext_noop("Logs end of a session, including duration."),
 773                         NULL
 774                 },
 775                 &Log_disconnections,
 776                 false, NULL, NULL
 777         },
 778         {
 779                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 780                         gettext_noop("Turns on various assertion checks."),
 781                         gettext_noop("This is a debugging aid."),
 782                         GUC_NOT_IN_SAMPLE
 783                 },
 784                 &assert_enabled,
 785 #ifdef USE_ASSERT_CHECKING
 786                 true,
 787 #else
 788                 false,
 789 #endif
 790                 assign_debug_assertions, NULL
 791         },
 792         {
 793                 /* currently undocumented, so don't show in SHOW ALL */
 794                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 795                         gettext_noop("No description available."),
 796                         NULL,
 797                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 798                 },
 799                 &ExitOnAnyError,
 800                 false, NULL, NULL
 801         },
 802         {
 803                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 804                         gettext_noop("Logs the duration of each completed SQL statement."),
 805                         NULL
 806                 },
 807                 &log_duration,
 808                 false, NULL, NULL
 809         },
 810         {
 811                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 812                         gettext_noop("Logs each query's parse tree."),
 813                         NULL
 814                 },
 815                 &Debug_print_parse,
 816                 false, NULL, NULL
 817         },
 818         {
 819                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 820                         gettext_noop("Logs each query's rewritten parse tree."),
 821                         NULL
 822                 },
 823                 &Debug_print_rewritten,
 824                 false, NULL, NULL
 825         },
 826         {
 827                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 828                         gettext_noop("Logs each query's execution plan."),
 829                         NULL
 830                 },
 831                 &Debug_print_plan,
 832                 false, NULL, NULL
 833         },
 834         {
 835                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 836                         gettext_noop("Indents parse and plan tree displays."),
 837                         NULL
 838                 },
 839                 &Debug_pretty_print,
 840                 true, NULL, NULL
 841         },
 842         {
 843                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 844                         gettext_noop("Writes parser performance statistics to the server log."),
 845                         NULL
 846                 },
 847                 &log_parser_stats,
 848                 false, assign_stage_log_stats, NULL
 849         },
 850         {
 851                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 852                         gettext_noop("Writes planner performance statistics to the server log."),
 853                         NULL
 854                 },
 855                 &log_planner_stats,
 856                 false, assign_stage_log_stats, NULL
 857         },
 858         {
 859                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 860                         gettext_noop("Writes executor performance statistics to the server log."),
 861                         NULL
 862                 },
 863                 &log_executor_stats,
 864                 false, assign_stage_log_stats, NULL
 865         },
 866         {
 867                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 868                         gettext_noop("Writes cumulative performance statistics to the server log."),
 869                         NULL
 870                 },
 871                 &log_statement_stats,
 872                 false, assign_log_stats, NULL
 873         },
 874 #ifdef BTREE_BUILD_STATS
 875         {
 876                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 877                         gettext_noop("No description available."),
 878                         NULL,
 879                         GUC_NOT_IN_SAMPLE
 880                 },
 881                 &log_btree_build_stats,
 882                 false, NULL, NULL
 883         },
 884 #endif
 885
 886         {
 887                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 888                         gettext_noop("Collects information about executing commands."),
 889                         gettext_noop("Enables the collection of information on the currently "
 890                                                  "executing command of each session, along with "
 891                                                  "the time at which that command began execution.")
 892                 },
 893                 &pgstat_track_activities,
 894                 true, NULL, NULL
 895         },
 896         {
 897                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 898                         gettext_noop("Collects statistics on database activity."),
 899                         NULL
 900                 },
 901                 &pgstat_track_counts,
 902                 true, NULL, NULL
 903         },
 904
 905         {
 906                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 907                         gettext_noop("Updates the process title to show the active SQL command."),
 908                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 909                 },
 910                 &update_process_title,
 911                 true, NULL, NULL
 912         },
 913
 914         {
 915                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 916                         gettext_noop("Starts the autovacuum subprocess."),
 917                         NULL
 918                 },
 919                 &autovacuum_start_daemon,
 920                 true, NULL, NULL
 921         },
 922
 923         {
 924                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 925                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 926                         NULL,
 927                         GUC_NOT_IN_SAMPLE
 928                 },
 929                 &Trace_notify,
 930                 false, NULL, NULL
 931         },
 932
 933 #ifdef LOCK_DEBUG
 934         {
 935                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 936                         gettext_noop("No description available."),
 937                         NULL,
 938                         GUC_NOT_IN_SAMPLE
 939                 },
 940                 &Trace_locks,
 941                 false, NULL, NULL
 942         },
 943         {
 944                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 945                         gettext_noop("No description available."),
 946                         NULL,
 947                         GUC_NOT_IN_SAMPLE
 948                 },
 949                 &Trace_userlocks,
 950                 false, NULL, NULL
 951         },
 952         {
 953                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 954                         gettext_noop("No description available."),
 955                         NULL,
 956                         GUC_NOT_IN_SAMPLE
 957                 },
 958                 &Trace_lwlocks,
 959                 false, NULL, NULL
 960         },
 961         {
 962                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 963                         gettext_noop("No description available."),
 964                         NULL,
 965                         GUC_NOT_IN_SAMPLE
 966                 },
 967                 &Debug_deadlocks,
 968                 false, NULL, NULL
 969         },
 970 #endif
 971
 972         {
 973                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 974                         gettext_noop("Logs long lock waits."),
 975                         NULL
 976                 },
 977                 &log_lock_waits,
 978                 false, NULL, NULL
 979         },
 980
 981         {
 982                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 983                         gettext_noop("Logs the host name in the connection logs."),
 984                         gettext_noop("By default, connection logs only show the IP address "
 985                                                  "of the connecting host. If you want them to show the host name you "
 986                           "can turn this on, but depending on your host name resolution "
 987                            "setup it might impose a non-negligible performance penalty.")
 988                 },
 989                 &log_hostname,
 990                 false, NULL, NULL
 991         },
 992         {
 993                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 994                         gettext_noop("Causes subtables to be included by default in various commands."),
 995                         NULL
 996                 },
 997                 &SQL_inheritance,
 998                 true, NULL, NULL
 999         },
1000         {
1001                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
1002                         gettext_noop("Encrypt passwords."),
1003                         gettext_noop("When a password is specified in CREATE USER or "
1004                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
1005                                                  "this parameter determines whether the password is to be encrypted.")
1006                 },
1007                 &Password_encryption,
1008                 true, NULL, NULL
1009         },
1010         {
1011                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
1012                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
1013                         gettext_noop("When turned on, expressions of the form expr = NULL "
1014                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
1015                                 "return true if expr evaluates to the null value, and false "
1016                            "otherwise. The correct behavior of expr = NULL is to always "
1017                                                  "return null (unknown).")
1018                 },
1019                 &Transform_null_equals,
1020                 false, NULL, NULL
1021         },
1022         {
1023                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1024                         gettext_noop("Enables per-database user names."),
1025                         NULL
1026                 },
1027                 &Db_user_namespace,
1028                 false, NULL, NULL
1029         },
1030         {
1031                 /* only here for backwards compatibility */
1032                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1033                         gettext_noop("This parameter doesn't do anything."),
1034                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1035                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1036                 },
1037                 &phony_autocommit,
1038                 true, assign_phony_autocommit, NULL
1039         },
1040         {
1041                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1042                         gettext_noop("Sets the default read-only status of new transactions."),
1043                         NULL
1044                 },
1045                 &DefaultXactReadOnly,
1046                 false, NULL, NULL
1047         },
1048         {
1049                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1050                         gettext_noop("Sets the current transaction's read-only status."),
1051                         NULL,
1052                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1053                 },
1054                 &XactReadOnly,
1055                 false, assign_transaction_read_only, NULL
1056         },
1057         {
1058                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1059                         gettext_noop("Automatically adds missing table references to FROM clauses."),
1060                         NULL
1061                 },
1062                 &add_missing_from,
1063                 false, NULL, NULL
1064         },
1065         {
1066                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1067                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1068                         NULL
1069                 },
1070                 &check_function_bodies,
1071                 true, NULL, NULL
1072         },
1073         {
1074                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1075                         gettext_noop("Enable input of NULL elements in arrays."),
1076                         gettext_noop("When turned on, unquoted NULL in an array input "
1077                                                  "value means a null value; "
1078                                                  "otherwise it is taken literally.")
1079                 },
1080                 &Array_nulls,
1081                 true, NULL, NULL
1082         },
1083         {
1084                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1085                         gettext_noop("Create new tables with OIDs by default."),
1086                         NULL
1087                 },
1088                 &default_with_oids,
1089                 false, NULL, NULL
1090         },
1091         {
1092                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1093                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1094                         NULL
1095                 },
1096                 &Logging_collector,
1097                 false, NULL, NULL
1098         },
1099         {
1100                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1101                         gettext_noop("Truncate existing log files of same name during log rotation."),
1102                         NULL
1103                 },
1104                 &Log_truncate_on_rotation,
1105                 false, NULL, NULL
1106         },
1107
1108 #ifdef TRACE_SORT
1109         {
1110                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1111                         gettext_noop("Emit information about resource usage in sorting."),
1112                         NULL,
1113                         GUC_NOT_IN_SAMPLE
1114                 },
1115                 &trace_sort,
1116                 false, NULL, NULL
1117         },
1118 #endif
1119
1120 #ifdef TRACE_SYNCSCAN
1121         /* this is undocumented because not exposed in a standard build */
1122         {
1123                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1124                         gettext_noop("Generate debugging output for synchronized scanning."),
1125                         NULL,
1126                         GUC_NOT_IN_SAMPLE
1127                 },
1128                 &trace_syncscan,
1129                 false, NULL, NULL
1130         },
1131 #endif
1132
1133 #ifdef DEBUG_BOUNDED_SORT
1134         /* this is undocumented because not exposed in a standard build */
1135         {
1136                 {
1137                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1138                         gettext_noop("Enable bounded sorting using heap sort."),
1139                         NULL,
1140                         GUC_NOT_IN_SAMPLE
1141                 },
1142                 &optimize_bounded_sort,
1143                 true, NULL, NULL
1144         },
1145 #endif
1146
1147 #ifdef WAL_DEBUG
1148         {
1149                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1150                         gettext_noop("Emit WAL-related debugging output."),
1151                         NULL,
1152                         GUC_NOT_IN_SAMPLE
1153                 },
1154                 &XLOG_DEBUG,
1155                 false, NULL, NULL
1156         },
1157 #endif
1158
1159         {
1160                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1161                         gettext_noop("Datetimes are integer based."),
1162                         NULL,
1163                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1164                 },
1165                 &integer_datetimes,
1166 #ifdef HAVE_INT64_TIMESTAMP
1167                 true, NULL, NULL
1168 #else
1169                 false, NULL, NULL
1170 #endif
1171         },
1172
1173         {
1174                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1175                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1176                         NULL
1177                 },
1178                 &pg_krb_caseins_users,
1179                 false, NULL, NULL
1180         },
1181
1182         {
1183                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1184                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1185                         NULL
1186                 },
1187                 &escape_string_warning,
1188                 true, NULL, NULL
1189         },
1190
1191         {
1192                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1193                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1194                         NULL,
1195                         GUC_REPORT
1196                 },
1197                 &standard_conforming_strings,
1198                 false, NULL, NULL
1199         },
1200
1201         {
1202                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1203                         gettext_noop("Enable synchronized sequential scans."),
1204                         NULL
1205                 },
1206                 &synchronize_seqscans,
1207                 true, NULL, NULL
1208         },
1209
1210         {
1211                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1212                         gettext_noop("Allows archiving of WAL files using archive_command."),
1213                         NULL
1214                 },
1215                 &XLogArchiveMode,
1216                 false, NULL, NULL
1217         },
1218
1219         {
1220                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1221                         gettext_noop("Allows modifications of the structure of system tables."),
1222                         NULL,
1223                         GUC_NOT_IN_SAMPLE
1224                 },
1225                 &allowSystemTableMods,
1226                 false, NULL, NULL
1227         },
1228
1229         {
1230                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1231                         gettext_noop("Disables reading from system indexes."),
1232                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1233                                                  "to use.  The worst consequence is slowness."),
1234                         GUC_NOT_IN_SAMPLE
1235                 },
1236                 &IgnoreSystemIndexes,
1237                 false, NULL, NULL
1238         },
1239
1240         /* End-of-list marker */
1241         {
1242                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1243         }
1244 };
1245
1246
1247 static struct config_int ConfigureNamesInt[] =
1248 {
1249         {
1250                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1251                         gettext_noop("Forces a switch to the next xlog file if a "
1252                                                  "new file has not been started within N seconds."),
1253                         NULL,
1254                         GUC_UNIT_S
1255                 },
1256                 &XLogArchiveTimeout,
1257                 0, 0, INT_MAX, NULL, NULL
1258         },
1259         {
1260                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1261                         gettext_noop("Waits N seconds on connection startup after authentication."),
1262                         gettext_noop("This allows attaching a debugger to the process."),
1263                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1264                 },
1265                 &PostAuthDelay,
1266                 0, 0, INT_MAX, NULL, NULL
1267         },
1268         {
1269                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1270                         gettext_noop("Sets the default statistics target."),
1271                         gettext_noop("This applies to table columns that have not had a "
1272                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1273                 },
1274                 &default_statistics_target,
1275                 100, 1, 10000, NULL, NULL
1276         },
1277         {
1278                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1279                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1280                                                  "are not collapsed."),
1281                         gettext_noop("The planner will merge subqueries into upper "
1282                                 "queries if the resulting FROM list would have no more than "
1283                                                  "this many items.")
1284                 },
1285                 &from_collapse_limit,
1286                 8, 1, INT_MAX, NULL, NULL
1287         },
1288         {
1289                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1290                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1291                                                  "constructs are not flattened."),
1292                         gettext_noop("The planner will flatten explicit JOIN "
1293                                                  "constructs into lists of FROM items whenever a "
1294                                                  "list of no more than this many items would result.")
1295                 },
1296                 &join_collapse_limit,
1297                 8, 1, INT_MAX, NULL, NULL
1298         },
1299         {
1300                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1301                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1302                         NULL
1303                 },
1304                 &geqo_threshold,
1305                 12, 2, INT_MAX, NULL, NULL
1306         },
1307         {
1308                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1309                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1310                         NULL
1311                 },
1312                 &Geqo_effort,
1313                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1314         },
1315         {
1316                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1317                         gettext_noop("GEQO: number of individuals in the population."),
1318                         gettext_noop("Zero selects a suitable default value.")
1319                 },
1320                 &Geqo_pool_size,
1321                 0, 0, INT_MAX, NULL, NULL
1322         },
1323         {
1324                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1325                         gettext_noop("GEQO: number of iterations of the algorithm."),
1326                         gettext_noop("Zero selects a suitable default value.")
1327                 },
1328                 &Geqo_generations,
1329                 0, 0, INT_MAX, NULL, NULL
1330         },
1331
1332         {
1333                 /* This is PGC_SIGHUP so all backends have the same value. */
1334                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1335                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1336                         NULL,
1337                         GUC_UNIT_MS
1338                 },
1339                 &DeadlockTimeout,
1340                 1000, 1, INT_MAX / 1000, NULL, NULL
1341         },
1342
1343         /*
1344          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1345          * 4*MaxBackends without any overflow check.  This check is made in
1346          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1347          * plus autovacuum_max_workers plus one (for the autovacuum launcher).
1348          *
1349          * Likewise we have to limit NBuffers to INT_MAX/2.
1350          */
1351         {
1352                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1353                         gettext_noop("Sets the maximum number of concurrent connections."),
1354                         NULL
1355                 },
1356                 &MaxConnections,
1357                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1358         },
1359
1360         {
1361                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1362                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1363                         NULL
1364                 },
1365                 &ReservedBackends,
1366                 3, 0, INT_MAX / 4, NULL, NULL
1367         },
1368
1369         {
1370                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1371                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1372                         NULL,
1373                         GUC_UNIT_BLOCKS
1374                 },
1375                 &NBuffers,
1376                 1024, 16, INT_MAX / 2, NULL, NULL
1377         },
1378
1379         {
1380                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1381                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1382                         NULL,
1383                         GUC_UNIT_BLOCKS
1384                 },
1385                 &num_temp_buffers,
1386                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1387         },
1388
1389         {
1390                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1391                         gettext_noop("Sets the TCP port the server listens on."),
1392                         NULL
1393                 },
1394                 &PostPortNumber,
1395                 DEF_PGPORT, 1, 65535, NULL, NULL
1396         },
1397
1398         {
1399                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1400                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1401                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1402                                                  "permission set. The parameter value is expected to be a numeric mode "
1403                                                  "specification in the form accepted by the chmod and umask system "
1404                                                  "calls. (To use the customary octal format the number must start with "
1405                                                  "a 0 (zero).)")
1406                 },
1407                 &Unix_socket_permissions,
1408                 0777, 0000, 0777, NULL, NULL
1409         },
1410
1411         {
1412                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1413                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1414                         gettext_noop("This much memory can be used by each internal "
1415                                                  "sort operation and hash table before switching to "
1416                                                  "temporary disk files."),
1417                         GUC_UNIT_KB
1418                 },
1419                 &work_mem,
1420                 1024, 64, MAX_KILOBYTES, NULL, NULL
1421         },
1422
1423         {
1424                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1425                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1426                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1427                         GUC_UNIT_KB
1428                 },
1429                 &maintenance_work_mem,
1430                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1431         },
1432
1433         {
1434                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1435                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1436                         NULL,
1437                         GUC_UNIT_KB
1438                 },
1439                 &max_stack_depth,
1440                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1441         },
1442
1443         {
1444                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1445                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1446                         NULL
1447                 },
1448                 &VacuumCostPageHit,
1449                 1, 0, 10000, NULL, NULL
1450         },
1451
1452         {
1453                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1454                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1455                         NULL
1456                 },
1457                 &VacuumCostPageMiss,
1458                 10, 0, 10000, NULL, NULL
1459         },
1460
1461         {
1462                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1463                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1464                         NULL
1465                 },
1466                 &VacuumCostPageDirty,
1467                 20, 0, 10000, NULL, NULL
1468         },
1469
1470         {
1471                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1472                         gettext_noop("Vacuum cost amount available before napping."),
1473                         NULL
1474                 },
1475                 &VacuumCostLimit,
1476                 200, 1, 10000, NULL, NULL
1477         },
1478
1479         {
1480                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1481                         gettext_noop("Vacuum cost delay in milliseconds."),
1482                         NULL,
1483                         GUC_UNIT_MS
1484                 },
1485                 &VacuumCostDelay,
1486                 0, 0, 100, NULL, NULL
1487         },
1488
1489         {
1490                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1491                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1492                         NULL,
1493                         GUC_UNIT_MS
1494                 },
1495                 &autovacuum_vac_cost_delay,
1496                 20, -1, 100, NULL, NULL
1497         },
1498
1499         {
1500                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1501                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1502                         NULL
1503                 },
1504                 &autovacuum_vac_cost_limit,
1505                 -1, -1, 10000, NULL, NULL
1506         },
1507
1508         {
1509                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1510                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1511                         NULL
1512                 },
1513                 &max_files_per_process,
1514                 1000, 25, INT_MAX, NULL, NULL
1515         },
1516
1517         {
1518                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1519                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1520                         NULL
1521                 },
1522                 &max_prepared_xacts,
1523                 0, 0, INT_MAX / 4, NULL, NULL
1524         },
1525
1526 #ifdef LOCK_DEBUG
1527         {
1528                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1529                         gettext_noop("No description available."),
1530                         NULL,
1531                         GUC_NOT_IN_SAMPLE
1532                 },
1533                 &Trace_lock_oidmin,
1534                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1535         },
1536         {
1537                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1538                         gettext_noop("No description available."),
1539                         NULL,
1540                         GUC_NOT_IN_SAMPLE
1541                 },
1542                 &Trace_lock_table,
1543                 0, 0, INT_MAX, NULL, NULL
1544         },
1545 #endif
1546
1547         {
1548                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1549                         gettext_noop("Sets the maximum allowed duration of any statement."),
1550                         gettext_noop("A value of 0 turns off the timeout."),
1551                         GUC_UNIT_MS
1552                 },
1553                 &StatementTimeout,
1554                 0, 0, INT_MAX, NULL, NULL
1555         },
1556
1557         {
1558                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1559                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1560                         NULL
1561                 },
1562                 &vacuum_freeze_min_age,
1563                 50000000, 0, 1000000000, NULL, NULL
1564         },
1565
1566         {
1567                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1568                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1569                         NULL
1570                 },
1571                 &vacuum_freeze_table_age,
1572                 150000000, 0, 2000000000, NULL, NULL
1573         },
1574
1575         {
1576                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1577                         gettext_noop("Sets the maximum number of locks per transaction."),
1578                         gettext_noop("The shared lock table is sized on the assumption that "
1579                           "at most max_locks_per_transaction * max_connections distinct "
1580                                                  "objects will need to be locked at any one time.")
1581                 },
1582                 &max_locks_per_xact,
1583                 64, 10, INT_MAX, NULL, NULL
1584         },
1585
1586         {
1587                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1588                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1589                         NULL,
1590                         GUC_UNIT_S
1591                 },
1592                 &AuthenticationTimeout,
1593                 60, 1, 600, NULL, NULL
1594         },
1595
1596         {
1597                 /* Not for general use */
1598                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1599                         gettext_noop("Waits N seconds on connection startup before authentication."),
1600                         gettext_noop("This allows attaching a debugger to the process."),
1601                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1602                 },
1603                 &PreAuthDelay,
1604                 0, 0, 60, NULL, NULL
1605         },
1606
1607         {
1608                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1609                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1610                         NULL
1611                 },
1612                 &CheckPointSegments,
1613                 3, 1, INT_MAX, NULL, NULL
1614         },
1615
1616         {
1617                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1618                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1619                         NULL,
1620                         GUC_UNIT_S
1621                 },
1622                 &CheckPointTimeout,
1623                 300, 30, 3600, NULL, NULL
1624         },
1625
1626         {
1627                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1628                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1629                                                  "frequently than this."),
1630                         gettext_noop("Write a message to the server log if checkpoints "
1631                         "caused by the filling of checkpoint segment files happens more "
1632                                                  "frequently than this number of seconds. Zero turns off the warning."),
1633                         GUC_UNIT_S
1634                 },
1635                 &CheckPointWarning,
1636                 30, 0, INT_MAX, NULL, NULL
1637         },
1638
1639         {
1640                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1641                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1642                         NULL,
1643                         GUC_UNIT_XBLOCKS
1644                 },
1645                 &XLOGbuffers,
1646                 8, 4, INT_MAX, NULL, NULL
1647         },
1648
1649         {
1650                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1651                         gettext_noop("WAL writer sleep time between WAL flushes."),
1652                         NULL,
1653                         GUC_UNIT_MS
1654                 },
1655                 &WalWriterDelay,
1656                 200, 1, 10000, NULL, NULL
1657         },
1658
1659         {
1660                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1661                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1662                                                  "flushing WAL to disk."),
1663                         NULL
1664                 },
1665                 &CommitDelay,
1666                 0, 0, 100000, NULL, NULL
1667         },
1668
1669         {
1670                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1671                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1672                                                  "commit_delay."),
1673                         NULL
1674                 },
1675                 &CommitSiblings,
1676                 5, 1, 1000, NULL, NULL
1677         },
1678
1679         {
1680                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1681                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1682                         gettext_noop("This affects real, double precision, and geometric data types. "
1683                          "The parameter value is added to the standard number of digits "
1684                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1685                 },
1686                 &extra_float_digits,
1687                 0, -15, 2, NULL, NULL
1688         },
1689
1690         {
1691                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1692                         gettext_noop("Sets the minimum execution time above which "
1693                                                  "statements will be logged."),
1694                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1695                         GUC_UNIT_MS
1696                 },
1697                 &log_min_duration_statement,
1698                 -1, -1, INT_MAX / 1000, NULL, NULL
1699         },
1700
1701         {
1702                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1703                         gettext_noop("Sets the minimum execution time above which "
1704                                                  "autovacuum actions will be logged."),
1705                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1706                         GUC_UNIT_MS
1707                 },
1708                 &Log_autovacuum_min_duration,
1709                 -1, -1, INT_MAX / 1000, NULL, NULL
1710         },
1711
1712         {
1713                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1714                         gettext_noop("Background writer sleep time between rounds."),
1715                         NULL,
1716                         GUC_UNIT_MS
1717                 },
1718                 &BgWriterDelay,
1719                 200, 10, 10000, NULL, NULL
1720         },
1721
1722         {
1723                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1724                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1725                         NULL
1726                 },
1727                 &bgwriter_lru_maxpages,
1728                 100, 0, 1000, NULL, NULL
1729         },
1730
1731         {
1732                 {"effective_io_concurrency",
1733 #ifdef USE_PREFETCH
1734                         PGC_USERSET,
1735 #else
1736                         PGC_INTERNAL,
1737 #endif
1738                         RESOURCES,
1739                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
1740                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
1741                 },
1742                 &effective_io_concurrency,
1743 #ifdef USE_PREFETCH
1744                 1, 0, 1000,
1745 #else
1746                 0, 0, 0,
1747 #endif
1748                 assign_effective_io_concurrency, NULL
1749         },
1750
1751         {
1752                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1753                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1754                         NULL,
1755                         GUC_UNIT_MIN
1756                 },
1757                 &Log_RotationAge,
1758                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1759         },
1760
1761         {
1762                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1763                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1764                         NULL,
1765                         GUC_UNIT_KB
1766                 },
1767                 &Log_RotationSize,
1768                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1769         },
1770
1771         {
1772                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1773                         gettext_noop("Shows the maximum number of function arguments."),
1774                         NULL,
1775                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1776                 },
1777                 &max_function_args,
1778                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1779         },
1780
1781         {
1782                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1783                         gettext_noop("Shows the maximum number of index keys."),
1784                         NULL,
1785                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1786                 },
1787                 &max_index_keys,
1788                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1789         },
1790
1791         {
1792                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1793                         gettext_noop("Shows the maximum identifier length."),
1794                         NULL,
1795                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1796                 },
1797                 &max_identifier_length,
1798                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1799         },
1800
1801         {
1802                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1803                         gettext_noop("Shows the size of a disk block."),
1804                         NULL,
1805                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1806                 },
1807                 &block_size,
1808                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1809         },
1810
1811         {
1812                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1813                         gettext_noop("Shows the number of pages per disk file."),
1814                         NULL,
1815                         GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1816                 },
1817                 &segment_size,
1818                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1819         },
1820
1821         {
1822                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1823                         gettext_noop("Shows the block size in the write ahead log."),
1824                         NULL,
1825                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1826                 },
1827                 &wal_block_size,
1828                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1829         },
1830
1831         {
1832                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1833                         gettext_noop("Shows the number of pages per write ahead log segment."),
1834                         NULL,
1835                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1836                 },
1837                 &wal_segment_size,
1838                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1839                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1840                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1841                 NULL, NULL
1842         },
1843
1844         {
1845                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1846                         gettext_noop("Time to sleep between autovacuum runs."),
1847                         NULL,
1848                         GUC_UNIT_S
1849                 },
1850                 &autovacuum_naptime,
1851                 60, 1, INT_MAX / 1000, NULL, NULL
1852         },
1853         {
1854                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1855                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1856                         NULL
1857                 },
1858                 &autovacuum_vac_thresh,
1859                 50, 0, INT_MAX, NULL, NULL
1860         },
1861         {
1862                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1863                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1864                         NULL
1865                 },
1866                 &autovacuum_anl_thresh,
1867                 50, 0, INT_MAX, NULL, NULL
1868         },
1869         {
1870                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1871                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1872                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1873                         NULL
1874                 },
1875                 &autovacuum_freeze_max_age,
1876                 /* see pg_resetxlog if you change the upper-limit value */
1877                 200000000, 100000000, 2000000000, NULL, NULL
1878         },
1879         {
1880                 /* see max_connections */
1881                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1882                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1883                         NULL
1884                 },
1885                 &autovacuum_max_workers,
1886                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1887         },
1888
1889         {
1890                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1891                         gettext_noop("Time between issuing TCP keepalives."),
1892                         gettext_noop("A value of 0 uses the system default."),
1893                         GUC_UNIT_S
1894                 },
1895                 &tcp_keepalives_idle,
1896                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1897         },
1898
1899         {
1900                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1901                         gettext_noop("Time between TCP keepalive retransmits."),
1902                         gettext_noop("A value of 0 uses the system default."),
1903                         GUC_UNIT_S
1904                 },
1905                 &tcp_keepalives_interval,
1906                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1907         },
1908
1909         {
1910                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1911                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1912                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1913                                                  "lost before a connection is considered dead. A value of 0 uses the "
1914                                                  "system default."),
1915                 },
1916                 &tcp_keepalives_count,
1917                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1918         },
1919
1920         {
1921                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1922                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1923                         NULL,
1924                         0
1925                 },
1926                 &GinFuzzySearchLimit,
1927                 0, 0, INT_MAX, NULL, NULL
1928         },
1929
1930         {
1931                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1932                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1933                         gettext_noop("That is, the portion of the kernel's disk cache that "
1934                                                  "will be used for PostgreSQL data files. This is measured in disk "
1935                                                  "pages, which are normally 8 kB each."),
1936                         GUC_UNIT_BLOCKS,
1937                 },
1938                 &effective_cache_size,
1939                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1940         },
1941
1942         {
1943                 /* Can't be set in postgresql.conf */
1944                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1945                         gettext_noop("Shows the server version as an integer."),
1946                         NULL,
1947                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1948                 },
1949                 &server_version_num,
1950                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1951         },
1952
1953         {
1954                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1955                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1956                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1957                         GUC_UNIT_KB
1958                 },
1959                 &log_temp_files,
1960                 -1, -1, INT_MAX, NULL, NULL
1961         },
1962
1963         {
1964                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1965                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1966                         NULL,
1967                 },
1968                 &pgstat_track_activity_query_size,
1969                 1024, 100, 102400, NULL, NULL
1970         },
1971
1972         /* End-of-list marker */
1973         {
1974                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1975         }
1976 };
1977
1978
1979 static struct config_real ConfigureNamesReal[] =
1980 {
1981         {
1982                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1983                         gettext_noop("Sets the planner's estimate of the cost of a "
1984                                                  "sequentially fetched disk page."),
1985                         NULL
1986                 },
1987                 &seq_page_cost,
1988                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1989         },
1990         {
1991                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1992                         gettext_noop("Sets the planner's estimate of the cost of a "
1993                                                  "nonsequentially fetched disk page."),
1994                         NULL
1995                 },
1996                 &random_page_cost,
1997                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1998         },
1999         {
2000                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2001                         gettext_noop("Sets the planner's estimate of the cost of "
2002                                                  "processing each tuple (row)."),
2003                         NULL
2004                 },
2005                 &cpu_tuple_cost,
2006                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
2007         },
2008         {
2009                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2010                         gettext_noop("Sets the planner's estimate of the cost of "
2011                                                  "processing each index entry during an index scan."),
2012                         NULL
2013                 },
2014                 &cpu_index_tuple_cost,
2015                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
2016         },
2017         {
2018                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
2019                         gettext_noop("Sets the planner's estimate of the cost of "
2020                                                  "processing each operator or function call."),
2021                         NULL
2022                 },
2023                 &cpu_operator_cost,
2024                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
2025         },
2026
2027         {
2028                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2029                         gettext_noop("Sets the planner's estimate of the fraction of "
2030                                                  "a cursor's rows that will be retrieved."),
2031                         NULL
2032                 },
2033                 &cursor_tuple_fraction,
2034                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
2035         },
2036
2037         {
2038                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2039                         gettext_noop("GEQO: selective pressure within the population."),
2040                         NULL
2041                 },
2042                 &Geqo_selection_bias,
2043                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
2044                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
2045         },
2046         {
2047                 {"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
2048                         gettext_noop("GEQO: seed for random path selection."),
2049                         NULL
2050                 },
2051                 &Geqo_seed,
2052                 0.0, 0.0, 1.0, NULL, NULL
2053         },
2054
2055         {
2056                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2057                         gettext_noop("Multiple of the average buffer usage to free per round."),
2058                         NULL
2059                 },
2060                 &bgwriter_lru_multiplier,
2061                 2.0, 0.0, 10.0, NULL, NULL
2062         },
2063
2064         {
2065                 {"seed", PGC_USERSET, UNGROUPED,
2066                         gettext_noop("Sets the seed for random-number generation."),
2067                         NULL,
2068                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2069                 },
2070                 &phony_random_seed,
2071                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2072         },
2073
2074         {
2075                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2076                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2077                         NULL
2078                 },
2079                 &autovacuum_vac_scale,
2080                 0.2, 0.0, 100.0, NULL, NULL
2081         },
2082         {
2083                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2084                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2085                         NULL
2086                 },
2087                 &autovacuum_anl_scale,
2088                 0.1, 0.0, 100.0, NULL, NULL
2089         },
2090
2091         {
2092                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2093                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2094                         NULL
2095                 },
2096                 &CheckPointCompletionTarget,
2097                 0.5, 0.0, 1.0, NULL, NULL
2098         },
2099
2100         /* End-of-list marker */
2101         {
2102                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2103         }
2104 };
2105
2106
2107 static struct config_string ConfigureNamesString[] =
2108 {
2109         {
2110                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2111                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2112                         NULL
2113                 },
2114                 &XLogArchiveCommand,
2115                 "", NULL, show_archive_command
2116         },
2117
2118         {
2119                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2120                         gettext_noop("Sets the client's character set encoding."),
2121                         NULL,
2122                         GUC_IS_NAME | GUC_REPORT
2123                 },
2124                 &client_encoding_string,
2125                 "SQL_ASCII", assign_client_encoding, NULL
2126         },
2127
2128         {
2129                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2130                         gettext_noop("Controls information prefixed to each log line."),
2131                         gettext_noop("If blank, no prefix is used.")
2132                 },
2133                 &Log_line_prefix,
2134                 "", NULL, NULL
2135         },
2136
2137         {
2138                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2139                         gettext_noop("Sets the time zone to use in log messages."),
2140                         NULL
2141                 },
2142                 &log_timezone_string,
2143                 "UNKNOWN", assign_log_timezone, show_log_timezone
2144         },
2145
2146         {
2147                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2148                         gettext_noop("Sets the display format for date and time values."),
2149                         gettext_noop("Also controls interpretation of ambiguous "
2150                                                  "date inputs."),
2151                         GUC_LIST_INPUT | GUC_REPORT
2152                 },
2153                 &datestyle_string,
2154                 "ISO, MDY", assign_datestyle, NULL
2155         },
2156
2157         {
2158                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2159                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2160                         gettext_noop("An empty string selects the database's default tablespace."),
2161                         GUC_IS_NAME
2162                 },
2163                 &default_tablespace,
2164                 "", assign_default_tablespace, NULL
2165         },
2166
2167         {
2168                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2169                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2170                         NULL,
2171                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2172                 },
2173                 &temp_tablespaces,
2174                 "", assign_temp_tablespaces, NULL
2175         },
2176
2177         {
2178                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2179                         gettext_noop("Sets the path for dynamically loadable modules."),
2180                         gettext_noop("If a dynamically loadable module needs to be opened and "
2181                                                  "the specified name does not have a directory component (i.e., the "
2182                                                  "name does not contain a slash), the system will search this path for "
2183                                                  "the specified file."),
2184                         GUC_SUPERUSER_ONLY
2185                 },
2186                 &Dynamic_library_path,
2187                 "$libdir", NULL, NULL
2188         },
2189
2190         {
2191                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2192                         gettext_noop("Sets the location of the Kerberos server key file."),
2193                         NULL,
2194                         GUC_SUPERUSER_ONLY
2195                 },
2196                 &pg_krb_server_keyfile,
2197                 PG_KRB_SRVTAB, NULL, NULL
2198         },
2199
2200         {
2201                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2202                         gettext_noop("Sets the name of the Kerberos service."),
2203                         NULL
2204                 },
2205                 &pg_krb_srvnam,
2206                 PG_KRB_SRVNAM, NULL, NULL
2207         },
2208
2209         {
2210                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2211                         gettext_noop("Sets the Bonjour service name."),
2212                         NULL
2213                 },
2214                 &bonjour_name,
2215                 "", NULL, NULL
2216         },
2217
2218         /* See main.c about why defaults for LC_foo are not all alike */
2219
2220         {
2221                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2222                         gettext_noop("Shows the collation order locale."),
2223                         NULL,
2224                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2225                 },
2226                 &locale_collate,
2227                 "C", NULL, NULL
2228         },
2229
2230         {
2231                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2232                         gettext_noop("Shows the character classification and case conversion locale."),
2233                         NULL,
2234                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2235                 },
2236                 &locale_ctype,
2237                 "C", NULL, NULL
2238         },
2239
2240         {
2241                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2242                         gettext_noop("Sets the language in which messages are displayed."),
2243                         NULL
2244                 },
2245                 &locale_messages,
2246                 "", locale_messages_assign, NULL
2247         },
2248
2249         {
2250                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2251                         gettext_noop("Sets the locale for formatting monetary amounts."),
2252                         NULL
2253                 },
2254                 &locale_monetary,
2255                 "C", locale_monetary_assign, NULL
2256         },
2257
2258         {
2259                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2260                         gettext_noop("Sets the locale for formatting numbers."),
2261                         NULL
2262                 },
2263                 &locale_numeric,
2264                 "C", locale_numeric_assign, NULL
2265         },
2266
2267         {
2268                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2269                         gettext_noop("Sets the locale for formatting date and time values."),
2270                         NULL
2271                 },
2272                 &locale_time,
2273                 "C", locale_time_assign, NULL
2274         },
2275
2276         {
2277                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2278                         gettext_noop("Lists shared libraries to preload into server."),
2279                         NULL,
2280                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2281                 },
2282                 &shared_preload_libraries_string,
2283                 "", NULL, NULL
2284         },
2285
2286         {
2287                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2288                         gettext_noop("Lists shared libraries to preload into each backend."),
2289                         NULL,
2290                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2291                 },
2292                 &local_preload_libraries_string,
2293                 "", NULL, NULL
2294         },
2295
2296         {
2297                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2298                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2299                         NULL,
2300                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2301                 },
2302                 &namespace_search_path,
2303                 "\"$user\",public", assign_search_path, NULL
2304         },
2305
2306         {
2307                 /* Can't be set in postgresql.conf */
2308                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2309                         gettext_noop("Sets the server (database) character set encoding."),
2310                         NULL,
2311                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2312                 },
2313                 &server_encoding_string,
2314                 "SQL_ASCII", NULL, NULL
2315         },
2316
2317         {
2318                 /* Can't be set in postgresql.conf */
2319                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2320                         gettext_noop("Shows the server version."),
2321                         NULL,
2322                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2323                 },
2324                 &server_version_string,
2325                 PG_VERSION, NULL, NULL
2326         },
2327
2328         {
2329                 /* Not for general use --- used by SET ROLE */
2330                 {"role", PGC_USERSET, UNGROUPED,
2331                         gettext_noop("Sets the current role."),
2332                         NULL,
2333                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE | GUC_NOT_WHILE_SEC_DEF
2334                 },
2335                 &role_string,
2336                 "none", assign_role, show_role
2337         },
2338
2339         {
2340                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2341                 {"session_authorization", PGC_USERSET, UNGROUPED,
2342                         gettext_noop("Sets the session user name."),
2343                         NULL,
2344                         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_DEF
2345                 },
2346                 &session_authorization_string,
2347                 NULL, assign_session_authorization, show_session_authorization
2348         },
2349
2350         {
2351                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2352                         gettext_noop("Sets the destination for server log output."),
2353                         gettext_noop("Valid values are combinations of \"stderr\", "
2354                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2355                                                  "depending on the platform."),
2356                         GUC_LIST_INPUT
2357                 },
2358                 &log_destination_string,
2359                 "stderr", assign_log_destination, NULL
2360         },
2361         {
2362                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2363                         gettext_noop("Sets the destination directory for log files."),
2364                         gettext_noop("Can be specified as relative to the data directory "
2365                                                  "or as absolute path."),
2366                         GUC_SUPERUSER_ONLY
2367                 },
2368                 &Log_directory,
2369                 "pg_log", assign_canonical_path, NULL
2370         },
2371         {
2372                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2373                         gettext_noop("Sets the file name pattern for log files."),
2374                         NULL,
2375                         GUC_SUPERUSER_ONLY
2376                 },
2377                 &Log_filename,
2378                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2379         },
2380
2381 #ifdef HAVE_SYSLOG
2382         {
2383                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2384                         gettext_noop("Sets the program name used to identify PostgreSQL "
2385                                                  "messages in syslog."),
2386                         NULL
2387                 },
2388                 &syslog_ident_str,
2389                 "postgres", assign_syslog_ident, NULL
2390         },
2391 #endif
2392
2393         {
2394                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2395                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2396                         NULL,
2397                         GUC_REPORT
2398                 },
2399                 &timezone_string,
2400                 "UNKNOWN", assign_timezone, show_timezone
2401         },
2402         {
2403                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2404                         gettext_noop("Selects a file of time zone abbreviations."),
2405                         NULL
2406                 },
2407                 &timezone_abbreviations_string,
2408                 "UNKNOWN", assign_timezone_abbreviations, NULL
2409         },
2410
2411         {
2412                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2413                         gettext_noop("Sets the current transaction's isolation level."),
2414                         NULL,
2415                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2416                 },
2417                 &XactIsoLevel_string,
2418                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2419         },
2420
2421         {
2422                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2423                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2424                         gettext_noop("The owning user of the socket is always the user "
2425                                                  "that starts the server.")
2426                 },
2427                 &Unix_socket_group,
2428                 "", NULL, NULL
2429         },
2430
2431         {
2432                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2433                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2434                         NULL,
2435                         GUC_SUPERUSER_ONLY
2436                 },
2437                 &UnixSocketDir,
2438                 "", assign_canonical_path, NULL
2439         },
2440
2441         {
2442                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2443                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2444                         NULL,
2445                         GUC_LIST_INPUT
2446                 },
2447                 &ListenAddresses,
2448                 "localhost", NULL, NULL
2449         },
2450
2451         {
2452                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2453                         gettext_noop("Sets the list of known custom variable classes."),
2454                         NULL,
2455                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2456                 },
2457                 &custom_variable_classes,
2458                 NULL, assign_custom_variable_classes, NULL
2459         },
2460
2461         {
2462                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2463                         gettext_noop("Sets the server's data directory."),
2464                         NULL,
2465                         GUC_SUPERUSER_ONLY
2466                 },
2467                 &data_directory,
2468                 NULL, NULL, NULL
2469         },
2470
2471         {
2472                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2473                         gettext_noop("Sets the server's main configuration file."),
2474                         NULL,
2475                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2476                 },
2477                 &ConfigFileName,
2478                 NULL, NULL, NULL
2479         },
2480
2481         {
2482                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2483                         gettext_noop("Sets the server's \"hba\" configuration file."),
2484                         NULL,
2485                         GUC_SUPERUSER_ONLY
2486                 },
2487                 &HbaFileName,
2488                 NULL, NULL, NULL
2489         },
2490
2491         {
2492                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2493                         gettext_noop("Sets the server's \"ident\" configuration file."),
2494                         NULL,
2495                         GUC_SUPERUSER_ONLY
2496                 },
2497                 &IdentFileName,
2498                 NULL, NULL, NULL
2499         },
2500
2501         {
2502                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2503                         gettext_noop("Writes the postmaster PID to the specified file."),
2504                         NULL,
2505                         GUC_SUPERUSER_ONLY
2506                 },
2507                 &external_pid_file,
2508                 NULL, assign_canonical_path, NULL
2509         },
2510
2511         {
2512                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2513                         gettext_noop("Writes temporary statistics files to the specified directory."),
2514                         NULL,
2515                         GUC_SUPERUSER_ONLY
2516                 },
2517                 &pgstat_temp_directory,
2518                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2519         },
2520
2521         {
2522                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2523                         gettext_noop("Sets default text search configuration."),
2524                         NULL
2525                 },
2526                 &TSCurrentConfig,
2527                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2528         },
2529
2530 #ifdef USE_SSL
2531         {
2532                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2533                         gettext_noop("Sets the list of allowed SSL ciphers."),
2534                         NULL,
2535                         GUC_SUPERUSER_ONLY
2536                 },
2537                 &SSLCipherSuites,
2538                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2539         },
2540 #endif   /* USE_SSL */
2541
2542         /* End-of-list marker */
2543         {
2544                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2545         }
2546 };
2547
2548
2549 static struct config_enum ConfigureNamesEnum[] =
2550 {
2551         {
2552                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2553                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2554                         NULL
2555                 },
2556                 &backslash_quote,
2557                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2558         },
2559
2560         {
2561                 {"bytea_output", PGC_USERSET, CLIENT_CONN_STATEMENT,
2562                         gettext_noop("Sets the output format for bytea."),
2563                         NULL
2564                 },
2565                 &bytea_output,
2566                 BYTEA_OUTPUT_HEX, bytea_output_options, NULL, NULL
2567         },
2568
2569         {
2570                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2571                         gettext_noop("Sets the message levels that are sent to the client."),
2572                         gettext_noop("Each level includes all the levels that follow it. The later"
2573                                                  " the level, the fewer messages are sent.")
2574                 },
2575                 &client_min_messages,
2576                 NOTICE, client_message_level_options, NULL, NULL
2577         },
2578
2579         {
2580                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2581                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2582                         gettext_noop("Table scans will be skipped if their constraints"
2583                                                  " guarantee that no rows match the query.")
2584                 },
2585                 &constraint_exclusion,
2586                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2587                 NULL, NULL
2588         },
2589
2590         {
2591                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2592                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2593                         NULL
2594                 },
2595                 &DefaultXactIsoLevel,
2596                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2597         },
2598
2599         {
2600                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2601                         gettext_noop("Sets the display format for interval values."),
2602                         NULL,
2603                         GUC_REPORT
2604                 },
2605                 &IntervalStyle,
2606                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2607         },
2608
2609         {
2610                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2611                         gettext_noop("Sets the verbosity of logged messages."),
2612                         NULL
2613                 },
2614                 &Log_error_verbosity,
2615                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2616         },
2617
2618         {
2619                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2620                         gettext_noop("Sets the message levels that are logged."),
2621                         gettext_noop("Each level includes all the levels that follow it. The later"
2622                                                  " the level, the fewer messages are sent.")
2623                 },
2624                 &log_min_messages,
2625                 WARNING, server_message_level_options, NULL, NULL
2626         },
2627
2628         {
2629                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2630                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2631                         gettext_noop("Each level includes all the levels that follow it. The later"
2632                                                  " the level, the fewer messages are sent.")
2633                 },
2634                 &log_min_error_statement,
2635                 ERROR, server_message_level_options, NULL, NULL
2636         },
2637
2638         {
2639                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2640                         gettext_noop("Sets the type of statements logged."),
2641                         NULL
2642                 },
2643                 &log_statement,
2644                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2645         },
2646
2647 #ifdef HAVE_SYSLOG
2648         {
2649                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2650                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2651                         NULL
2652                 },
2653                 &syslog_facility,
2654                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2655         },
2656 #endif
2657
2658         {
2659                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2660                         gettext_noop("Sets the regular expression \"flavor\"."),
2661                         NULL
2662                 },
2663                 &regex_flavor,
2664                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2665         },
2666
2667         {
2668                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2669                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2670                         NULL
2671                 },
2672                 &SessionReplicationRole,
2673                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2674                 assign_session_replication_role, NULL
2675         },
2676
2677         {
2678                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2679                         gettext_noop("Collects function-level statistics on database activity."),
2680                         NULL
2681                 },
2682                 &pgstat_track_functions,
2683                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2684         },
2685
2686         {
2687                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2688                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2689                         NULL
2690                 },
2691                 &sync_method,
2692                 DEFAULT_SYNC_METHOD, sync_method_options,
2693                 assign_xlog_sync_method, NULL
2694         },
2695
2696         {
2697                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2698                         gettext_noop("Sets how binary values are to be encoded in XML."),
2699                         NULL
2700                 },
2701                 &xmlbinary,
2702                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2703         },
2704
2705         {
2706                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2707                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2708                                                  "operations is to be considered as documents or content fragments."),
2709                         NULL
2710                 },
2711                 &xmloption,
2712                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2713         },
2714
2715
2716         /* End-of-list marker */
2717         {
2718                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2719         }
2720 };
2721
2722 /******** end of options list ********/
2723
2724
2725 /*
2726  * To allow continued support of obsolete names for GUC variables, we apply
2727  * the following mappings to any unrecognized name.  Note that an old name
2728  * should be mapped to a new one only if the new variable has very similar
2729  * semantics to the old.
2730  */
2731 static const char *const map_old_guc_names[] = {
2732         "sort_mem", "work_mem",
2733         "vacuum_mem", "maintenance_work_mem",
2734         NULL
2735 };
2736
2737
2738 /*
2739  * Actual lookup of variables is done through this single, sorted array.
2740  */
2741 static struct config_generic **guc_variables;
2742
2743 /* Current number of variables contained in the vector */
2744 static int      num_guc_variables;
2745
2746 /* Vector capacity */
2747 static int      size_guc_variables;
2748
2749
2750 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2751
2752 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2753
2754 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2755
2756
2757 static int      guc_var_compare(const void *a, const void *b);
2758 static int      guc_name_compare(const char *namea, const char *nameb);
2759 static void InitializeOneGUCOption(struct config_generic * gconf);
2760 static void push_old_value(struct config_generic * gconf, GucAction action);
2761 static void ReportGUCOption(struct config_generic * record);
2762 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2763 static void ShowAllGUCConfig(DestReceiver *dest);
2764 static char *_ShowOption(struct config_generic * record, bool use_units);
2765 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2766
2767
2768 /*
2769  * Some infrastructure for checking malloc/strdup/realloc calls
2770  */
2771 static void *
2772 guc_malloc(int elevel, size_t size)
2773 {
2774         void       *data;
2775
2776         data = malloc(size);
2777         if (data == NULL)
2778                 ereport(elevel,
2779                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2780                                  errmsg("out of memory")));
2781         return data;
2782 }
2783
2784 static void *
2785 guc_realloc(int elevel, void *old, size_t size)
2786 {
2787         void       *data;
2788
2789         data = realloc(old, size);
2790         if (data == NULL)
2791                 ereport(elevel,
2792                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2793                                  errmsg("out of memory")));
2794         return data;
2795 }
2796
2797 static char *
2798 guc_strdup(int elevel, const char *src)
2799 {
2800         char       *data;
2801
2802         data = strdup(src);
2803         if (data == NULL)
2804                 ereport(elevel,
2805                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2806                                  errmsg("out of memory")));
2807         return data;
2808 }
2809
2810
2811 /*
2812  * Support for assigning to a field of a string GUC item.  Free the prior
2813  * value if it's not referenced anywhere else in the item (including stacked
2814  * states).
2815  */
2816 static void
2817 set_string_field(struct config_string * conf, char **field, char *newval)
2818 {
2819         char       *oldval = *field;
2820         GucStack   *stack;
2821
2822         /* Do the assignment */
2823         *field = newval;
2824
2825         /* Exit if any duplicate references, or if old value was NULL anyway */
2826         if (oldval == NULL ||
2827                 oldval == *(conf->variable) ||
2828                 oldval == conf->reset_val ||
2829                 oldval == conf->boot_val)
2830                 return;
2831         for (stack = conf->gen.stack; stack; stack = stack->prev)
2832         {
2833                 if (oldval == stack->prior.stringval ||
2834                         oldval == stack->masked.stringval)
2835                         return;
2836         }
2837
2838         /* Not used anymore, so free it */
2839         free(oldval);
2840 }
2841
2842 /*
2843  * Detect whether strval is referenced anywhere in a GUC string item
2844  */
2845 static bool
2846 string_field_used(struct config_string * conf, char *strval)
2847 {
2848         GucStack   *stack;
2849
2850         if (strval == *(conf->variable) ||
2851                 strval == conf->reset_val ||
2852                 strval == conf->boot_val)
2853                 return true;
2854         for (stack = conf->gen.stack; stack; stack = stack->prev)
2855         {
2856                 if (strval == stack->prior.stringval ||
2857                         strval == stack->masked.stringval)
2858                         return true;
2859         }
2860         return false;
2861 }
2862
2863 /*
2864  * Support for copying a variable's active value into a stack entry
2865  */
2866 static void
2867 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2868 {
2869         switch (gconf->vartype)
2870         {
2871                 case PGC_BOOL:
2872                         val->boolval =
2873                                 *((struct config_bool *) gconf)->variable;
2874                         break;
2875                 case PGC_INT:
2876                         val->intval =
2877                                 *((struct config_int *) gconf)->variable;
2878                         break;
2879                 case PGC_REAL:
2880                         val->realval =
2881                                 *((struct config_real *) gconf)->variable;
2882                         break;
2883                 case PGC_STRING:
2884                         /* we assume stringval is NULL if not valid */
2885                         set_string_field((struct config_string *) gconf,
2886                                                          &(val->stringval),
2887                                                          *((struct config_string *) gconf)->variable);
2888                         break;
2889                 case PGC_ENUM:
2890                         val->enumval =
2891                                 *((struct config_enum *) gconf)->variable;
2892                         break;
2893         }
2894 }
2895
2896 /*
2897  * Support for discarding a no-longer-needed value in a stack entry
2898  */
2899 static void
2900 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2901 {
2902         switch (gconf->vartype)
2903         {
2904                 case PGC_BOOL:
2905                 case PGC_INT:
2906                 case PGC_REAL:
2907                 case PGC_ENUM:
2908                         /* no need to do anything */
2909                         break;
2910                 case PGC_STRING:
2911                         set_string_field((struct config_string *) gconf,
2912                                                          &(val->stringval),
2913                                                          NULL);
2914                         break;
2915         }
2916 }
2917
2918
2919 /*
2920  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2921  */
2922 struct config_generic **
2923 get_guc_variables(void)
2924 {
2925         return guc_variables;
2926 }
2927
2928
2929 /*
2930  * Build the sorted array.      This is split out so that it could be
2931  * re-executed after startup (eg, we could allow loadable modules to
2932  * add vars, and then we'd need to re-sort).
2933  */
2934 void
2935 build_guc_variables(void)
2936 {
2937         int                     size_vars;
2938         int                     num_vars = 0;
2939         struct config_generic **guc_vars;
2940         int                     i;
2941
2942         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2943         {
2944                 struct config_bool *conf = &ConfigureNamesBool[i];
2945
2946                 /* Rather than requiring vartype to be filled in by hand, do this: */
2947                 conf->gen.vartype = PGC_BOOL;
2948                 num_vars++;
2949         }
2950
2951         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2952         {
2953                 struct config_int *conf = &ConfigureNamesInt[i];
2954
2955                 conf->gen.vartype = PGC_INT;
2956                 num_vars++;
2957         }
2958
2959         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2960         {
2961                 struct config_real *conf = &ConfigureNamesReal[i];
2962
2963                 conf->gen.vartype = PGC_REAL;
2964                 num_vars++;
2965         }
2966
2967         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2968         {
2969                 struct config_string *conf = &ConfigureNamesString[i];
2970
2971                 conf->gen.vartype = PGC_STRING;
2972                 num_vars++;
2973         }
2974
2975         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2976         {
2977                 struct config_enum *conf = &ConfigureNamesEnum[i];
2978
2979                 conf->gen.vartype = PGC_ENUM;
2980                 num_vars++;
2981         }
2982
2983         /*
2984          * Create table with 20% slack
2985          */
2986         size_vars = num_vars + num_vars / 4;
2987
2988         guc_vars = (struct config_generic **)
2989                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2990
2991         num_vars = 0;
2992
2993         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2994                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2995
2996         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2997                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2998
2999         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
3000                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
3001
3002         for (i = 0; ConfigureNamesString[i].gen.name; i++)
3003                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
3004
3005         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
3006                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
3007
3008         if (guc_variables)
3009                 free(guc_variables);
3010         guc_variables = guc_vars;
3011         num_guc_variables = num_vars;
3012         size_guc_variables = size_vars;
3013         qsort((void *) guc_variables, num_guc_variables,
3014                   sizeof(struct config_generic *), guc_var_compare);
3015 }
3016
3017 /*
3018  * Add a new GUC variable to the list of known variables. The
3019  * list is expanded if needed.
3020  */
3021 static bool
3022 add_guc_variable(struct config_generic * var, int elevel)
3023 {
3024         if (num_guc_variables + 1 >= size_guc_variables)
3025         {
3026                 /*
3027                  * Increase the vector by 25%
3028                  */
3029                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
3030                 struct config_generic **guc_vars;
3031
3032                 if (size_vars == 0)
3033                 {
3034                         size_vars = 100;
3035                         guc_vars = (struct config_generic **)
3036                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3037                 }
3038                 else
3039                 {
3040                         guc_vars = (struct config_generic **)
3041                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3042                 }
3043
3044                 if (guc_vars == NULL)
3045                         return false;           /* out of memory */
3046
3047                 guc_variables = guc_vars;
3048                 size_guc_variables = size_vars;
3049         }
3050         guc_variables[num_guc_variables++] = var;
3051         qsort((void *) guc_variables, num_guc_variables,
3052                   sizeof(struct config_generic *), guc_var_compare);
3053         return true;
3054 }
3055
3056 /*
3057  * Create and add a placeholder variable. It's presumed to belong
3058  * to a valid custom variable class at this point.
3059  */
3060 static struct config_generic *
3061 add_placeholder_variable(const char *name, int elevel)
3062 {
3063         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3064         struct config_string *var;
3065         struct config_generic *gen;
3066
3067         var = (struct config_string *) guc_malloc(elevel, sz);
3068         if (var == NULL)
3069                 return NULL;
3070         memset(var, 0, sz);
3071         gen = &var->gen;
3072
3073         gen->name = guc_strdup(elevel, name);
3074         if (gen->name == NULL)
3075         {
3076                 free(var);
3077                 return NULL;
3078         }
3079
3080         gen->context = PGC_USERSET;
3081         gen->group = CUSTOM_OPTIONS;
3082         gen->short_desc = "GUC placeholder variable";
3083         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3084         gen->vartype = PGC_STRING;
3085
3086         /*
3087          * The char* is allocated at the end of the struct since we have no
3088          * 'static' place to point to.  Note that the current value, as well as
3089          * the boot and reset values, start out NULL.
3090          */
3091         var->variable = (char **) (var + 1);
3092
3093         if (!add_guc_variable((struct config_generic *) var, elevel))
3094         {
3095                 free((void *) gen->name);
3096                 free(var);
3097                 return NULL;
3098         }
3099
3100         return gen;
3101 }
3102
3103 /*
3104  * Detect whether the portion of "name" before dotPos matches any custom
3105  * variable class name listed in custom_var_classes.  The latter must be
3106  * formatted the way that assign_custom_variable_classes does it, ie,
3107  * no whitespace.  NULL is valid for custom_var_classes.
3108  */
3109 static bool
3110 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3111 {
3112         bool            result = false;
3113         const char *ccs = custom_var_classes;
3114
3115         if (ccs != NULL)
3116         {
3117                 const char *start = ccs;
3118
3119                 for (;; ++ccs)
3120                 {
3121                         char            c = *ccs;
3122
3123                         if (c == '\0' || c == ',')
3124                         {
3125                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3126                                 {
3127                                         result = true;
3128                                         break;
3129                                 }
3130                                 if (c == '\0')
3131                                         break;
3132                                 start = ccs + 1;
3133                         }
3134                 }
3135         }
3136         return result;
3137 }
3138
3139 /*
3140  * Look up option NAME.  If it exists, return a pointer to its record,
3141  * else return NULL.  If create_placeholders is TRUE, we'll create a
3142  * placeholder record for a valid-looking custom variable name.
3143  */
3144 static struct config_generic *
3145 find_option(const char *name, bool create_placeholders, int elevel)
3146 {
3147         const char **key = &name;
3148         struct config_generic **res;
3149         int                     i;
3150
3151         Assert(name);
3152
3153         /*
3154          * By equating const char ** with struct config_generic *, we are assuming
3155          * the name field is first in config_generic.
3156          */
3157         res = (struct config_generic **) bsearch((void *) &key,
3158                                                                                          (void *) guc_variables,
3159                                                                                          num_guc_variables,
3160                                                                                          sizeof(struct config_generic *),
3161                                                                                          guc_var_compare);
3162         if (res)
3163                 return *res;
3164
3165         /*
3166          * See if the name is an obsolete name for a variable.  We assume that the
3167          * set of supported old names is short enough that a brute-force search is
3168          * the best way.
3169          */
3170         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3171         {
3172                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3173                         return find_option(map_old_guc_names[i + 1], false, elevel);
3174         }
3175
3176         if (create_placeholders)
3177         {
3178                 /*
3179                  * Check if the name is qualified, and if so, check if the qualifier
3180                  * matches any custom variable class.  If so, add a placeholder.
3181                  */
3182                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3183
3184                 if (dot != NULL &&
3185                         is_custom_class(name, dot - name, custom_variable_classes))
3186                         return add_placeholder_variable(name, elevel);
3187         }
3188
3189         /* Unknown name */
3190         return NULL;
3191 }
3192
3193
3194 /*
3195  * comparator for qsorting and bsearching guc_variables array
3196  */
3197 static int
3198 guc_var_compare(const void *a, const void *b)
3199 {
3200         struct config_generic *confa = *(struct config_generic **) a;
3201         struct config_generic *confb = *(struct config_generic **) b;
3202
3203         return guc_name_compare(confa->name, confb->name);
3204 }
3205
3206 /*
3207  * the bare comparison function for GUC names
3208  */
3209 static int
3210 guc_name_compare(const char *namea, const char *nameb)
3211 {
3212         /*
3213          * The temptation to use strcasecmp() here must be resisted, because the
3214          * array ordering has to remain stable across setlocale() calls. So, build
3215          * our own with a simple ASCII-only downcasing.
3216          */
3217         while (*namea && *nameb)
3218         {
3219                 char            cha = *namea++;
3220                 char            chb = *nameb++;
3221
3222                 if (cha >= 'A' && cha <= 'Z')
3223                         cha += 'a' - 'A';
3224                 if (chb >= 'A' && chb <= 'Z')
3225                         chb += 'a' - 'A';
3226                 if (cha != chb)
3227                         return cha - chb;
3228         }
3229         if (*namea)
3230                 return 1;                               /* a is longer */
3231         if (*nameb)
3232                 return -1;                              /* b is longer */
3233         return 0;
3234 }
3235
3236
3237 /*
3238  * Initialize GUC options during program startup.
3239  *
3240  * Note that we cannot read the config file yet, since we have not yet
3241  * processed command-line switches.
3242  */
3243 void
3244 InitializeGUCOptions(void)
3245 {
3246         int                     i;
3247         char       *env;
3248         long            stack_rlimit;
3249
3250         /*
3251          * Before log_line_prefix could possibly receive a nonempty setting, make
3252          * sure that timezone processing is minimally alive (see elog.c).
3253          */
3254         pg_timezone_pre_initialize();
3255
3256         /*
3257          * Build sorted array of all GUC variables.
3258          */
3259         build_guc_variables();
3260
3261         /*
3262          * Load all variables with their compiled-in defaults, and initialize
3263          * status fields as needed.
3264          */
3265         for (i = 0; i < num_guc_variables; i++)
3266         {
3267                 InitializeOneGUCOption(guc_variables[i]);
3268         }
3269
3270         guc_dirty = false;
3271
3272         reporting_enabled = false;
3273
3274         /*
3275          * Prevent any attempt to override the transaction modes from
3276          * non-interactive sources.
3277          */
3278         SetConfigOption("transaction_isolation", "default",
3279                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3280         SetConfigOption("transaction_read_only", "no",
3281                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3282
3283         /*
3284          * For historical reasons, some GUC parameters can receive defaults from
3285          * environment variables.  Process those settings.      NB: if you add or
3286          * remove anything here, see also ProcessConfigFile().
3287          */
3288
3289         env = getenv("PGPORT");
3290         if (env != NULL)
3291                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3292
3293         env = getenv("PGDATESTYLE");
3294         if (env != NULL)
3295                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3296
3297         env = getenv("PGCLIENTENCODING");
3298         if (env != NULL)
3299                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3300
3301         /*
3302          * rlimit isn't exactly an "environment variable", but it behaves about
3303          * the same.  If we can identify the platform stack depth rlimit, increase
3304          * default stack depth setting up to whatever is safe (but at most 2MB).
3305          */
3306         stack_rlimit = get_stack_depth_rlimit();
3307         if (stack_rlimit > 0)
3308         {
3309                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3310
3311                 if (new_limit > 100)
3312                 {
3313                         char            limbuf[16];
3314
3315                         new_limit = Min(new_limit, 2048);
3316                         sprintf(limbuf, "%d", new_limit);
3317                         SetConfigOption("max_stack_depth", limbuf,
3318                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3319                 }
3320         }
3321 }
3322
3323 /*
3324  * Initialize one GUC option variable to its compiled-in default.
3325  */
3326 static void
3327 InitializeOneGUCOption(struct config_generic * gconf)
3328 {
3329         gconf->status = 0;
3330         gconf->reset_source = PGC_S_DEFAULT;
3331         gconf->source = PGC_S_DEFAULT;
3332         gconf->stack = NULL;
3333         gconf->sourcefile = NULL;
3334         gconf->sourceline = 0;
3335
3336         switch (gconf->vartype)
3337         {
3338                 case PGC_BOOL:
3339                         {
3340                                 struct config_bool *conf = (struct config_bool *) gconf;
3341
3342                                 if (conf->assign_hook)
3343                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3344                                                                                            PGC_S_DEFAULT))
3345                                                 elog(FATAL, "failed to initialize %s to %d",
3346                                                          conf->gen.name, (int) conf->boot_val);
3347                                 *conf->variable = conf->reset_val = conf->boot_val;
3348                                 break;
3349                         }
3350                 case PGC_INT:
3351                         {
3352                                 struct config_int *conf = (struct config_int *) gconf;
3353
3354                                 Assert(conf->boot_val >= conf->min);
3355                                 Assert(conf->boot_val <= conf->max);
3356                                 if (conf->assign_hook)
3357                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3358                                                                                            PGC_S_DEFAULT))
3359                                                 elog(FATAL, "failed to initialize %s to %d",
3360                                                          conf->gen.name, conf->boot_val);
3361                                 *conf->variable = conf->reset_val = conf->boot_val;
3362                                 break;
3363                         }
3364                 case PGC_REAL:
3365                         {
3366                                 struct config_real *conf = (struct config_real *) gconf;
3367
3368                                 Assert(conf->boot_val >= conf->min);
3369                                 Assert(conf->boot_val <= conf->max);
3370                                 if (conf->assign_hook)
3371                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3372                                                                                            PGC_S_DEFAULT))
3373                                                 elog(FATAL, "failed to initialize %s to %g",
3374                                                          conf->gen.name, conf->boot_val);
3375                                 *conf->variable = conf->reset_val = conf->boot_val;
3376                                 break;
3377                         }
3378                 case PGC_STRING:
3379                         {
3380                                 struct config_string *conf = (struct config_string *) gconf;
3381                                 char       *str;
3382
3383                                 *conf->variable = NULL;
3384                                 conf->reset_val = NULL;
3385
3386                                 if (conf->boot_val == NULL)
3387                                 {
3388                                         /* leave the value NULL, do not call assign hook */
3389                                         break;
3390                                 }
3391
3392                                 str = guc_strdup(FATAL, conf->boot_val);
3393                                 conf->reset_val = str;
3394
3395                                 if (conf->assign_hook)
3396                                 {
3397                                         const char *newstr;
3398
3399                                         newstr = (*conf->assign_hook) (str, true,
3400                                                                                                    PGC_S_DEFAULT);
3401                                         if (newstr == NULL)
3402                                         {
3403                                                 elog(FATAL, "failed to initialize %s to \"%s\"",
3404                                                          conf->gen.name, str);
3405                                         }
3406                                         else if (newstr != str)
3407                                         {
3408                                                 free(str);
3409
3410                                                 /*
3411                                                  * See notes in set_config_option about casting
3412                                                  */
3413                                                 str = (char *) newstr;
3414                                                 conf->reset_val = str;
3415                                         }
3416                                 }
3417                                 *conf->variable = str;
3418                                 break;
3419                         }
3420                 case PGC_ENUM:
3421                         {
3422                                 struct config_enum *conf = (struct config_enum *) gconf;
3423
3424                                 if (conf->assign_hook)
3425                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3426                                                                                            PGC_S_DEFAULT))
3427                                                 elog(FATAL, "failed to initialize %s to %s",
3428                                                          conf->gen.name,
3429                                                   config_enum_lookup_by_value(conf, conf->boot_val));
3430                                 *conf->variable = conf->reset_val = conf->boot_val;
3431                                 break;
3432                         }
3433         }
3434 }
3435
3436
3437 /*
3438  * Select the configuration files and data directory to be used, and
3439  * do the initial read of postgresql.conf.
3440  *
3441  * This is called after processing command-line switches.
3442  *              userDoption is the -D switch value if any (NULL if unspecified).
3443  *              progname is just for use in error messages.
3444  *
3445  * Returns true on success; on failure, prints a suitable error message
3446  * to stderr and returns false.
3447  */
3448 bool
3449 SelectConfigFiles(const char *userDoption, const char *progname)
3450 {
3451         char       *configdir;
3452         char       *fname;
3453         struct stat stat_buf;
3454
3455         /* configdir is -D option, or $PGDATA if no -D */
3456         if (userDoption)
3457                 configdir = make_absolute_path(userDoption);
3458         else
3459                 configdir = make_absolute_path(getenv("PGDATA"));
3460
3461         /*
3462          * Find the configuration file: if config_file was specified on the
3463          * command line, use it, else use configdir/postgresql.conf.  In any case
3464          * ensure the result is an absolute path, so that it will be interpreted
3465          * the same way by future backends.
3466          */
3467         if (ConfigFileName)
3468                 fname = make_absolute_path(ConfigFileName);
3469         else if (configdir)
3470         {
3471                 fname = guc_malloc(FATAL,
3472                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3473                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3474         }
3475         else
3476         {
3477                 write_stderr("%s does not know where to find the server configuration file.\n"
3478                                          "You must specify the --config-file or -D invocation "
3479                                          "option or set the PGDATA environment variable.\n",
3480                                          progname);
3481                 return false;
3482         }
3483
3484         /*
3485          * Set the ConfigFileName GUC variable to its final value, ensuring that
3486          * it can't be overridden later.
3487          */
3488         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3489         free(fname);
3490
3491         /*
3492          * Now read the config file for the first time.
3493          */
3494         if (stat(ConfigFileName, &stat_buf) != 0)
3495         {
3496                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3497                                          progname, ConfigFileName, strerror(errno));
3498                 return false;
3499         }
3500
3501         ProcessConfigFile(PGC_POSTMASTER);
3502
3503         /*
3504          * If the data_directory GUC variable has been set, use that as DataDir;
3505          * otherwise use configdir if set; else punt.
3506          *
3507          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3508          * have to.
3509          */
3510         if (data_directory)
3511                 SetDataDir(data_directory);
3512         else if (configdir)
3513                 SetDataDir(configdir);
3514         else
3515         {
3516                 write_stderr("%s does not know where to find the database system data.\n"
3517                                          "This can be specified as \"data_directory\" in \"%s\", "
3518                                          "or by the -D invocation option, or by the "
3519                                          "PGDATA environment variable.\n",
3520                                          progname, ConfigFileName);
3521                 return false;
3522         }
3523
3524         /*
3525          * Reflect the final DataDir value back into the data_directory GUC var.
3526          * (If you are wondering why we don't just make them a single variable,
3527          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3528          * child backends specially.  XXX is that still true?  Given that we now
3529          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3530          * DataDir in advance.)
3531          */
3532         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3533
3534         /*
3535          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3536          */
3537         if (HbaFileName)
3538                 fname = make_absolute_path(HbaFileName);
3539         else if (configdir)
3540         {
3541                 fname = guc_malloc(FATAL,
3542                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3543                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3544         }
3545         else
3546         {
3547                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3548                                          "This can be specified as \"hba_file\" in \"%s\", "
3549                                          "or by the -D invocation option, or by the "
3550                                          "PGDATA environment variable.\n",
3551                                          progname, ConfigFileName);
3552                 return false;
3553         }
3554         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3555         free(fname);
3556
3557         /*
3558          * Likewise for pg_ident.conf.
3559          */
3560         if (IdentFileName)
3561                 fname = make_absolute_path(IdentFileName);
3562         else if (configdir)
3563         {
3564                 fname = guc_malloc(FATAL,
3565                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3566                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3567         }
3568         else
3569         {
3570                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3571                                          "This can be specified as \"ident_file\" in \"%s\", "
3572                                          "or by the -D invocation option, or by the "
3573                                          "PGDATA environment variable.\n",
3574                                          progname, ConfigFileName);
3575                 return false;
3576         }
3577         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3578         free(fname);
3579
3580         free(configdir);
3581
3582         return true;
3583 }
3584
3585
3586 /*
3587  * Reset all options to their saved default values (implements RESET ALL)
3588  */
3589 void
3590 ResetAllOptions(void)
3591 {
3592         int                     i;
3593
3594         for (i = 0; i < num_guc_variables; i++)
3595         {
3596                 struct config_generic *gconf = guc_variables[i];
3597
3598                 /* Don't reset non-SET-able values */
3599                 if (gconf->context != PGC_SUSET &&
3600                         gconf->context != PGC_USERSET)
3601                         continue;
3602                 /* Don't reset if special exclusion from RESET ALL */
3603                 if (gconf->flags & GUC_NO_RESET_ALL)
3604                         continue;
3605                 /* No need to reset if wasn't SET */
3606                 if (gconf->source <= PGC_S_OVERRIDE)
3607                         continue;
3608
3609                 /* Save old value to support transaction abort */
3610                 push_old_value(gconf, GUC_ACTION_SET);
3611
3612                 switch (gconf->vartype)
3613                 {
3614                         case PGC_BOOL:
3615                                 {
3616                                         struct config_bool *conf = (struct config_bool *) gconf;
3617
3618                                         if (conf->assign_hook)
3619                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3620                                                                                                    PGC_S_SESSION))
3621                                                         elog(ERROR, "failed to reset %s to %d",
3622                                                                  conf->gen.name, (int) conf->reset_val);
3623                                         *conf->variable = conf->reset_val;
3624                                         break;
3625                                 }
3626                         case PGC_INT:
3627                                 {
3628                                         struct config_int *conf = (struct config_int *) gconf;
3629
3630                                         if (conf->assign_hook)
3631                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3632                                                                                                    PGC_S_SESSION))
3633                                                         elog(ERROR, "failed to reset %s to %d",
3634                                                                  conf->gen.name, conf->reset_val);
3635                                         *conf->variable = conf->reset_val;
3636                                         break;
3637                                 }
3638                         case PGC_REAL:
3639                                 {
3640                                         struct config_real *conf = (struct config_real *) gconf;
3641
3642                                         if (conf->assign_hook)
3643                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3644                                                                                                    PGC_S_SESSION))
3645                                                         elog(ERROR, "failed to reset %s to %g",
3646                                                                  conf->gen.name, conf->reset_val);
3647                                         *conf->variable = conf->reset_val;
3648                                         break;
3649                                 }
3650                         case PGC_STRING:
3651                                 {
3652                                         struct config_string *conf = (struct config_string *) gconf;
3653                                         char       *str;
3654
3655                                         /* We need not strdup here */
3656                                         str = conf->reset_val;
3657
3658                                         if (conf->assign_hook && str)
3659                                         {
3660                                                 const char *newstr;
3661
3662                                                 newstr = (*conf->assign_hook) (str, true,
3663                                                                                                            PGC_S_SESSION);
3664                                                 if (newstr == NULL)
3665                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3666                                                                  conf->gen.name, str);
3667                                                 else if (newstr != str)
3668                                                 {
3669                                                         /*
3670                                                          * See notes in set_config_option about casting
3671                                                          */
3672                                                         str = (char *) newstr;
3673                                                 }
3674                                         }
3675
3676                                         set_string_field(conf, conf->variable, str);
3677                                         break;
3678                                 }
3679                         case PGC_ENUM:
3680                                 {
3681                                         struct config_enum *conf = (struct config_enum *) gconf;
3682
3683                                         if (conf->assign_hook)
3684                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3685                                                                                                    PGC_S_SESSION))
3686                                                         elog(ERROR, "failed to reset %s to %s",
3687                                                                  conf->gen.name,
3688                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3689                                         *conf->variable = conf->reset_val;
3690                                         break;
3691                                 }
3692                 }
3693
3694                 gconf->source = gconf->reset_source;
3695
3696                 if (gconf->flags & GUC_REPORT)
3697                         ReportGUCOption(gconf);
3698         }
3699 }
3700
3701
3702 /*
3703  * push_old_value
3704  *              Push previous state during transactional assignment to a GUC variable.
3705  */
3706 static void
3707 push_old_value(struct config_generic * gconf, GucAction action)
3708 {
3709         GucStack   *stack;
3710
3711         /* If we're not inside a nest level, do nothing */
3712         if (GUCNestLevel == 0)
3713                 return;
3714
3715         /* Do we already have a stack entry of the current nest level? */
3716         stack = gconf->stack;
3717         if (stack && stack->nest_level >= GUCNestLevel)
3718         {
3719                 /* Yes, so adjust its state if necessary */
3720                 Assert(stack->nest_level == GUCNestLevel);
3721                 switch (action)
3722                 {
3723                         case GUC_ACTION_SET:
3724                                 /* SET overrides any prior action at same nest level */
3725                                 if (stack->state == GUC_SET_LOCAL)
3726                                 {
3727                                         /* must discard old masked value */
3728                                         discard_stack_value(gconf, &stack->masked);
3729                                 }
3730                                 stack->state = GUC_SET;
3731                                 break;
3732                         case GUC_ACTION_LOCAL:
3733                                 if (stack->state == GUC_SET)
3734                                 {
3735                                         /* SET followed by SET LOCAL, remember SET's value */
3736                                         set_stack_value(gconf, &stack->masked);
3737                                         stack->state = GUC_SET_LOCAL;
3738                                 }
3739                                 /* in all other cases, no change to stack entry */
3740                                 break;
3741                         case GUC_ACTION_SAVE:
3742                                 /* Could only have a prior SAVE of same variable */
3743                                 Assert(stack->state == GUC_SAVE);
3744                                 break;
3745                 }
3746                 Assert(guc_dirty);              /* must be set already */
3747                 return;
3748         }
3749
3750         /*
3751          * Push a new stack entry
3752          *
3753          * We keep all the stack entries in TopTransactionContext for simplicity.
3754          */
3755         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3756                                                                                                 sizeof(GucStack));
3757
3758         stack->prev = gconf->stack;
3759         stack->nest_level = GUCNestLevel;
3760         switch (action)
3761         {
3762                 case GUC_ACTION_SET:
3763                         stack->state = GUC_SET;
3764                         break;
3765                 case GUC_ACTION_LOCAL:
3766                         stack->state = GUC_LOCAL;
3767                         break;
3768                 case GUC_ACTION_SAVE:
3769                         stack->state = GUC_SAVE;
3770                         break;
3771         }
3772         stack->source = gconf->source;
3773         set_stack_value(gconf, &stack->prior);
3774
3775         gconf->stack = stack;
3776
3777         /* Ensure we remember to pop at end of xact */
3778         guc_dirty = true;
3779 }
3780
3781
3782 /*
3783  * Do GUC processing at main transaction start.
3784  */
3785 void
3786 AtStart_GUC(void)
3787 {
3788         /*
3789          * The nest level should be 0 between transactions; if it isn't, somebody
3790          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3791          * throw a warning but make no other effort to clean up.
3792          */
3793         if (GUCNestLevel != 0)
3794                 elog(WARNING, "GUC nest level = %d at transaction start",
3795                          GUCNestLevel);
3796         GUCNestLevel = 1;
3797 }
3798
3799 /*
3800  * Enter a new nesting level for GUC values.  This is called at subtransaction
3801  * start and when entering a function that has proconfig settings.      NOTE that
3802  * we must not risk error here, else subtransaction start will be unhappy.
3803  */
3804 int
3805 NewGUCNestLevel(void)
3806 {
3807         return ++GUCNestLevel;
3808 }
3809
3810 /*
3811  * Do GUC processing at transaction or subtransaction commit or abort, or
3812  * when exiting a function that has proconfig settings.  (The name is thus
3813  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3814  * During abort, we discard all GUC settings that were applied at nesting
3815  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3816  */
3817 void
3818 AtEOXact_GUC(bool isCommit, int nestLevel)
3819 {
3820         bool            still_dirty;
3821         int                     i;
3822
3823         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3824
3825         /* Quick exit if nothing's changed in this transaction */
3826         if (!guc_dirty)
3827         {
3828                 GUCNestLevel = nestLevel - 1;
3829                 return;
3830         }
3831
3832         still_dirty = false;
3833         for (i = 0; i < num_guc_variables; i++)
3834         {
3835                 struct config_generic *gconf = guc_variables[i];
3836                 GucStack   *stack;
3837
3838                 /*
3839                  * Process and pop each stack entry within the nest level.      To
3840                  * simplify fmgr_security_definer(), we allow failure exit from a
3841                  * function-with-SET-options to be recovered at the surrounding
3842                  * transaction or subtransaction abort; so there could be more than
3843                  * one stack entry to pop.
3844                  */
3845                 while ((stack = gconf->stack) != NULL &&
3846                            stack->nest_level >= nestLevel)
3847                 {
3848                         GucStack   *prev = stack->prev;
3849                         bool            restorePrior = false;
3850                         bool            restoreMasked = false;
3851                         bool            changed;
3852
3853                         /*
3854                          * In this next bit, if we don't set either restorePrior or
3855                          * restoreMasked, we must "discard" any unwanted fields of the
3856                          * stack entries to avoid leaking memory.  If we do set one of
3857                          * those flags, unused fields will be cleaned up after restoring.
3858                          */
3859                         if (!isCommit)          /* if abort, always restore prior value */
3860                                 restorePrior = true;
3861                         else if (stack->state == GUC_SAVE)
3862                                 restorePrior = true;
3863                         else if (stack->nest_level == 1)
3864                         {
3865                                 /* transaction commit */
3866                                 if (stack->state == GUC_SET_LOCAL)
3867                                         restoreMasked = true;
3868                                 else if (stack->state == GUC_SET)
3869                                 {
3870                                         /* we keep the current active value */
3871                                         discard_stack_value(gconf, &stack->prior);
3872                                 }
3873                                 else    /* must be GUC_LOCAL */
3874                                         restorePrior = true;
3875                         }
3876                         else if (prev == NULL ||
3877                                          prev->nest_level < stack->nest_level - 1)
3878                         {
3879                                 /* decrement entry's level and do not pop it */
3880                                 stack->nest_level--;
3881                                 continue;
3882                         }
3883                         else
3884                         {
3885                                 /*
3886                                  * We have to merge this stack entry into prev. See README for
3887                                  * discussion of this bit.
3888                                  */
3889                                 switch (stack->state)
3890                                 {
3891                                         case GUC_SAVE:
3892                                                 Assert(false);  /* can't get here */
3893
3894                                         case GUC_SET:
3895                                                 /* next level always becomes SET */
3896                                                 discard_stack_value(gconf, &stack->prior);
3897                                                 if (prev->state == GUC_SET_LOCAL)
3898                                                         discard_stack_value(gconf, &prev->masked);
3899                                                 prev->state = GUC_SET;
3900                                                 break;
3901
3902                                         case GUC_LOCAL:
3903                                                 if (prev->state == GUC_SET)
3904                                                 {
3905                                                         /* LOCAL migrates down */
3906                                                         prev->masked = stack->prior;
3907                                                         prev->state = GUC_SET_LOCAL;
3908                                                 }
3909                                                 else
3910                                                 {
3911                                                         /* else just forget this stack level */
3912                                                         discard_stack_value(gconf, &stack->prior);
3913                                                 }
3914                                                 break;
3915
3916                                         case GUC_SET_LOCAL:
3917                                                 /* prior state at this level no longer wanted */
3918                                                 discard_stack_value(gconf, &stack->prior);
3919                                                 /* copy down the masked state */
3920                                                 if (prev->state == GUC_SET_LOCAL)
3921                                                         discard_stack_value(gconf, &prev->masked);
3922                                                 prev->masked = stack->masked;
3923                                                 prev->state = GUC_SET_LOCAL;
3924                                                 break;
3925                                 }
3926                         }
3927
3928                         changed = false;
3929
3930                         if (restorePrior || restoreMasked)
3931                         {
3932                                 /* Perform appropriate restoration of the stacked value */
3933                                 union config_var_value newvalue;
3934                                 GucSource       newsource;
3935
3936                                 if (restoreMasked)
3937                                 {
3938                                         newvalue = stack->masked;
3939                                         newsource = PGC_S_SESSION;
3940                                 }
3941                                 else
3942                                 {
3943                                         newvalue = stack->prior;
3944                                         newsource = stack->source;
3945                                 }
3946
3947                                 switch (gconf->vartype)
3948                                 {
3949                                         case PGC_BOOL:
3950                                                 {
3951                                                         struct config_bool *conf = (struct config_bool *) gconf;
3952                                                         bool            newval = newvalue.boolval;
3953
3954                                                         if (*conf->variable != newval)
3955                                                         {
3956                                                                 if (conf->assign_hook)
3957                                                                         if (!(*conf->assign_hook) (newval,
3958                                                                                                            true, PGC_S_OVERRIDE))
3959                                                                                 elog(LOG, "failed to commit %s as %d",
3960                                                                                          conf->gen.name, (int) newval);
3961                                                                 *conf->variable = newval;
3962                                                                 changed = true;
3963                                                         }
3964                                                         break;
3965                                                 }
3966                                         case PGC_INT:
3967                                                 {
3968                                                         struct config_int *conf = (struct config_int *) gconf;
3969                                                         int                     newval = newvalue.intval;
3970
3971                                                         if (*conf->variable != newval)
3972                                                         {
3973                                                                 if (conf->assign_hook)
3974                                                                         if (!(*conf->assign_hook) (newval,
3975                                                                                                            true, PGC_S_OVERRIDE))
3976                                                                                 elog(LOG, "failed to commit %s as %d",
3977                                                                                          conf->gen.name, newval);
3978                                                                 *conf->variable = newval;
3979                                                                 changed = true;
3980                                                         }
3981                                                         break;
3982                                                 }
3983                                         case PGC_REAL:
3984                                                 {
3985                                                         struct config_real *conf = (struct config_real *) gconf;
3986                                                         double          newval = newvalue.realval;
3987
3988                                                         if (*conf->variable != newval)
3989                                                         {
3990                                                                 if (conf->assign_hook)
3991                                                                         if (!(*conf->assign_hook) (newval,
3992                                                                                                            true, PGC_S_OVERRIDE))
3993                                                                                 elog(LOG, "failed to commit %s as %g",
3994                                                                                          conf->gen.name, newval);
3995                                                                 *conf->variable = newval;
3996                                                                 changed = true;
3997                                                         }
3998                                                         break;
3999                                                 }
4000                                         case PGC_STRING:
4001                                                 {
4002                                                         struct config_string *conf = (struct config_string *) gconf;
4003                                                         char       *newval = newvalue.stringval;
4004
4005                                                         if (*conf->variable != newval)
4006                                                         {
4007                                                                 if (conf->assign_hook && newval)
4008                                                                 {
4009                                                                         const char *newstr;
4010
4011                                                                         newstr = (*conf->assign_hook) (newval, true,
4012                                                                                                                          PGC_S_OVERRIDE);
4013                                                                         if (newstr == NULL)
4014                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
4015                                                                                          conf->gen.name, newval);
4016                                                                         else if (newstr != newval)
4017                                                                         {
4018                                                                                 /*
4019                                                                                  * If newval should now be freed,
4020                                                                                  * it'll be taken care of below.
4021                                                                                  *
4022                                                                                  * See notes in set_config_option
4023                                                                                  * about casting
4024                                                                                  */
4025                                                                                 newval = (char *) newstr;
4026                                                                         }
4027                                                                 }
4028
4029                                                                 set_string_field(conf, conf->variable, newval);
4030                                                                 changed = true;
4031                                                         }
4032
4033                                                         /*
4034                                                          * Release stacked values if not used anymore. We
4035                                                          * could use discard_stack_value() here, but since
4036                                                          * we have type-specific code anyway, might as
4037                                                          * well inline it.
4038                                                          */
4039                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4040                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4041                                                         break;
4042                                                 }
4043                                         case PGC_ENUM:
4044                                                 {
4045                                                         struct config_enum *conf = (struct config_enum *) gconf;
4046                                                         int                     newval = newvalue.enumval;
4047
4048                                                         if (*conf->variable != newval)
4049                                                         {
4050                                                                 if (conf->assign_hook)
4051                                                                         if (!(*conf->assign_hook) (newval,
4052                                                                                                            true, PGC_S_OVERRIDE))
4053                                                                                 elog(LOG, "failed to commit %s as %s",
4054                                                                                          conf->gen.name,
4055                                                                                          config_enum_lookup_by_value(conf, newval));
4056                                                                 *conf->variable = newval;
4057                                                                 changed = true;
4058                                                         }
4059                                                         break;
4060                                                 }
4061                                 }
4062
4063                                 gconf->source = newsource;
4064                         }
4065
4066                         /* Finish popping the state stack */
4067                         gconf->stack = prev;
4068                         pfree(stack);
4069
4070                         /* Report new value if we changed it */
4071                         if (changed && (gconf->flags & GUC_REPORT))
4072                                 ReportGUCOption(gconf);
4073                 }                                               /* end of stack-popping loop */
4074
4075                 if (stack != NULL)
4076                         still_dirty = true;
4077         }
4078
4079         /* If there are no remaining stack entries, we can reset guc_dirty */
4080         guc_dirty = still_dirty;
4081
4082         /* Update nesting level */
4083         GUCNestLevel = nestLevel - 1;
4084 }
4085
4086
4087 /*
4088  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4089  * This is executed at completion of backend startup.
4090  */
4091 void
4092 BeginReportingGUCOptions(void)
4093 {
4094         int                     i;
4095
4096         /*
4097          * Don't do anything unless talking to an interactive frontend of protocol
4098          * 3.0 or later.
4099          */
4100         if (whereToSendOutput != DestRemote ||
4101                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4102                 return;
4103
4104         reporting_enabled = true;
4105
4106         /* Transmit initial values of interesting variables */
4107         for (i = 0; i < num_guc_variables; i++)
4108         {
4109                 struct config_generic *conf = guc_variables[i];
4110
4111                 if (conf->flags & GUC_REPORT)
4112                         ReportGUCOption(conf);
4113         }
4114 }
4115
4116 /*
4117  * ReportGUCOption: if appropriate, transmit option value to frontend
4118  */
4119 static void
4120 ReportGUCOption(struct config_generic * record)
4121 {
4122         if (reporting_enabled && (record->flags & GUC_REPORT))
4123         {
4124                 char       *val = _ShowOption(record, false);
4125                 StringInfoData msgbuf;
4126
4127                 pq_beginmessage(&msgbuf, 'S');
4128                 pq_sendstring(&msgbuf, record->name);
4129                 pq_sendstring(&msgbuf, val);
4130                 pq_endmessage(&msgbuf);
4131
4132                 pfree(val);
4133         }
4134 }
4135
4136 /*
4137  * Try to parse value as an integer.  The accepted formats are the
4138  * usual decimal, octal, or hexadecimal formats, optionally followed by
4139  * a unit name if "flags" indicates a unit is allowed.
4140  *
4141  * If the string parses okay, return true, else false.
4142  * If okay and result is not NULL, return the value in *result.
4143  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4144  *      HINT message, or NULL if no hint provided.
4145  */
4146 bool
4147 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4148 {
4149         int64           val;
4150         char       *endptr;
4151
4152         /* To suppress compiler warnings, always set output params */
4153         if (result)
4154                 *result = 0;
4155         if (hintmsg)
4156                 *hintmsg = NULL;
4157
4158         /* We assume here that int64 is at least as wide as long */
4159         errno = 0;
4160         val = strtol(value, &endptr, 0);
4161
4162         if (endptr == value)
4163                 return false;                   /* no HINT for integer syntax error */
4164
4165         if (errno == ERANGE || val != (int64) ((int32) val))
4166         {
4167                 if (hintmsg)
4168                         *hintmsg = gettext_noop("Value exceeds integer range.");
4169                 return false;
4170         }
4171
4172         /* allow whitespace between integer and unit */
4173         while (isspace((unsigned char) *endptr))
4174                 endptr++;
4175
4176         /* Handle possible unit */
4177         if (*endptr != '\0')
4178         {
4179                 /*
4180                  * Note: the multiple-switch coding technique here is a bit tedious,
4181                  * but seems necessary to avoid intermediate-value overflows.
4182                  *
4183                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4184                  * overflow due to units conversion, but there are few enough such
4185                  * machines that it does not seem worth trying to be smarter.
4186                  */
4187                 if (flags & GUC_UNIT_MEMORY)
4188                 {
4189                         /* Set hint for use if no match or trailing garbage */
4190                         if (hintmsg)
4191                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4192
4193 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4194 #error BLCKSZ must be between 1KB and 1MB
4195 #endif
4196 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4197 #error XLOG_BLCKSZ must be between 1KB and 1MB
4198 #endif
4199
4200                         if (strncmp(endptr, "kB", 2) == 0)
4201                         {
4202                                 endptr += 2;
4203                                 switch (flags & GUC_UNIT_MEMORY)
4204                                 {
4205                                         case GUC_UNIT_BLOCKS:
4206                                                 val /= (BLCKSZ / 1024);
4207                                                 break;
4208                                         case GUC_UNIT_XBLOCKS:
4209                                                 val /= (XLOG_BLCKSZ / 1024);
4210                                                 break;
4211                                 }
4212                         }
4213                         else if (strncmp(endptr, "MB", 2) == 0)
4214                         {
4215                                 endptr += 2;
4216                                 switch (flags & GUC_UNIT_MEMORY)
4217                                 {
4218                                         case GUC_UNIT_KB:
4219                                                 val *= KB_PER_MB;
4220                                                 break;
4221                                         case GUC_UNIT_BLOCKS:
4222                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4223                                                 break;
4224                                         case GUC_UNIT_XBLOCKS:
4225                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4226                                                 break;
4227                                 }
4228                         }
4229                         else if (strncmp(endptr, "GB", 2) == 0)
4230                         {
4231                                 endptr += 2;
4232                                 switch (flags & GUC_UNIT_MEMORY)
4233                                 {
4234                                         case GUC_UNIT_KB:
4235                                                 val *= KB_PER_GB;
4236                                                 break;
4237                                         case GUC_UNIT_BLOCKS:
4238                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4239                                                 break;
4240                                         case GUC_UNIT_XBLOCKS:
4241                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4242                                                 break;
4243                                 }
4244                         }
4245                 }
4246                 else if (flags & GUC_UNIT_TIME)
4247                 {
4248                         /* Set hint for use if no match or trailing garbage */
4249                         if (hintmsg)
4250                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4251
4252                         if (strncmp(endptr, "ms", 2) == 0)
4253                         {
4254                                 endptr += 2;
4255                                 switch (flags & GUC_UNIT_TIME)
4256                                 {
4257                                         case GUC_UNIT_S:
4258                                                 val /= MS_PER_S;
4259                                                 break;
4260                                         case GUC_UNIT_MIN:
4261                                                 val /= MS_PER_MIN;
4262                                                 break;
4263                                 }
4264                         }
4265                         else if (strncmp(endptr, "s", 1) == 0)
4266                         {
4267                                 endptr += 1;
4268                                 switch (flags & GUC_UNIT_TIME)
4269                                 {
4270                                         case GUC_UNIT_MS:
4271                                                 val *= MS_PER_S;
4272                                                 break;
4273                                         case GUC_UNIT_MIN:
4274                                                 val /= S_PER_MIN;
4275                                                 break;
4276                                 }
4277                         }
4278                         else if (strncmp(endptr, "min", 3) == 0)
4279                         {
4280                                 endptr += 3;
4281                                 switch (flags & GUC_UNIT_TIME)
4282                                 {
4283                                         case GUC_UNIT_MS:
4284                                                 val *= MS_PER_MIN;
4285                                                 break;
4286                                         case GUC_UNIT_S:
4287                                                 val *= S_PER_MIN;
4288                                                 break;
4289                                 }
4290                         }
4291                         else if (strncmp(endptr, "h", 1) == 0)
4292                         {
4293                                 endptr += 1;
4294                                 switch (flags & GUC_UNIT_TIME)
4295                                 {
4296                                         case GUC_UNIT_MS:
4297                                                 val *= MS_PER_H;
4298                                                 break;
4299                                         case GUC_UNIT_S:
4300                                                 val *= S_PER_H;
4301                                                 break;
4302                                         case GUC_UNIT_MIN:
4303                                                 val *= MIN_PER_H;
4304                                                 break;
4305                                 }
4306                         }
4307                         else if (strncmp(endptr, "d", 1) == 0)
4308                         {
4309                                 endptr += 1;
4310                                 switch (flags & GUC_UNIT_TIME)
4311                                 {
4312                                         case GUC_UNIT_MS:
4313                                                 val *= MS_PER_D;
4314                                                 break;
4315                                         case GUC_UNIT_S:
4316                                                 val *= S_PER_D;
4317                                                 break;
4318                                         case GUC_UNIT_MIN:
4319                                                 val *= MIN_PER_D;
4320                                                 break;
4321                                 }
4322                         }
4323                 }
4324
4325                 /* allow whitespace after unit */
4326                 while (isspace((unsigned char) *endptr))
4327                         endptr++;
4328
4329                 if (*endptr != '\0')
4330                         return false;           /* appropriate hint, if any, already set */
4331
4332                 /* Check for overflow due to units conversion */
4333                 if (val != (int64) ((int32) val))
4334                 {
4335                         if (hintmsg)
4336                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4337                         return false;
4338                 }
4339         }
4340
4341         if (result)
4342                 *result = (int) val;
4343         return true;
4344 }
4345
4346
4347
4348 /*
4349  * Try to parse value as a floating point number in the usual format.
4350  * If the string parses okay, return true, else false.
4351  * If okay and result is not NULL, return the value in *result.
4352  */
4353 bool
4354 parse_real(const char *value, double *result)
4355 {
4356         double          val;
4357         char       *endptr;
4358
4359         if (result)
4360                 *result = 0;                    /* suppress compiler warning */
4361
4362         errno = 0;
4363         val = strtod(value, &endptr);
4364         if (endptr == value || errno == ERANGE)
4365                 return false;
4366
4367         /* allow whitespace after number */
4368         while (isspace((unsigned char) *endptr))
4369                 endptr++;
4370         if (*endptr != '\0')
4371                 return false;
4372
4373         if (result)
4374                 *result = val;
4375         return true;
4376 }
4377
4378
4379 /*
4380  * Lookup the name for an enum option with the selected value.
4381  * Should only ever be called with known-valid values, so throws
4382  * an elog(ERROR) if the enum option is not found.
4383  *
4384  * The returned string is a pointer to static data and not
4385  * allocated for modification.
4386  */
4387 const char *
4388 config_enum_lookup_by_value(struct config_enum * record, int val)
4389 {
4390         const struct config_enum_entry *entry;
4391
4392         for (entry = record->options; entry && entry->name; entry++)
4393         {
4394                 if (entry->val == val)
4395                         return entry->name;
4396         }
4397
4398         elog(ERROR, "could not find enum option %d for %s",
4399                  val, record->gen.name);
4400         return NULL;                            /* silence compiler */
4401 }
4402
4403
4404 /*
4405  * Lookup the value for an enum option with the selected name
4406  * (case-insensitive).
4407  * If the enum option is found, sets the retval value and returns
4408  * true. If it's not found, return FALSE and retval is set to 0.
4409  */
4410 bool
4411 config_enum_lookup_by_name(struct config_enum * record, const char *value,
4412                                                    int *retval)
4413 {
4414         const struct config_enum_entry *entry;
4415
4416         for (entry = record->options; entry && entry->name; entry++)
4417         {
4418                 if (pg_strcasecmp(value, entry->name) == 0)
4419                 {
4420                         *retval = entry->val;
4421                         return TRUE;
4422                 }
4423         }
4424
4425         *retval = 0;
4426         return FALSE;
4427 }
4428
4429
4430 /*
4431  * Return a list of all available options for an enum, excluding
4432  * hidden ones, separated by the given separator.
4433  * If prefix is non-NULL, it is added before the first enum value.
4434  * If suffix is non-NULL, it is added to the end of the string.
4435  */
4436 static char *
4437 config_enum_get_options(struct config_enum * record, const char *prefix,
4438                                                 const char *suffix, const char *separator)
4439 {
4440         const struct config_enum_entry *entry;
4441         StringInfoData retstr;
4442         int                     seplen;
4443
4444         initStringInfo(&retstr);
4445         appendStringInfoString(&retstr, prefix);
4446
4447         seplen = strlen(separator);
4448         for (entry = record->options; entry && entry->name; entry++)
4449         {
4450                 if (!entry->hidden)
4451                 {
4452                         appendStringInfoString(&retstr, entry->name);
4453                         appendBinaryStringInfo(&retstr, separator, seplen);
4454                 }
4455         }
4456
4457         /*
4458          * All the entries may have been hidden, leaving the string empty if no
4459          * prefix was given. This indicates a broken GUC setup, since there is no
4460          * use for an enum without any values, so we just check to make sure we
4461          * don't write to invalid memory instead of actually trying to do
4462          * something smart with it.
4463          */
4464         if (retstr.len >= seplen)
4465         {
4466                 /* Replace final separator */
4467                 retstr.data[retstr.len - seplen] = '\0';
4468                 retstr.len -= seplen;
4469         }
4470
4471         appendStringInfoString(&retstr, suffix);
4472
4473         return retstr.data;
4474 }
4475
4476 /*
4477  * Call a GucStringAssignHook function, being careful to free the
4478  * "newval" string if the hook ereports.
4479  *
4480  * This is split out of set_config_option just to avoid the "volatile"
4481  * qualifiers that would otherwise have to be plastered all over.
4482  */
4483 static const char *
4484 call_string_assign_hook(GucStringAssignHook assign_hook,
4485                                                 char *newval, bool doit, GucSource source)
4486 {
4487         const char *result;
4488
4489         PG_TRY();
4490         {
4491                 result = (*assign_hook) (newval, doit, source);
4492         }
4493         PG_CATCH();
4494         {
4495                 free(newval);
4496                 PG_RE_THROW();
4497         }
4498         PG_END_TRY();
4499
4500         return result;
4501 }
4502
4503
4504 /*
4505  * Sets option `name' to given value. The value should be a string
4506  * which is going to be parsed and converted to the appropriate data
4507  * type.  The context and source parameters indicate in which context this
4508  * function is being called so it can apply the access restrictions
4509  * properly.
4510  *
4511  * If value is NULL, set the option to its default value (normally the
4512  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4513  *
4514  * action indicates whether to set the value globally in the session, locally
4515  * to the current top transaction, or just for the duration of a function call.
4516  *
4517  * If changeVal is false then don't really set the option but do all
4518  * the checks to see if it would work.
4519  *
4520  * If there is an error (non-existing option, invalid value) then an
4521  * ereport(ERROR) is thrown *unless* this is called in a context where we
4522  * don't want to ereport (currently, startup or SIGHUP config file reread).
4523  * In that case we write a suitable error message via ereport(LOG) and
4524  * return false. This is working around the deficiencies in the ereport
4525  * mechanism, so don't blame me.  In all other cases, the function
4526  * returns true, including cases where the input is valid but we chose
4527  * not to apply it because of context or source-priority considerations.
4528  *
4529  * See also SetConfigOption for an external interface.
4530  */
4531 bool
4532 set_config_option(const char *name, const char *value,
4533                                   GucContext context, GucSource source,
4534                                   GucAction action, bool changeVal)
4535 {
4536         struct config_generic *record;
4537         int                     elevel;
4538         bool            makeDefault;
4539
4540         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4541         {
4542                 /*
4543                  * To avoid cluttering the log, only the postmaster bleats loudly
4544                  * about problems with the config file.
4545                  */
4546                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4547         }
4548         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4549                 elevel = WARNING;
4550         else
4551                 elevel = ERROR;
4552
4553         record = find_option(name, true, elevel);
4554         if (record == NULL)
4555         {
4556                 ereport(elevel,
4557                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4558                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4559                 return false;
4560         }
4561
4562         /*
4563          * If source is postgresql.conf, mark the found record with
4564          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4565          * that we do it even if changeVal is false, since ProcessConfigFile wants
4566          * the marking to occur during its testing pass.
4567          */
4568         if (source == PGC_S_FILE)
4569                 record->status |= GUC_IS_IN_FILE;
4570
4571         /*
4572          * Check if the option can be set at this time. See guc.h for the precise
4573          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4574          * context. In that case we just ignore the attempt and return true.
4575          */
4576         switch (record->context)
4577         {
4578                 case PGC_INTERNAL:
4579                         if (context == PGC_SIGHUP)
4580                                 return true;
4581                         if (context != PGC_INTERNAL)
4582                         {
4583                                 ereport(elevel,
4584                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4585                                                  errmsg("parameter \"%s\" cannot be changed",
4586                                                                 name)));
4587                                 return false;
4588                         }
4589                         break;
4590                 case PGC_POSTMASTER:
4591                         if (context == PGC_SIGHUP)
4592                         {
4593                                 /*
4594                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4595                                  * We can't change the setting, so give a warning if the DBA
4596                                  * tries to change it.  (Throwing an error would be more
4597                                  * consistent, but seems overly rigid.)
4598                                  */
4599                                 if (changeVal && !is_newvalue_equal(record, value))
4600                                         ereport(elevel,
4601                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4602                                            errmsg("attempted change of parameter \"%s\" ignored",
4603                                                           name),
4604                                                          errdetail("This parameter cannot be changed after server start.")));
4605                                 return true;
4606                         }
4607                         if (context != PGC_POSTMASTER)
4608                         {
4609                                 ereport(elevel,
4610                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4611                                            errmsg("attempted change of parameter \"%s\" ignored",
4612                                                           name),
4613                                                  errdetail("This parameter cannot be changed after server start.")));
4614                                 return false;
4615                         }
4616                         break;
4617                 case PGC_SIGHUP:
4618                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4619                         {
4620                                 ereport(elevel,
4621                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4622                                                  errmsg("parameter \"%s\" cannot be changed now",
4623                                                                 name)));
4624                                 return false;
4625                         }
4626
4627                         /*
4628                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4629                          * can be changed after postmaster start". But there's nothing
4630                          * that prevents a crafty administrator from sending SIGHUP
4631                          * signals to individual backends only.
4632                          */
4633                         break;
4634                 case PGC_BACKEND:
4635                         if (context == PGC_SIGHUP)
4636                         {
4637                                 /*
4638                                  * If a PGC_BACKEND parameter is changed in the config file,
4639                                  * we want to accept the new value in the postmaster (whence
4640                                  * it will propagate to subsequently-started backends), but
4641                                  * ignore it in existing backends.      This is a tad klugy, but
4642                                  * necessary because we don't re-read the config file during
4643                                  * backend start.
4644                                  */
4645                                 if (IsUnderPostmaster)
4646                                         return true;
4647                         }
4648                         else if (context != PGC_POSTMASTER && context != PGC_BACKEND &&
4649                                          source != PGC_S_CLIENT)
4650                         {
4651                                 ereport(elevel,
4652                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4653                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4654                                                                 name)));
4655                                 return false;
4656                         }
4657                         break;
4658                 case PGC_SUSET:
4659                         if (context == PGC_USERSET || context == PGC_BACKEND)
4660                         {
4661                                 ereport(elevel,
4662                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4663                                                  errmsg("permission denied to set parameter \"%s\"",
4664                                                                 name)));
4665                                 return false;
4666                         }
4667                         break;
4668                 case PGC_USERSET:
4669                         /* always okay */
4670                         break;
4671         }
4672
4673         /*
4674          * Disallow changing GUC_NOT_WHILE_SEC_DEF values if we are inside a
4675          * security-definer function.  We can reject this regardless of
4676          * the context or source, mainly because sources that it might be
4677          * reasonable to override for won't be seen while inside a function.
4678          *
4679          * Note: variables marked GUC_NOT_WHILE_SEC_DEF should probably be marked
4680          * GUC_NO_RESET_ALL as well, because ResetAllOptions() doesn't check this.
4681          *
4682          * Note: this flag is currently used for "session_authorization" and
4683          * "role".  We need to prohibit this because when we exit the sec-def
4684          * context, GUC won't be notified, leaving things out of sync.
4685          *
4686          * XXX it would be nice to allow these cases in future, with the behavior
4687          * being that the SET's effects end when the security definer context is
4688          * exited.
4689          */
4690         if ((record->flags & GUC_NOT_WHILE_SEC_DEF) && InSecurityDefinerContext())
4691         {
4692                 ereport(elevel,
4693                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4694                                  errmsg("cannot set parameter \"%s\" within security-definer function",
4695                                                 name)));
4696                 return false;
4697         }
4698
4699         /*
4700          * Should we set reset/stacked values?  (If so, the behavior is not
4701          * transactional.)      This is done either when we get a default value from
4702          * the database's/user's/client's default settings or when we reset a
4703          * value to its default.
4704          */
4705         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4706                 ((value != NULL) || source == PGC_S_DEFAULT);
4707
4708         /*
4709          * Ignore attempted set if overridden by previously processed setting.
4710          * However, if changeVal is false then plow ahead anyway since we are
4711          * trying to find out if the value is potentially good, not actually use
4712          * it. Also keep going if makeDefault is true, since we may want to set
4713          * the reset/stacked values even if we can't set the variable itself.
4714          */
4715         if (record->source > source)
4716         {
4717                 if (changeVal && !makeDefault)
4718                 {
4719                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4720                                  name);
4721                         return true;
4722                 }
4723                 changeVal = false;
4724         }
4725
4726         /*
4727          * Evaluate value and set variable.
4728          */
4729         switch (record->vartype)
4730         {
4731                 case PGC_BOOL:
4732                         {
4733                                 struct config_bool *conf = (struct config_bool *) record;
4734                                 bool            newval;
4735
4736                                 if (value)
4737                                 {
4738                                         if (!parse_bool(value, &newval))
4739                                         {
4740                                                 ereport(elevel,
4741                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4742                                                   errmsg("parameter \"%s\" requires a Boolean value",
4743                                                                  name)));
4744                                                 return false;
4745                                         }
4746                                 }
4747                                 else if (source == PGC_S_DEFAULT)
4748                                         newval = conf->boot_val;
4749                                 else
4750                                 {
4751                                         newval = conf->reset_val;
4752                                         source = conf->gen.reset_source;
4753                                 }
4754
4755                                 /* Save old value to support transaction abort */
4756                                 if (changeVal && !makeDefault)
4757                                         push_old_value(&conf->gen, action);
4758
4759                                 if (conf->assign_hook)
4760                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4761                                         {
4762                                                 ereport(elevel,
4763                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4764                                                          errmsg("invalid value for parameter \"%s\": %d",
4765                                                                         name, (int) newval)));
4766                                                 return false;
4767                                         }
4768
4769                                 if (changeVal)
4770                                 {
4771                                         *conf->variable = newval;
4772                                         conf->gen.source = source;
4773                                 }
4774                                 if (makeDefault)
4775                                 {
4776                                         GucStack   *stack;
4777
4778                                         if (conf->gen.reset_source <= source)
4779                                         {
4780                                                 conf->reset_val = newval;
4781                                                 conf->gen.reset_source = source;
4782                                         }
4783                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4784                                         {
4785                                                 if (stack->source <= source)
4786                                                 {
4787                                                         stack->prior.boolval = newval;
4788                                                         stack->source = source;
4789                                                 }
4790                                         }
4791                                 }
4792                                 break;
4793                         }
4794
4795                 case PGC_INT:
4796                         {
4797                                 struct config_int *conf = (struct config_int *) record;
4798                                 int                     newval;
4799
4800                                 if (value)
4801                                 {
4802                                         const char *hintmsg;
4803
4804                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4805                                         {
4806                                                 ereport(elevel,
4807                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4808                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4809                                                                 name, value),
4810                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4811                                                 return false;
4812                                         }
4813                                         if (newval < conf->min || newval > conf->max)
4814                                         {
4815                                                 ereport(elevel,
4816                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4817                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4818                                                                                 newval, name, conf->min, conf->max)));
4819                                                 return false;
4820                                         }
4821                                 }
4822                                 else if (source == PGC_S_DEFAULT)
4823                                         newval = conf->boot_val;
4824                                 else
4825                                 {
4826                                         newval = conf->reset_val;
4827                                         source = conf->gen.reset_source;
4828                                 }
4829
4830                                 /* Save old value to support transaction abort */
4831                                 if (changeVal && !makeDefault)
4832                                         push_old_value(&conf->gen, action);
4833
4834                                 if (conf->assign_hook)
4835                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4836                                         {
4837                                                 ereport(elevel,
4838                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4839                                                          errmsg("invalid value for parameter \"%s\": %d",
4840                                                                         name, newval)));
4841                                                 return false;
4842                                         }
4843
4844                                 if (changeVal)
4845                                 {
4846                                         *conf->variable = newval;
4847                                         conf->gen.source = source;
4848                                 }
4849                                 if (makeDefault)
4850                                 {
4851                                         GucStack   *stack;
4852
4853                                         if (conf->gen.reset_source <= source)
4854                                         {
4855                                                 conf->reset_val = newval;
4856                                                 conf->gen.reset_source = source;
4857                                         }
4858                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4859                                         {
4860                                                 if (stack->source <= source)
4861                                                 {
4862                                                         stack->prior.intval = newval;
4863                                                         stack->source = source;
4864                                                 }
4865                                         }
4866                                 }
4867                                 break;
4868                         }
4869
4870                 case PGC_REAL:
4871                         {
4872                                 struct config_real *conf = (struct config_real *) record;
4873                                 double          newval;
4874
4875                                 if (value)
4876                                 {
4877                                         if (!parse_real(value, &newval))
4878                                         {
4879                                                 ereport(elevel,
4880                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4881                                                   errmsg("parameter \"%s\" requires a numeric value",
4882                                                                  name)));
4883                                                 return false;
4884                                         }
4885                                         if (newval < conf->min || newval > conf->max)
4886                                         {
4887                                                 ereport(elevel,
4888                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4889                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4890                                                                                 newval, name, conf->min, conf->max)));
4891                                                 return false;
4892                                         }
4893                                 }
4894                                 else if (source == PGC_S_DEFAULT)
4895                                         newval = conf->boot_val;
4896                                 else
4897                                 {
4898                                         newval = conf->reset_val;
4899                                         source = conf->gen.reset_source;
4900                                 }
4901
4902                                 /* Save old value to support transaction abort */
4903                                 if (changeVal && !makeDefault)
4904                                         push_old_value(&conf->gen, action);
4905
4906                                 if (conf->assign_hook)
4907                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4908                                         {
4909                                                 ereport(elevel,
4910                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4911                                                          errmsg("invalid value for parameter \"%s\": %g",
4912                                                                         name, newval)));
4913                                                 return false;
4914                                         }
4915
4916                                 if (changeVal)
4917                                 {
4918                                         *conf->variable = newval;
4919                                         conf->gen.source = source;
4920                                 }
4921                                 if (makeDefault)
4922                                 {
4923                                         GucStack   *stack;
4924
4925                                         if (conf->gen.reset_source <= source)
4926                                         {
4927                                                 conf->reset_val = newval;
4928                                                 conf->gen.reset_source = source;
4929                                         }
4930                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4931                                         {
4932                                                 if (stack->source <= source)
4933                                                 {
4934                                                         stack->prior.realval = newval;
4935                                                         stack->source = source;
4936                                                 }
4937                                         }
4938                                 }
4939                                 break;
4940                         }
4941
4942                 case PGC_STRING:
4943                         {
4944                                 struct config_string *conf = (struct config_string *) record;
4945                                 char       *newval;
4946
4947                                 if (value)
4948                                 {
4949                                         newval = guc_strdup(elevel, value);
4950                                         if (newval == NULL)
4951                                                 return false;
4952
4953                                         /*
4954                                          * The only sort of "parsing" check we need to do is apply
4955                                          * truncation if GUC_IS_NAME.
4956                                          */
4957                                         if (conf->gen.flags & GUC_IS_NAME)
4958                                                 truncate_identifier(newval, strlen(newval), true);
4959                                 }
4960                                 else if (source == PGC_S_DEFAULT)
4961                                 {
4962                                         if (conf->boot_val == NULL)
4963                                                 newval = NULL;
4964                                         else
4965                                         {
4966                                                 newval = guc_strdup(elevel, conf->boot_val);
4967                                                 if (newval == NULL)
4968                                                         return false;
4969                                         }
4970                                 }
4971                                 else
4972                                 {
4973                                         /*
4974                                          * We could possibly avoid strdup here, but easier to make
4975                                          * this case work the same as the normal assignment case;
4976                                          * note the possible free of newval below.
4977                                          */
4978                                         if (conf->reset_val == NULL)
4979                                                 newval = NULL;
4980                                         else
4981                                         {
4982                                                 newval = guc_strdup(elevel, conf->reset_val);
4983                                                 if (newval == NULL)
4984                                                         return false;
4985                                         }
4986                                         source = conf->gen.reset_source;
4987                                 }
4988
4989                                 /* Save old value to support transaction abort */
4990                                 if (changeVal && !makeDefault)
4991                                         push_old_value(&conf->gen, action);
4992
4993                                 if (conf->assign_hook && newval)
4994                                 {
4995                                         const char *hookresult;
4996
4997                                         /*
4998                                          * If the hook ereports, we have to make sure we free
4999                                          * newval, else it will be a permanent memory leak.
5000                                          */
5001                                         hookresult = call_string_assign_hook(conf->assign_hook,
5002                                                                                                                  newval,
5003                                                                                                                  changeVal,
5004                                                                                                                  source);
5005                                         if (hookresult == NULL)
5006                                         {
5007                                                 free(newval);
5008                                                 ereport(elevel,
5009                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5010                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5011                                                                 name, value ? value : "")));
5012                                                 return false;
5013                                         }
5014                                         else if (hookresult != newval)
5015                                         {
5016                                                 free(newval);
5017
5018                                                 /*
5019                                                  * Having to cast away const here is annoying, but the
5020                                                  * alternative is to declare assign_hooks as returning
5021                                                  * char*, which would mean they'd have to cast away
5022                                                  * const, or as both taking and returning char*, which
5023                                                  * doesn't seem attractive either --- we don't want
5024                                                  * them to scribble on the passed str.
5025                                                  */
5026                                                 newval = (char *) hookresult;
5027                                         }
5028                                 }
5029
5030                                 if (changeVal)
5031                                 {
5032                                         set_string_field(conf, conf->variable, newval);
5033                                         conf->gen.source = source;
5034                                 }
5035                                 if (makeDefault)
5036                                 {
5037                                         GucStack   *stack;
5038
5039                                         if (conf->gen.reset_source <= source)
5040                                         {
5041                                                 set_string_field(conf, &conf->reset_val, newval);
5042                                                 conf->gen.reset_source = source;
5043                                         }
5044                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5045                                         {
5046                                                 if (stack->source <= source)
5047                                                 {
5048                                                         set_string_field(conf, &stack->prior.stringval,
5049                                                                                          newval);
5050                                                         stack->source = source;
5051                                                 }
5052                                         }
5053                                 }
5054                                 /* Perhaps we didn't install newval anywhere */
5055                                 if (newval && !string_field_used(conf, newval))
5056                                         free(newval);
5057                                 break;
5058                         }
5059                 case PGC_ENUM:
5060                         {
5061                                 struct config_enum *conf = (struct config_enum *) record;
5062                                 int                     newval;
5063
5064                                 if (value)
5065                                 {
5066                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5067                                         {
5068                                                 char       *hintmsg;
5069
5070                                                 hintmsg = config_enum_get_options(conf,
5071                                                                                                                 "Available values: ",
5072                                                                                                                   ".", ", ");
5073
5074                                                 ereport(elevel,
5075                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5076                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5077                                                                 name, value),
5078                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5079
5080                                                 if (hintmsg)
5081                                                         pfree(hintmsg);
5082                                                 return false;
5083                                         }
5084                                 }
5085                                 else if (source == PGC_S_DEFAULT)
5086                                         newval = conf->boot_val;
5087                                 else
5088                                 {
5089                                         newval = conf->reset_val;
5090                                         source = conf->gen.reset_source;
5091                                 }
5092
5093                                 /* Save old value to support transaction abort */
5094                                 if (changeVal && !makeDefault)
5095                                         push_old_value(&conf->gen, action);
5096
5097                                 if (conf->assign_hook)
5098                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5099                                         {
5100                                                 ereport(elevel,
5101                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5102                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5103                                                                 name,
5104                                                                 config_enum_lookup_by_value(conf, newval))));
5105                                                 return false;
5106                                         }
5107
5108                                 if (changeVal)
5109                                 {
5110                                         *conf->variable = newval;
5111                                         conf->gen.source = source;
5112                                 }
5113                                 if (makeDefault)
5114                                 {
5115                                         GucStack   *stack;
5116
5117                                         if (conf->gen.reset_source <= source)
5118                                         {
5119                                                 conf->reset_val = newval;
5120                                                 conf->gen.reset_source = source;
5121                                         }
5122                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5123                                         {
5124                                                 if (stack->source <= source)
5125                                                 {
5126                                                         stack->prior.enumval = newval;
5127                                                         stack->source = source;
5128                                                 }
5129                                         }
5130                                 }
5131                                 break;
5132                         }
5133         }
5134
5135         if (changeVal && (record->flags & GUC_REPORT))
5136                 ReportGUCOption(record);
5137
5138         return true;
5139 }
5140
5141
5142 /*
5143  * Set the fields for source file and line number the setting came from.
5144  */
5145 static void
5146 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5147 {
5148         struct config_generic *record;
5149         int                     elevel;
5150
5151         /*
5152          * To avoid cluttering the log, only the postmaster bleats loudly about
5153          * problems with the config file.
5154          */
5155         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5156
5157         record = find_option(name, true, elevel);
5158         /* should not happen */
5159         if (record == NULL)
5160                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5161
5162         sourcefile = guc_strdup(elevel, sourcefile);
5163         if (record->sourcefile)
5164                 free(record->sourcefile);
5165         record->sourcefile = sourcefile;
5166         record->sourceline = sourceline;
5167 }
5168
5169 /*
5170  * Set a config option to the given value. See also set_config_option,
5171  * this is just the wrapper to be called from outside GUC.      NB: this
5172  * is used only for non-transactional operations.
5173  *
5174  * Note: there is no support here for setting source file/line, as it
5175  * is currently not needed.
5176  */
5177 void
5178 SetConfigOption(const char *name, const char *value,
5179                                 GucContext context, GucSource source)
5180 {
5181         (void) set_config_option(name, value, context, source,
5182                                                          GUC_ACTION_SET, true);
5183 }
5184
5185
5186
5187 /*
5188  * Fetch the current value of the option `name'. If the option doesn't exist,
5189  * throw an ereport and don't return.
5190  *
5191  * The string is *not* allocated for modification and is really only
5192  * valid until the next call to configuration related functions.
5193  */
5194 const char *
5195 GetConfigOption(const char *name)
5196 {
5197         struct config_generic *record;
5198         static char buffer[256];
5199
5200         record = find_option(name, false, ERROR);
5201         if (record == NULL)
5202                 ereport(ERROR,
5203                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5204                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5205         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5206                 ereport(ERROR,
5207                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5208                                  errmsg("must be superuser to examine \"%s\"", name)));
5209
5210         switch (record->vartype)
5211         {
5212                 case PGC_BOOL:
5213                         return *((struct config_bool *) record)->variable ? "on" : "off";
5214
5215                 case PGC_INT:
5216                         snprintf(buffer, sizeof(buffer), "%d",
5217                                          *((struct config_int *) record)->variable);
5218                         return buffer;
5219
5220                 case PGC_REAL:
5221                         snprintf(buffer, sizeof(buffer), "%g",
5222                                          *((struct config_real *) record)->variable);
5223                         return buffer;
5224
5225                 case PGC_STRING:
5226                         return *((struct config_string *) record)->variable;
5227
5228                 case PGC_ENUM:
5229                         return config_enum_lookup_by_value((struct config_enum *) record,
5230                                                                  *((struct config_enum *) record)->variable);
5231         }
5232         return NULL;
5233 }
5234
5235 /*
5236  * Get the RESET value associated with the given option.
5237  *
5238  * Note: this is not re-entrant, due to use of static result buffer;
5239  * not to mention that a string variable could have its reset_val changed.
5240  * Beware of assuming the result value is good for very long.
5241  */
5242 const char *
5243 GetConfigOptionResetString(const char *name)
5244 {
5245         struct config_generic *record;
5246         static char buffer[256];
5247
5248         record = find_option(name, false, ERROR);
5249         if (record == NULL)
5250                 ereport(ERROR,
5251                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5252                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5253         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5254                 ereport(ERROR,
5255                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5256                                  errmsg("must be superuser to examine \"%s\"", name)));
5257
5258         switch (record->vartype)
5259         {
5260                 case PGC_BOOL:
5261                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5262
5263                 case PGC_INT:
5264                         snprintf(buffer, sizeof(buffer), "%d",
5265                                          ((struct config_int *) record)->reset_val);
5266                         return buffer;
5267
5268                 case PGC_REAL:
5269                         snprintf(buffer, sizeof(buffer), "%g",
5270                                          ((struct config_real *) record)->reset_val);
5271                         return buffer;
5272
5273                 case PGC_STRING:
5274                         return ((struct config_string *) record)->reset_val;
5275
5276                 case PGC_ENUM:
5277                         return config_enum_lookup_by_value((struct config_enum *) record,
5278                                                                  ((struct config_enum *) record)->reset_val);
5279         }
5280         return NULL;
5281 }
5282
5283
5284 /*
5285  * GUC_complaint_elevel
5286  *              Get the ereport error level to use in an assign_hook's error report.
5287  *
5288  * This should be used by assign hooks that want to emit a custom error
5289  * report (in addition to the generic "invalid value for option FOO" that
5290  * guc.c will provide).  Note that the result might be ERROR or a lower
5291  * level, so the caller must be prepared for control to return from ereport,
5292  * or not.      If control does return, return false/NULL from the hook function.
5293  *
5294  * At some point it'd be nice to replace this with a mechanism that allows
5295  * the custom message to become the DETAIL line of guc.c's generic message.
5296  */
5297 int
5298 GUC_complaint_elevel(GucSource source)
5299 {
5300         int                     elevel;
5301
5302         if (source == PGC_S_FILE)
5303         {
5304                 /*
5305                  * To avoid cluttering the log, only the postmaster bleats loudly
5306                  * about problems with the config file.
5307                  */
5308                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5309         }
5310         else if (source == PGC_S_OVERRIDE)
5311         {
5312                 /*
5313                  * If we're a postmaster child, this is probably "undo" during
5314                  * transaction abort, so we don't want to clutter the log.  There's a
5315                  * small chance of a real problem with an OVERRIDE setting, though, so
5316                  * suppressing the message entirely wouldn't be desirable.
5317                  */
5318                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5319         }
5320         else if (source < PGC_S_INTERACTIVE)
5321                 elevel = LOG;
5322         else
5323                 elevel = ERROR;
5324
5325         return elevel;
5326 }
5327
5328
5329 /*
5330  * flatten_set_variable_args
5331  *              Given a parsenode List as emitted by the grammar for SET,
5332  *              convert to the flat string representation used by GUC.
5333  *
5334  * We need to be told the name of the variable the args are for, because
5335  * the flattening rules vary (ugh).
5336  *
5337  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5338  * a palloc'd string.
5339  */
5340 static char *
5341 flatten_set_variable_args(const char *name, List *args)
5342 {
5343         struct config_generic *record;
5344         int                     flags;
5345         StringInfoData buf;
5346         ListCell   *l;
5347
5348         /* Fast path if just DEFAULT */
5349         if (args == NIL)
5350                 return NULL;
5351
5352         /* Else get flags for the variable */
5353         record = find_option(name, true, ERROR);
5354         if (record == NULL)
5355                 ereport(ERROR,
5356                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5357                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5358
5359         flags = record->flags;
5360
5361         /* Complain if list input and non-list variable */
5362         if ((flags & GUC_LIST_INPUT) == 0 &&
5363                 list_length(args) != 1)
5364                 ereport(ERROR,
5365                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5366                                  errmsg("SET %s takes only one argument", name)));
5367
5368         initStringInfo(&buf);
5369
5370         /*
5371          * Each list member may be a plain A_Const node, or an A_Const within a
5372          * TypeCast; the latter case is supported only for ConstInterval arguments
5373          * (for SET TIME ZONE).
5374          */
5375         foreach(l, args)
5376         {
5377                 Node       *arg = (Node *) lfirst(l);
5378                 char       *val;
5379                 TypeName   *typeName = NULL;
5380                 A_Const    *con;
5381
5382                 if (l != list_head(args))
5383                         appendStringInfo(&buf, ", ");
5384
5385                 if (IsA(arg, TypeCast))
5386                 {
5387                         TypeCast   *tc = (TypeCast *) arg;
5388
5389                         arg = tc->arg;
5390                         typeName = tc->typeName;
5391                 }
5392
5393                 if (!IsA(arg, A_Const))
5394                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5395                 con = (A_Const *) arg;
5396
5397                 switch (nodeTag(&con->val))
5398                 {
5399                         case T_Integer:
5400                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5401                                 break;
5402                         case T_Float:
5403                                 /* represented as a string, so just copy it */
5404                                 appendStringInfoString(&buf, strVal(&con->val));
5405                                 break;
5406                         case T_String:
5407                                 val = strVal(&con->val);
5408                                 if (typeName != NULL)
5409                                 {
5410                                         /*
5411                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5412                                          * to interval and back to normalize the value and account
5413                                          * for any typmod.
5414                                          */
5415                                         Oid                     typoid;
5416                                         int32           typmod;
5417                                         Datum           interval;
5418                                         char       *intervalout;
5419
5420                                         typoid = typenameTypeId(NULL, typeName, &typmod);
5421                                         Assert(typoid == INTERVALOID);
5422
5423                                         interval =
5424                                                 DirectFunctionCall3(interval_in,
5425                                                                                         CStringGetDatum(val),
5426                                                                                         ObjectIdGetDatum(InvalidOid),
5427                                                                                         Int32GetDatum(typmod));
5428
5429                                         intervalout =
5430                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5431                                                                                                                         interval));
5432                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5433                                 }
5434                                 else
5435                                 {
5436                                         /*
5437                                          * Plain string literal or identifier.  For quote mode,
5438                                          * quote it if it's not a vanilla identifier.
5439                                          */
5440                                         if (flags & GUC_LIST_QUOTE)
5441                                                 appendStringInfoString(&buf, quote_identifier(val));
5442                                         else
5443                                                 appendStringInfoString(&buf, val);
5444                                 }
5445                                 break;
5446                         default:
5447                                 elog(ERROR, "unrecognized node type: %d",
5448                                          (int) nodeTag(&con->val));
5449                                 break;
5450                 }
5451         }
5452
5453         return buf.data;
5454 }
5455
5456
5457 /*
5458  * SET command
5459  */
5460 void
5461 ExecSetVariableStmt(VariableSetStmt *stmt)
5462 {
5463         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5464
5465         switch (stmt->kind)
5466         {
5467                 case VAR_SET_VALUE:
5468                 case VAR_SET_CURRENT:
5469                         set_config_option(stmt->name,
5470                                                           ExtractSetVariableArgs(stmt),
5471                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5472                                                           PGC_S_SESSION,
5473                                                           action,
5474                                                           true);
5475                         break;
5476                 case VAR_SET_MULTI:
5477
5478                         /*
5479                          * Special case for special SQL syntax that effectively sets more
5480                          * than one variable per statement.
5481                          */
5482                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5483                         {
5484                                 ListCell   *head;
5485
5486                                 foreach(head, stmt->args)
5487                                 {
5488                                         DefElem    *item = (DefElem *) lfirst(head);
5489
5490                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5491                                                 SetPGVariable("transaction_isolation",
5492                                                                           list_make1(item->arg), stmt->is_local);
5493                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5494                                                 SetPGVariable("transaction_read_only",
5495                                                                           list_make1(item->arg), stmt->is_local);
5496                                         else
5497                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5498                                                          item->defname);
5499                                 }
5500                         }
5501                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5502                         {
5503                                 ListCell   *head;
5504
5505                                 foreach(head, stmt->args)
5506                                 {
5507                                         DefElem    *item = (DefElem *) lfirst(head);
5508
5509                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5510                                                 SetPGVariable("default_transaction_isolation",
5511                                                                           list_make1(item->arg), stmt->is_local);
5512                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5513                                                 SetPGVariable("default_transaction_read_only",
5514                                                                           list_make1(item->arg), stmt->is_local);
5515                                         else
5516                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5517                                                          item->defname);
5518                                 }
5519                         }
5520                         else
5521                                 elog(ERROR, "unexpected SET MULTI element: %s",
5522                                          stmt->name);
5523                         break;
5524                 case VAR_SET_DEFAULT:
5525                 case VAR_RESET:
5526                         set_config_option(stmt->name,
5527                                                           NULL,
5528                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5529                                                           PGC_S_SESSION,
5530                                                           action,
5531                                                           true);
5532                         break;
5533                 case VAR_RESET_ALL:
5534                         ResetAllOptions();
5535                         break;
5536         }
5537 }
5538
5539 /*
5540  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5541  * The result is palloc'd.
5542  *
5543  * This is exported for use by actions such as ALTER ROLE SET.
5544  */
5545 char *
5546 ExtractSetVariableArgs(VariableSetStmt *stmt)
5547 {
5548         switch (stmt->kind)
5549         {
5550                 case VAR_SET_VALUE:
5551                         return flatten_set_variable_args(stmt->name, stmt->args);
5552                 case VAR_SET_CURRENT:
5553                         return GetConfigOptionByName(stmt->name, NULL);
5554                 default:
5555                         return NULL;
5556         }
5557 }
5558
5559 /*
5560  * SetPGVariable - SET command exported as an easily-C-callable function.
5561  *
5562  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5563  * by passing args == NIL), but not SET FROM CURRENT functionality.
5564  */
5565 void
5566 SetPGVariable(const char *name, List *args, bool is_local)
5567 {
5568         char       *argstring = flatten_set_variable_args(name, args);
5569
5570         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5571         set_config_option(name,
5572                                           argstring,
5573                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5574                                           PGC_S_SESSION,
5575                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5576                                           true);
5577 }
5578
5579 /*
5580  * SET command wrapped as a SQL callable function.
5581  */
5582 Datum
5583 set_config_by_name(PG_FUNCTION_ARGS)
5584 {
5585         char       *name;
5586         char       *value;
5587         char       *new_value;
5588         bool            is_local;
5589
5590         if (PG_ARGISNULL(0))
5591                 ereport(ERROR,
5592                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5593                                  errmsg("SET requires parameter name")));
5594
5595         /* Get the GUC variable name */
5596         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5597
5598         /* Get the desired value or set to NULL for a reset request */
5599         if (PG_ARGISNULL(1))
5600                 value = NULL;
5601         else
5602                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5603
5604         /*
5605          * Get the desired state of is_local. Default to false if provided value
5606          * is NULL
5607          */
5608         if (PG_ARGISNULL(2))
5609                 is_local = false;
5610         else
5611                 is_local = PG_GETARG_BOOL(2);
5612
5613         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5614         set_config_option(name,
5615                                           value,
5616                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5617                                           PGC_S_SESSION,
5618                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5619                                           true);
5620
5621         /* get the new current value */
5622         new_value = GetConfigOptionByName(name, NULL);
5623
5624         /* Convert return string to text */
5625         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5626 }
5627
5628
5629 /*
5630  * Common code for DefineCustomXXXVariable subroutines: allocate the
5631  * new variable's config struct and fill in generic fields.
5632  */
5633 static struct config_generic *
5634 init_custom_variable(const char *name,
5635                                          const char *short_desc,
5636                                          const char *long_desc,
5637                                          GucContext context,
5638                                          int flags,
5639                                          enum config_type type,
5640                                          size_t sz)
5641 {
5642         struct config_generic *gen;
5643
5644         /*
5645          * Only allow custom PGC_POSTMASTER variables to be created during shared
5646          * library preload; any later than that, we can't ensure that the value
5647          * doesn't change after startup.  This is a fatal elog if it happens; just
5648          * erroring out isn't safe because we don't know what the calling loadable
5649          * module might already have hooked into.
5650          */
5651         if (context == PGC_POSTMASTER &&
5652                 !process_shared_preload_libraries_in_progress)
5653                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5654
5655         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5656         memset(gen, 0, sz);
5657
5658         gen->name = guc_strdup(ERROR, name);
5659         gen->context = context;
5660         gen->group = CUSTOM_OPTIONS;
5661         gen->short_desc = short_desc;
5662         gen->long_desc = long_desc;
5663         gen->flags = flags;
5664         gen->vartype = type;
5665
5666         return gen;
5667 }
5668
5669 /*
5670  * Common code for DefineCustomXXXVariable subroutines: insert the new
5671  * variable into the GUC variable array, replacing any placeholder.
5672  */
5673 static void
5674 define_custom_variable(struct config_generic * variable)
5675 {
5676         const char *name = variable->name;
5677         const char **nameAddr = &name;
5678         const char *value;
5679         struct config_string *pHolder;
5680         GucContext      phcontext;
5681         struct config_generic **res;
5682
5683         /*
5684          * See if there's a placeholder by the same name.
5685          */
5686         res = (struct config_generic **) bsearch((void *) &nameAddr,
5687                                                                                          (void *) guc_variables,
5688                                                                                          num_guc_variables,
5689                                                                                          sizeof(struct config_generic *),
5690                                                                                          guc_var_compare);
5691         if (res == NULL)
5692         {
5693                 /*
5694                  * No placeholder to replace, so we can just add it ... but first,
5695                  * make sure it's initialized to its default value.
5696                  */
5697                 InitializeOneGUCOption(variable);
5698                 add_guc_variable(variable, ERROR);
5699                 return;
5700         }
5701
5702         /*
5703          * This better be a placeholder
5704          */
5705         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5706                 ereport(ERROR,
5707                                 (errcode(ERRCODE_INTERNAL_ERROR),
5708                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5709
5710         Assert((*res)->vartype == PGC_STRING);
5711         pHolder = (struct config_string *) (*res);
5712
5713         /*
5714          * First, set the variable to its default value.  We must do this even
5715          * though we intend to immediately apply a new value, since it's possible
5716          * that the new value is invalid.
5717          */
5718         InitializeOneGUCOption(variable);
5719
5720         /*
5721          * Replace the placeholder. We aren't changing the name, so no re-sorting
5722          * is necessary
5723          */
5724         *res = variable;
5725
5726         /*
5727          * Infer context for assignment based on source of existing value. We
5728          * can't tell this with exact accuracy, but we can at least do something
5729          * reasonable in typical cases.
5730          */
5731         switch (pHolder->gen.source)
5732         {
5733                 case PGC_S_DEFAULT:
5734                 case PGC_S_ENV_VAR:
5735                 case PGC_S_FILE:
5736                 case PGC_S_ARGV:
5737
5738                         /*
5739                          * If we got past the check in init_custom_variable, we can safely
5740                          * assume that any existing value for a PGC_POSTMASTER variable
5741                          * was set in postmaster context.
5742                          */
5743                         if (variable->context == PGC_POSTMASTER)
5744                                 phcontext = PGC_POSTMASTER;
5745                         else
5746                                 phcontext = PGC_SIGHUP;
5747                         break;
5748                 case PGC_S_DATABASE:
5749                 case PGC_S_USER:
5750                 case PGC_S_CLIENT:
5751                 case PGC_S_SESSION:
5752                 default:
5753                         phcontext = PGC_USERSET;
5754                         break;
5755         }
5756
5757         /*
5758          * Assign the string value stored in the placeholder to the real variable.
5759          *
5760          * XXX this is not really good enough --- it should be a nontransactional
5761          * assignment, since we don't want it to roll back if the current xact
5762          * fails later.  (Or do we?)
5763          */
5764         value = *pHolder->variable;
5765
5766         if (value)
5767         {
5768                 if (set_config_option(name, value,
5769                                                           phcontext, pHolder->gen.source,
5770                                                           GUC_ACTION_SET, true))
5771                 {
5772                         /* Also copy over any saved source-location information */
5773                         if (pHolder->gen.sourcefile)
5774                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5775                                                                           pHolder->gen.sourceline);
5776                 }
5777         }
5778
5779         /*
5780          * Free up as much as we conveniently can of the placeholder structure
5781          * (this neglects any stack items...)
5782          */
5783         set_string_field(pHolder, pHolder->variable, NULL);
5784         set_string_field(pHolder, &pHolder->reset_val, NULL);
5785
5786         free(pHolder);
5787 }
5788
5789 void
5790 DefineCustomBoolVariable(const char *name,
5791                                                  const char *short_desc,
5792                                                  const char *long_desc,
5793                                                  bool *valueAddr,
5794                                                  bool bootValue,
5795                                                  GucContext context,
5796                                                  int flags,
5797                                                  GucBoolAssignHook assign_hook,
5798                                                  GucShowHook show_hook)
5799 {
5800         struct config_bool *var;
5801
5802         var = (struct config_bool *)
5803                 init_custom_variable(name, short_desc, long_desc, context, flags,
5804                                                          PGC_BOOL, sizeof(struct config_bool));
5805         var->variable = valueAddr;
5806         var->boot_val = bootValue;
5807         var->reset_val = bootValue;
5808         var->assign_hook = assign_hook;
5809         var->show_hook = show_hook;
5810         define_custom_variable(&var->gen);
5811 }
5812
5813 void
5814 DefineCustomIntVariable(const char *name,
5815                                                 const char *short_desc,
5816                                                 const char *long_desc,
5817                                                 int *valueAddr,
5818                                                 int bootValue,
5819                                                 int minValue,
5820                                                 int maxValue,
5821                                                 GucContext context,
5822                                                 int flags,
5823                                                 GucIntAssignHook assign_hook,
5824                                                 GucShowHook show_hook)
5825 {
5826         struct config_int *var;
5827
5828         var = (struct config_int *)
5829                 init_custom_variable(name, short_desc, long_desc, context, flags,
5830                                                          PGC_INT, sizeof(struct config_int));
5831         var->variable = valueAddr;
5832         var->boot_val = bootValue;
5833         var->reset_val = bootValue;
5834         var->min = minValue;
5835         var->max = maxValue;
5836         var->assign_hook = assign_hook;
5837         var->show_hook = show_hook;
5838         define_custom_variable(&var->gen);
5839 }
5840
5841 void
5842 DefineCustomRealVariable(const char *name,
5843                                                  const char *short_desc,
5844                                                  const char *long_desc,
5845                                                  double *valueAddr,
5846                                                  double bootValue,
5847                                                  double minValue,
5848                                                  double maxValue,
5849                                                  GucContext context,
5850                                                  int flags,
5851                                                  GucRealAssignHook assign_hook,
5852                                                  GucShowHook show_hook)
5853 {
5854         struct config_real *var;
5855
5856         var = (struct config_real *)
5857                 init_custom_variable(name, short_desc, long_desc, context, flags,
5858                                                          PGC_REAL, sizeof(struct config_real));
5859         var->variable = valueAddr;
5860         var->boot_val = bootValue;
5861         var->reset_val = bootValue;
5862         var->min = minValue;
5863         var->max = maxValue;
5864         var->assign_hook = assign_hook;
5865         var->show_hook = show_hook;
5866         define_custom_variable(&var->gen);
5867 }
5868
5869 void
5870 DefineCustomStringVariable(const char *name,
5871                                                    const char *short_desc,
5872                                                    const char *long_desc,
5873                                                    char **valueAddr,
5874                                                    const char *bootValue,
5875                                                    GucContext context,
5876                                                    int flags,
5877                                                    GucStringAssignHook assign_hook,
5878                                                    GucShowHook show_hook)
5879 {
5880         struct config_string *var;
5881
5882         var = (struct config_string *)
5883                 init_custom_variable(name, short_desc, long_desc, context, flags,
5884                                                          PGC_STRING, sizeof(struct config_string));
5885         var->variable = valueAddr;
5886         var->boot_val = bootValue;
5887         /* we could probably do without strdup, but keep it like normal case */
5888         if (var->boot_val)
5889                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5890         var->assign_hook = assign_hook;
5891         var->show_hook = show_hook;
5892         define_custom_variable(&var->gen);
5893 }
5894
5895 void
5896 DefineCustomEnumVariable(const char *name,
5897                                                  const char *short_desc,
5898                                                  const char *long_desc,
5899                                                  int *valueAddr,
5900                                                  int bootValue,
5901                                                  const struct config_enum_entry * options,
5902                                                  GucContext context,
5903                                                  int flags,
5904                                                  GucEnumAssignHook assign_hook,
5905                                                  GucShowHook show_hook)
5906 {
5907         struct config_enum *var;
5908
5909         var = (struct config_enum *)
5910                 init_custom_variable(name, short_desc, long_desc, context, flags,
5911                                                          PGC_ENUM, sizeof(struct config_enum));
5912         var->variable = valueAddr;
5913         var->boot_val = bootValue;
5914         var->reset_val = bootValue;
5915         var->options = options;
5916         var->assign_hook = assign_hook;
5917         var->show_hook = show_hook;
5918         define_custom_variable(&var->gen);
5919 }
5920
5921 void
5922 EmitWarningsOnPlaceholders(const char *className)
5923 {
5924         int                     classLen = strlen(className);
5925         int                     i;
5926
5927         for (i = 0; i < num_guc_variables; i++)
5928         {
5929                 struct config_generic *var = guc_variables[i];
5930
5931                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5932                         strncmp(className, var->name, classLen) == 0 &&
5933                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5934                 {
5935                         ereport(WARNING,
5936                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5937                                          errmsg("unrecognized configuration parameter \"%s\"",
5938                                                         var->name)));
5939                 }
5940         }
5941 }
5942
5943
5944 /*
5945  * SHOW command
5946  */
5947 void
5948 GetPGVariable(const char *name, DestReceiver *dest)
5949 {
5950         if (guc_name_compare(name, "all") == 0)
5951                 ShowAllGUCConfig(dest);
5952         else
5953                 ShowGUCConfigOption(name, dest);
5954 }
5955
5956 TupleDesc
5957 GetPGVariableResultDesc(const char *name)
5958 {
5959         TupleDesc       tupdesc;
5960
5961         if (guc_name_compare(name, "all") == 0)
5962         {
5963                 /* need a tuple descriptor representing three TEXT columns */
5964                 tupdesc = CreateTemplateTupleDesc(3, false);
5965                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5966                                                    TEXTOID, -1, 0);
5967                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5968                                                    TEXTOID, -1, 0);
5969                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5970                                                    TEXTOID, -1, 0);
5971         }
5972         else
5973         {
5974                 const char *varname;
5975
5976                 /* Get the canonical spelling of name */
5977                 (void) GetConfigOptionByName(name, &varname);
5978
5979                 /* need a tuple descriptor representing a single TEXT column */
5980                 tupdesc = CreateTemplateTupleDesc(1, false);
5981                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5982                                                    TEXTOID, -1, 0);
5983         }
5984         return tupdesc;
5985 }
5986
5987
5988 /*
5989  * SHOW command
5990  */
5991 static void
5992 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5993 {
5994         TupOutputState *tstate;
5995         TupleDesc       tupdesc;
5996         const char *varname;
5997         char       *value;
5998
5999         /* Get the value and canonical spelling of name */
6000         value = GetConfigOptionByName(name, &varname);
6001
6002         /* need a tuple descriptor representing a single TEXT column */
6003         tupdesc = CreateTemplateTupleDesc(1, false);
6004         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
6005                                            TEXTOID, -1, 0);
6006
6007         /* prepare for projection of tuples */
6008         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6009
6010         /* Send it */
6011         do_text_output_oneline(tstate, value);
6012
6013         end_tup_output(tstate);
6014 }
6015
6016 /*
6017  * SHOW ALL command
6018  */
6019 static void
6020 ShowAllGUCConfig(DestReceiver *dest)
6021 {
6022         bool            am_superuser = superuser();
6023         int                     i;
6024         TupOutputState *tstate;
6025         TupleDesc       tupdesc;
6026         Datum       values[3];
6027         bool            isnull[3] = { false, false, false };
6028
6029         /* need a tuple descriptor representing three TEXT columns */
6030         tupdesc = CreateTemplateTupleDesc(3, false);
6031         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6032                                            TEXTOID, -1, 0);
6033         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6034                                            TEXTOID, -1, 0);
6035         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6036                                            TEXTOID, -1, 0);
6037
6038         /* prepare for projection of tuples */
6039         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6040
6041         for (i = 0; i < num_guc_variables; i++)
6042         {
6043                 struct config_generic *conf = guc_variables[i];
6044                 char   *setting;
6045
6046                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6047                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6048                         continue;
6049
6050                 /* assign to the values array */
6051                 values[0] = PointerGetDatum(cstring_to_text(conf->name));
6052
6053                 setting = _ShowOption(conf, true);
6054                 if (setting)
6055                 {
6056                         values[1] = PointerGetDatum(cstring_to_text(setting));
6057                         isnull[1] = false;
6058                 }
6059                 else
6060                 {
6061                         values[1] = PointerGetDatum(NULL);
6062                         isnull[1] = true;
6063                 }
6064
6065                 values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
6066
6067                 /* send it to dest */
6068                 do_tup_output(tstate, values, isnull);
6069
6070                 /* clean up */
6071                 pfree(DatumGetPointer(values[0]));
6072                 if (setting)
6073                 {
6074                         pfree(setting);
6075                         pfree(DatumGetPointer(values[1]));
6076                 }
6077                 pfree(DatumGetPointer(values[2]));
6078         }
6079
6080         end_tup_output(tstate);
6081 }
6082
6083 /*
6084  * Return GUC variable value by name; optionally return canonical
6085  * form of name.  Return value is palloc'd.
6086  */
6087 char *
6088 GetConfigOptionByName(const char *name, const char **varname)
6089 {
6090         struct config_generic *record;
6091
6092         record = find_option(name, false, ERROR);
6093         if (record == NULL)
6094                 ereport(ERROR,
6095                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6096                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6097         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6098                 ereport(ERROR,
6099                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6100                                  errmsg("must be superuser to examine \"%s\"", name)));
6101
6102         if (varname)
6103                 *varname = record->name;
6104
6105         return _ShowOption(record, true);
6106 }
6107
6108 /*
6109  * Return GUC variable value by variable number; optionally return canonical
6110  * form of name.  Return value is palloc'd.
6111  */
6112 void
6113 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6114 {
6115         char            buffer[256];
6116         struct config_generic *conf;
6117
6118         /* check requested variable number valid */
6119         Assert((varnum >= 0) && (varnum < num_guc_variables));
6120
6121         conf = guc_variables[varnum];
6122
6123         if (noshow)
6124         {
6125                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6126                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6127                         *noshow = true;
6128                 else
6129                         *noshow = false;
6130         }
6131
6132         /* first get the generic attributes */
6133
6134         /* name */
6135         values[0] = conf->name;
6136
6137         /* setting : use _ShowOption in order to avoid duplicating the logic */
6138         values[1] = _ShowOption(conf, false);
6139
6140         /* unit */
6141         if (conf->vartype == PGC_INT)
6142         {
6143                 static char buf[8];
6144
6145                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6146                 {
6147                         case GUC_UNIT_KB:
6148                                 values[2] = "kB";
6149                                 break;
6150                         case GUC_UNIT_BLOCKS:
6151                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6152                                 values[2] = buf;
6153                                 break;
6154                         case GUC_UNIT_XBLOCKS:
6155                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6156                                 values[2] = buf;
6157                                 break;
6158                         case GUC_UNIT_MS:
6159                                 values[2] = "ms";
6160                                 break;
6161                         case GUC_UNIT_S:
6162                                 values[2] = "s";
6163                                 break;
6164                         case GUC_UNIT_MIN:
6165                                 values[2] = "min";
6166                                 break;
6167                         default:
6168                                 values[2] = "";
6169                                 break;
6170                 }
6171         }
6172         else
6173                 values[2] = NULL;
6174
6175         /* group */
6176         values[3] = config_group_names[conf->group];
6177
6178         /* short_desc */
6179         values[4] = conf->short_desc;
6180
6181         /* extra_desc */
6182         values[5] = conf->long_desc;
6183
6184         /* context */
6185         values[6] = GucContext_Names[conf->context];
6186
6187         /* vartype */
6188         values[7] = config_type_names[conf->vartype];
6189
6190         /* source */
6191         values[8] = GucSource_Names[conf->source];
6192
6193         /* now get the type specifc attributes */
6194         switch (conf->vartype)
6195         {
6196                 case PGC_BOOL:
6197                         {
6198                                 struct config_bool *lconf = (struct config_bool *) conf;
6199
6200                                 /* min_val */
6201                                 values[9] = NULL;
6202
6203                                 /* max_val */
6204                                 values[10] = NULL;
6205
6206                                 /* enumvals */
6207                                 values[11] = NULL;
6208
6209                                 /* boot_val */
6210                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6211
6212                                 /* reset_val */
6213                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6214                         }
6215                         break;
6216
6217                 case PGC_INT:
6218                         {
6219                                 struct config_int *lconf = (struct config_int *) conf;
6220
6221                                 /* min_val */
6222                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6223                                 values[9] = pstrdup(buffer);
6224
6225                                 /* max_val */
6226                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6227                                 values[10] = pstrdup(buffer);
6228
6229                                 /* enumvals */
6230                                 values[11] = NULL;
6231
6232                                 /* boot_val */
6233                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6234                                 values[12] = pstrdup(buffer);
6235
6236                                 /* reset_val */
6237                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6238                                 values[13] = pstrdup(buffer);
6239                         }
6240                         break;
6241
6242                 case PGC_REAL:
6243                         {
6244                                 struct config_real *lconf = (struct config_real *) conf;
6245
6246                                 /* min_val */
6247                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6248                                 values[9] = pstrdup(buffer);
6249
6250                                 /* max_val */
6251                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6252                                 values[10] = pstrdup(buffer);
6253
6254                                 /* enumvals */
6255                                 values[11] = NULL;
6256
6257                                 /* boot_val */
6258                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6259                                 values[12] = pstrdup(buffer);
6260
6261                                 /* reset_val */
6262                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6263                                 values[13] = pstrdup(buffer);
6264                         }
6265                         break;
6266
6267                 case PGC_STRING:
6268                         {
6269                                 struct config_string *lconf = (struct config_string *) conf;
6270
6271                                 /* min_val */
6272                                 values[9] = NULL;
6273
6274                                 /* max_val */
6275                                 values[10] = NULL;
6276
6277                                 /* enumvals */
6278                                 values[11] = NULL;
6279
6280                                 /* boot_val */
6281                                 if (lconf->boot_val == NULL)
6282                                         values[12] = NULL;
6283                                 else
6284                                         values[12] = pstrdup(lconf->boot_val);
6285
6286                                 /* reset_val */
6287                                 if (lconf->reset_val == NULL)
6288                                         values[13] = NULL;
6289                                 else
6290                                         values[13] = pstrdup(lconf->reset_val);
6291                         }
6292                         break;
6293
6294                 case PGC_ENUM:
6295                         {
6296                                 struct config_enum *lconf = (struct config_enum *) conf;
6297
6298                                 /* min_val */
6299                                 values[9] = NULL;
6300
6301                                 /* max_val */
6302                                 values[10] = NULL;
6303
6304                                 /* enumvals */
6305
6306                                 /*
6307                                  * NOTE! enumvals with double quotes in them are not
6308                                  * supported!
6309                                  */
6310                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6311                                                                                                          "{\"", "\"}", "\",\"");
6312
6313                                 /* boot_val */
6314                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6315                                                                                                                    lconf->boot_val));
6316
6317                                 /* reset_val */
6318                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6319                                                                                                                   lconf->reset_val));
6320                         }
6321                         break;
6322
6323                 default:
6324                         {
6325                                 /*
6326                                  * should never get here, but in case we do, set 'em to NULL
6327                                  */
6328
6329                                 /* min_val */
6330                                 values[9] = NULL;
6331
6332                                 /* max_val */
6333                                 values[10] = NULL;
6334
6335                                 /* enumvals */
6336                                 values[11] = NULL;
6337
6338                                 /* boot_val */
6339                                 values[12] = NULL;
6340
6341                                 /* reset_val */
6342                                 values[13] = NULL;
6343                         }
6344                         break;
6345         }
6346
6347         /*
6348          * If the setting came from a config file, set the source location. For
6349          * security reasons, we don't show source file/line number for
6350          * non-superusers.
6351          */
6352         if (conf->source == PGC_S_FILE && superuser())
6353         {
6354                 values[14] = conf->sourcefile;
6355                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6356                 values[15] = pstrdup(buffer);
6357         }
6358         else
6359         {
6360                 values[14] = NULL;
6361                 values[15] = NULL;
6362         }
6363 }
6364
6365 /*
6366  * Return the total number of GUC variables
6367  */
6368 int
6369 GetNumConfigOptions(void)
6370 {
6371         return num_guc_variables;
6372 }
6373
6374 /*
6375  * show_config_by_name - equiv to SHOW X command but implemented as
6376  * a function.
6377  */
6378 Datum
6379 show_config_by_name(PG_FUNCTION_ARGS)
6380 {
6381         char       *varname;
6382         char       *varval;
6383
6384         /* Get the GUC variable name */
6385         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6386
6387         /* Get the value */
6388         varval = GetConfigOptionByName(varname, NULL);
6389
6390         /* Convert to text */
6391         PG_RETURN_TEXT_P(cstring_to_text(varval));
6392 }
6393
6394 /*
6395  * show_all_settings - equiv to SHOW ALL command but implemented as
6396  * a Table Function.
6397  */
6398 #define NUM_PG_SETTINGS_ATTS    16
6399
6400 Datum
6401 show_all_settings(PG_FUNCTION_ARGS)
6402 {
6403         FuncCallContext *funcctx;
6404         TupleDesc       tupdesc;
6405         int                     call_cntr;
6406         int                     max_calls;
6407         AttInMetadata *attinmeta;
6408         MemoryContext oldcontext;
6409
6410         /* stuff done only on the first call of the function */
6411         if (SRF_IS_FIRSTCALL())
6412         {
6413                 /* create a function context for cross-call persistence */
6414                 funcctx = SRF_FIRSTCALL_INIT();
6415
6416                 /*
6417                  * switch to memory context appropriate for multiple function calls
6418                  */
6419                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6420
6421                 /*
6422                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6423                  * of the appropriate types
6424                  */
6425                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6426                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6427                                                    TEXTOID, -1, 0);
6428                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6429                                                    TEXTOID, -1, 0);
6430                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6431                                                    TEXTOID, -1, 0);
6432                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6433                                                    TEXTOID, -1, 0);
6434                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6435                                                    TEXTOID, -1, 0);
6436                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6437                                                    TEXTOID, -1, 0);
6438                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6439                                                    TEXTOID, -1, 0);
6440                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6441                                                    TEXTOID, -1, 0);
6442                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6443                                                    TEXTOID, -1, 0);
6444                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6445                                                    TEXTOID, -1, 0);
6446                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6447                                                    TEXTOID, -1, 0);
6448                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6449                                                    TEXTARRAYOID, -1, 0);
6450                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6451                                                    TEXTOID, -1, 0);
6452                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6453                                                    TEXTOID, -1, 0);
6454                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6455                                                    TEXTOID, -1, 0);
6456                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6457                                                    INT4OID, -1, 0);
6458
6459                 /*
6460                  * Generate attribute metadata needed later to produce tuples from raw
6461                  * C strings
6462                  */
6463                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6464                 funcctx->attinmeta = attinmeta;
6465
6466                 /* total number of tuples to be returned */
6467                 funcctx->max_calls = GetNumConfigOptions();
6468
6469                 MemoryContextSwitchTo(oldcontext);
6470         }
6471
6472         /* stuff done on every call of the function */
6473         funcctx = SRF_PERCALL_SETUP();
6474
6475         call_cntr = funcctx->call_cntr;
6476         max_calls = funcctx->max_calls;
6477         attinmeta = funcctx->attinmeta;
6478
6479         if (call_cntr < max_calls)      /* do when there is more left to send */
6480         {
6481                 char       *values[NUM_PG_SETTINGS_ATTS];
6482                 bool            noshow;
6483                 HeapTuple       tuple;
6484                 Datum           result;
6485
6486                 /*
6487                  * Get the next visible GUC variable name and value
6488                  */
6489                 do
6490                 {
6491                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6492                         if (noshow)
6493                         {
6494                                 /* bump the counter and get the next config setting */
6495                                 call_cntr = ++funcctx->call_cntr;
6496
6497                                 /* make sure we haven't gone too far now */
6498                                 if (call_cntr >= max_calls)
6499                                         SRF_RETURN_DONE(funcctx);
6500                         }
6501                 } while (noshow);
6502
6503                 /* build a tuple */
6504                 tuple = BuildTupleFromCStrings(attinmeta, values);
6505
6506                 /* make the tuple into a datum */
6507                 result = HeapTupleGetDatum(tuple);
6508
6509                 SRF_RETURN_NEXT(funcctx, result);
6510         }
6511         else
6512         {
6513                 /* do when there is no more left */
6514                 SRF_RETURN_DONE(funcctx);
6515         }
6516 }
6517
6518 static char *
6519 _ShowOption(struct config_generic * record, bool use_units)
6520 {
6521         char            buffer[256];
6522         const char *val;
6523
6524         switch (record->vartype)
6525         {
6526                 case PGC_BOOL:
6527                         {
6528                                 struct config_bool *conf = (struct config_bool *) record;
6529
6530                                 if (conf->show_hook)
6531                                         val = (*conf->show_hook) ();
6532                                 else
6533                                         val = *conf->variable ? "on" : "off";
6534                         }
6535                         break;
6536
6537                 case PGC_INT:
6538                         {
6539                                 struct config_int *conf = (struct config_int *) record;
6540
6541                                 if (conf->show_hook)
6542                                         val = (*conf->show_hook) ();
6543                                 else
6544                                 {
6545                                         /*
6546                                          * Use int64 arithmetic to avoid overflows in units
6547                                          * conversion.  If INT64_IS_BUSTED we might overflow
6548                                          * anyway and print bogus answers, but there are few
6549                                          * enough such machines that it doesn't seem worth trying
6550                                          * harder.
6551                                          */
6552                                         int64           result = *conf->variable;
6553                                         const char *unit;
6554
6555                                         if (use_units && result > 0 &&
6556                                                 (record->flags & GUC_UNIT_MEMORY))
6557                                         {
6558                                                 switch (record->flags & GUC_UNIT_MEMORY)
6559                                                 {
6560                                                         case GUC_UNIT_BLOCKS:
6561                                                                 result *= BLCKSZ / 1024;
6562                                                                 break;
6563                                                         case GUC_UNIT_XBLOCKS:
6564                                                                 result *= XLOG_BLCKSZ / 1024;
6565                                                                 break;
6566                                                 }
6567
6568                                                 if (result % KB_PER_GB == 0)
6569                                                 {
6570                                                         result /= KB_PER_GB;
6571                                                         unit = "GB";
6572                                                 }
6573                                                 else if (result % KB_PER_MB == 0)
6574                                                 {
6575                                                         result /= KB_PER_MB;
6576                                                         unit = "MB";
6577                                                 }
6578                                                 else
6579                                                 {
6580                                                         unit = "kB";
6581                                                 }
6582                                         }
6583                                         else if (use_units && result > 0 &&
6584                                                          (record->flags & GUC_UNIT_TIME))
6585                                         {
6586                                                 switch (record->flags & GUC_UNIT_TIME)
6587                                                 {
6588                                                         case GUC_UNIT_S:
6589                                                                 result *= MS_PER_S;
6590                                                                 break;
6591                                                         case GUC_UNIT_MIN:
6592                                                                 result *= MS_PER_MIN;
6593                                                                 break;
6594                                                 }
6595
6596                                                 if (result % MS_PER_D == 0)
6597                                                 {
6598                                                         result /= MS_PER_D;
6599                                                         unit = "d";
6600                                                 }
6601                                                 else if (result % MS_PER_H == 0)
6602                                                 {
6603                                                         result /= MS_PER_H;
6604                                                         unit = "h";
6605                                                 }
6606                                                 else if (result % MS_PER_MIN == 0)
6607                                                 {
6608                                                         result /= MS_PER_MIN;
6609                                                         unit = "min";
6610                                                 }
6611                                                 else if (result % MS_PER_S == 0)
6612                                                 {
6613                                                         result /= MS_PER_S;
6614                                                         unit = "s";
6615                                                 }
6616                                                 else
6617                                                 {
6618                                                         unit = "ms";
6619                                                 }
6620                                         }
6621                                         else
6622                                                 unit = "";
6623
6624                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6625                                                          result, unit);
6626                                         val = buffer;
6627                                 }
6628                         }
6629                         break;
6630
6631                 case PGC_REAL:
6632                         {
6633                                 struct config_real *conf = (struct config_real *) record;
6634
6635                                 if (conf->show_hook)
6636                                         val = (*conf->show_hook) ();
6637                                 else
6638                                 {
6639                                         snprintf(buffer, sizeof(buffer), "%g",
6640                                                          *conf->variable);
6641                                         val = buffer;
6642                                 }
6643                         }
6644                         break;
6645
6646                 case PGC_STRING:
6647                         {
6648                                 struct config_string *conf = (struct config_string *) record;
6649
6650                                 if (conf->show_hook)
6651                                         val = (*conf->show_hook) ();
6652                                 else if (*conf->variable && **conf->variable)
6653                                         val = *conf->variable;
6654                                 else
6655                                         val = "";
6656                         }
6657                         break;
6658
6659                 case PGC_ENUM:
6660                         {
6661                                 struct config_enum *conf = (struct config_enum *) record;
6662
6663                                 if (conf->show_hook)
6664                                         val = (*conf->show_hook) ();
6665                                 else
6666                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6667                         }
6668                         break;
6669
6670                 default:
6671                         /* just to keep compiler quiet */
6672                         val = "???";
6673                         break;
6674         }
6675
6676         return pstrdup(val);
6677 }
6678
6679
6680 /*
6681  * Attempt (badly) to detect if a proposed new GUC setting is the same
6682  * as the current value.
6683  *
6684  * XXX this does not really work because it doesn't account for the
6685  * effects of canonicalization of string values by assign_hooks.
6686  */
6687 static bool
6688 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6689 {
6690         /* newvalue == NULL isn't supported */
6691         Assert(newvalue != NULL);
6692
6693         switch (record->vartype)
6694         {
6695                 case PGC_BOOL:
6696                         {
6697                                 struct config_bool *conf = (struct config_bool *) record;
6698                                 bool            newval;
6699
6700                                 return parse_bool(newvalue, &newval)
6701                                         && *conf->variable == newval;
6702                         }
6703                 case PGC_INT:
6704                         {
6705                                 struct config_int *conf = (struct config_int *) record;
6706                                 int                     newval;
6707
6708                                 return parse_int(newvalue, &newval, record->flags, NULL)
6709                                         && *conf->variable == newval;
6710                         }
6711                 case PGC_REAL:
6712                         {
6713                                 struct config_real *conf = (struct config_real *) record;
6714                                 double          newval;
6715
6716                                 return parse_real(newvalue, &newval)
6717                                         && *conf->variable == newval;
6718                         }
6719                 case PGC_STRING:
6720                         {
6721                                 struct config_string *conf = (struct config_string *) record;
6722
6723                                 return *conf->variable != NULL &&
6724                                         strcmp(*conf->variable, newvalue) == 0;
6725                         }
6726
6727                 case PGC_ENUM:
6728                         {
6729                                 struct config_enum *conf = (struct config_enum *) record;
6730                                 int                     newval;
6731
6732                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6733                                         *conf->variable == newval;
6734                         }
6735         }
6736
6737         return false;
6738 }
6739
6740
6741 #ifdef EXEC_BACKEND
6742
6743 /*
6744  *      These routines dump out all non-default GUC options into a binary
6745  *      file that is read by all exec'ed backends.  The format is:
6746  *
6747  *              variable name, string, null terminated
6748  *              variable value, string, null terminated
6749  *              variable source, integer
6750  */
6751 static void
6752 write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
6753 {
6754         if (gconf->source == PGC_S_DEFAULT)
6755                 return;
6756
6757         fprintf(fp, "%s", gconf->name);
6758         fputc(0, fp);
6759
6760         switch (gconf->vartype)
6761         {
6762                 case PGC_BOOL:
6763                         {
6764                                 struct config_bool *conf = (struct config_bool *) gconf;
6765
6766                                 if (*conf->variable)
6767                                         fprintf(fp, "true");
6768                                 else
6769                                         fprintf(fp, "false");
6770                         }
6771                         break;
6772
6773                 case PGC_INT:
6774                         {
6775                                 struct config_int *conf = (struct config_int *) gconf;
6776
6777                                 fprintf(fp, "%d", *conf->variable);
6778                         }
6779                         break;
6780
6781                 case PGC_REAL:
6782                         {
6783                                 struct config_real *conf = (struct config_real *) gconf;
6784
6785                                 /* Could lose precision here? */
6786                                 fprintf(fp, "%f", *conf->variable);
6787                         }
6788                         break;
6789
6790                 case PGC_STRING:
6791                         {
6792                                 struct config_string *conf = (struct config_string *) gconf;
6793
6794                                 fprintf(fp, "%s", *conf->variable);
6795                         }
6796                         break;
6797
6798                 case PGC_ENUM:
6799                         {
6800                                 struct config_enum *conf = (struct config_enum *) gconf;
6801
6802                                 fprintf(fp, "%s",
6803                                                 config_enum_lookup_by_value(conf, *conf->variable));
6804                         }
6805                         break;
6806         }
6807
6808         fputc(0, fp);
6809
6810         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6811 }
6812
6813 void
6814 write_nondefault_variables(GucContext context)
6815 {
6816         int                     elevel;
6817         FILE       *fp;
6818         struct config_generic *cvc_conf;
6819         int                     i;
6820
6821         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6822
6823         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6824
6825         /*
6826          * Open file
6827          */
6828         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6829         if (!fp)
6830         {
6831                 ereport(elevel,
6832                                 (errcode_for_file_access(),
6833                                  errmsg("could not write to file \"%s\": %m",
6834                                                 CONFIG_EXEC_PARAMS_NEW)));
6835                 return;
6836         }
6837
6838         /*
6839          * custom_variable_classes must be written out first; otherwise we might
6840          * reject custom variable values while reading the file.
6841          */
6842         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6843         if (cvc_conf)
6844                 write_one_nondefault_variable(fp, cvc_conf);
6845
6846         for (i = 0; i < num_guc_variables; i++)
6847         {
6848                 struct config_generic *gconf = guc_variables[i];
6849
6850                 if (gconf != cvc_conf)
6851                         write_one_nondefault_variable(fp, gconf);
6852         }
6853
6854         if (FreeFile(fp))
6855         {
6856                 ereport(elevel,
6857                                 (errcode_for_file_access(),
6858                                  errmsg("could not write to file \"%s\": %m",
6859                                                 CONFIG_EXEC_PARAMS_NEW)));
6860                 return;
6861         }
6862
6863         /*
6864          * Put new file in place.  This could delay on Win32, but we don't hold
6865          * any exclusive locks.
6866          */
6867         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6868 }
6869
6870
6871 /*
6872  *      Read string, including null byte from file
6873  *
6874  *      Return NULL on EOF and nothing read
6875  */
6876 static char *
6877 read_string_with_null(FILE *fp)
6878 {
6879         int                     i = 0,
6880                                 ch,
6881                                 maxlen = 256;
6882         char       *str = NULL;
6883
6884         do
6885         {
6886                 if ((ch = fgetc(fp)) == EOF)
6887                 {
6888                         if (i == 0)
6889                                 return NULL;
6890                         else
6891                                 elog(FATAL, "invalid format of exec config params file");
6892                 }
6893                 if (i == 0)
6894                         str = guc_malloc(FATAL, maxlen);
6895                 else if (i == maxlen)
6896                         str = guc_realloc(FATAL, str, maxlen *= 2);
6897                 str[i++] = ch;
6898         } while (ch != 0);
6899
6900         return str;
6901 }
6902
6903
6904 /*
6905  *      This routine loads a previous postmaster dump of its non-default
6906  *      settings.
6907  */
6908 void
6909 read_nondefault_variables(void)
6910 {
6911         FILE       *fp;
6912         char       *varname,
6913                            *varvalue;
6914         int                     varsource;
6915
6916         /*
6917          * Open file
6918          */
6919         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6920         if (!fp)
6921         {
6922                 /* File not found is fine */
6923                 if (errno != ENOENT)
6924                         ereport(FATAL,
6925                                         (errcode_for_file_access(),
6926                                          errmsg("could not read from file \"%s\": %m",
6927                                                         CONFIG_EXEC_PARAMS)));
6928                 return;
6929         }
6930
6931         for (;;)
6932         {
6933                 struct config_generic *record;
6934
6935                 if ((varname = read_string_with_null(fp)) == NULL)
6936                         break;
6937
6938                 if ((record = find_option(varname, true, FATAL)) == NULL)
6939                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6940                 if ((varvalue = read_string_with_null(fp)) == NULL)
6941                         elog(FATAL, "invalid format of exec config params file");
6942                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6943                         elog(FATAL, "invalid format of exec config params file");
6944
6945                 (void) set_config_option(varname, varvalue, record->context,
6946                                                                  varsource, GUC_ACTION_SET, true);
6947                 free(varname);
6948                 free(varvalue);
6949         }
6950
6951         FreeFile(fp);
6952 }
6953 #endif   /* EXEC_BACKEND */
6954
6955
6956 /*
6957  * A little "long argument" simulation, although not quite GNU
6958  * compliant. Takes a string of the form "some-option=some value" and
6959  * returns name = "some_option" and value = "some value" in malloc'ed
6960  * storage. Note that '-' is converted to '_' in the option name. If
6961  * there is no '=' in the input string then value will be NULL.
6962  */
6963 void
6964 ParseLongOption(const char *string, char **name, char **value)
6965 {
6966         size_t          equal_pos;
6967         char       *cp;
6968
6969         AssertArg(string);
6970         AssertArg(name);
6971         AssertArg(value);
6972
6973         equal_pos = strcspn(string, "=");
6974
6975         if (string[equal_pos] == '=')
6976         {
6977                 *name = guc_malloc(FATAL, equal_pos + 1);
6978                 strlcpy(*name, string, equal_pos + 1);
6979
6980                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6981         }
6982         else
6983         {
6984                 /* no equal sign in string */
6985                 *name = guc_strdup(FATAL, string);
6986                 *value = NULL;
6987         }
6988
6989         for (cp = *name; *cp; cp++)
6990                 if (*cp == '-')
6991                         *cp = '_';
6992 }
6993
6994
6995 /*
6996  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6997  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6998  *
6999  * The array parameter must be an array of TEXT (it must not be NULL).
7000  */
7001 void
7002 ProcessGUCArray(ArrayType *array,
7003                                 GucContext context, GucSource source, GucAction action)
7004 {
7005         int                     i;
7006
7007         Assert(array != NULL);
7008         Assert(ARR_ELEMTYPE(array) == TEXTOID);
7009         Assert(ARR_NDIM(array) == 1);
7010         Assert(ARR_LBOUND(array)[0] == 1);
7011
7012         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7013         {
7014                 Datum           d;
7015                 bool            isnull;
7016                 char       *s;
7017                 char       *name;
7018                 char       *value;
7019
7020                 d = array_ref(array, 1, &i,
7021                                           -1 /* varlenarray */ ,
7022                                           -1 /* TEXT's typlen */ ,
7023                                           false /* TEXT's typbyval */ ,
7024                                           'i' /* TEXT's typalign */ ,
7025                                           &isnull);
7026
7027                 if (isnull)
7028                         continue;
7029
7030                 s = TextDatumGetCString(d);
7031
7032                 ParseLongOption(s, &name, &value);
7033                 if (!value)
7034                 {
7035                         ereport(WARNING,
7036                                         (errcode(ERRCODE_SYNTAX_ERROR),
7037                                          errmsg("could not parse setting for parameter \"%s\"",
7038                                                         name)));
7039                         free(name);
7040                         continue;
7041                 }
7042
7043                 (void) set_config_option(name, value, context, source, action, true);
7044
7045                 free(name);
7046                 if (value)
7047                         free(value);
7048         }
7049 }
7050
7051
7052 /*
7053  * Add an entry to an option array.  The array parameter may be NULL
7054  * to indicate the current table entry is NULL.
7055  */
7056 ArrayType *
7057 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7058 {
7059         const char *varname;
7060         Datum           datum;
7061         char       *newval;
7062         ArrayType  *a;
7063
7064         Assert(name);
7065         Assert(value);
7066
7067         /* test if the option is valid */
7068         set_config_option(name, value,
7069                                           superuser() ? PGC_SUSET : PGC_USERSET,
7070                                           PGC_S_TEST, GUC_ACTION_SET, false);
7071
7072         /* convert name to canonical spelling, so we can use plain strcmp */
7073         (void) GetConfigOptionByName(name, &varname);
7074         name = varname;
7075
7076         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7077         sprintf(newval, "%s=%s", name, value);
7078         datum = CStringGetTextDatum(newval);
7079
7080         if (array)
7081         {
7082                 int                     index;
7083                 bool            isnull;
7084                 int                     i;
7085
7086                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7087                 Assert(ARR_NDIM(array) == 1);
7088                 Assert(ARR_LBOUND(array)[0] == 1);
7089
7090                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7091
7092                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7093                 {
7094                         Datum           d;
7095                         char       *current;
7096
7097                         d = array_ref(array, 1, &i,
7098                                                   -1 /* varlenarray */ ,
7099                                                   -1 /* TEXT's typlen */ ,
7100                                                   false /* TEXT's typbyval */ ,
7101                                                   'i' /* TEXT's typalign */ ,
7102                                                   &isnull);
7103                         if (isnull)
7104                                 continue;
7105                         current = TextDatumGetCString(d);
7106                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7107                         {
7108                                 index = i;
7109                                 break;
7110                         }
7111                 }
7112
7113                 a = array_set(array, 1, &index,
7114                                           datum,
7115                                           false,
7116                                           -1 /* varlena array */ ,
7117                                           -1 /* TEXT's typlen */ ,
7118                                           false /* TEXT's typbyval */ ,
7119                                           'i' /* TEXT's typalign */ );
7120         }
7121         else
7122                 a = construct_array(&datum, 1,
7123                                                         TEXTOID,
7124                                                         -1, false, 'i');
7125
7126         return a;
7127 }
7128
7129
7130 /*
7131  * Delete an entry from an option array.  The array parameter may be NULL
7132  * to indicate the current table entry is NULL.  Also, if the return value
7133  * is NULL then a null should be stored.
7134  */
7135 ArrayType *
7136 GUCArrayDelete(ArrayType *array, const char *name)
7137 {
7138         const char *varname;
7139         ArrayType  *newarray;
7140         int                     i;
7141         int                     index;
7142
7143         Assert(name);
7144
7145         /* test if the option is valid */
7146         set_config_option(name, NULL,
7147                                           superuser() ? PGC_SUSET : PGC_USERSET,
7148                                           PGC_S_TEST, GUC_ACTION_SET, false);
7149
7150         /* convert name to canonical spelling, so we can use plain strcmp */
7151         (void) GetConfigOptionByName(name, &varname);
7152         name = varname;
7153
7154         /* if array is currently null, then surely nothing to delete */
7155         if (!array)
7156                 return NULL;
7157
7158         newarray = NULL;
7159         index = 1;
7160
7161         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7162         {
7163                 Datum           d;
7164                 char       *val;
7165                 bool            isnull;
7166
7167                 d = array_ref(array, 1, &i,
7168                                           -1 /* varlenarray */ ,
7169                                           -1 /* TEXT's typlen */ ,
7170                                           false /* TEXT's typbyval */ ,
7171                                           'i' /* TEXT's typalign */ ,
7172                                           &isnull);
7173                 if (isnull)
7174                         continue;
7175                 val = TextDatumGetCString(d);
7176
7177                 /* ignore entry if it's what we want to delete */
7178                 if (strncmp(val, name, strlen(name)) == 0
7179                         && val[strlen(name)] == '=')
7180                         continue;
7181
7182                 /* else add it to the output array */
7183                 if (newarray)
7184                 {
7185                         newarray = array_set(newarray, 1, &index,
7186                                                                  d,
7187                                                                  false,
7188                                                                  -1 /* varlenarray */ ,
7189                                                                  -1 /* TEXT's typlen */ ,
7190                                                                  false /* TEXT's typbyval */ ,
7191                                                                  'i' /* TEXT's typalign */ );
7192                 }
7193                 else
7194                         newarray = construct_array(&d, 1,
7195                                                                            TEXTOID,
7196                                                                            -1, false, 'i');
7197
7198                 index++;
7199         }
7200
7201         return newarray;
7202 }
7203
7204
7205 /*
7206  * assign_hook and show_hook subroutines
7207  */
7208
7209 static const char *
7210 assign_log_destination(const char *value, bool doit, GucSource source)
7211 {
7212         char       *rawstring;
7213         List       *elemlist;
7214         ListCell   *l;
7215         int                     newlogdest = 0;
7216
7217         /* Need a modifiable copy of string */
7218         rawstring = pstrdup(value);
7219
7220         /* Parse string into list of identifiers */
7221         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7222         {
7223                 /* syntax error in list */
7224                 pfree(rawstring);
7225                 list_free(elemlist);
7226                 ereport(GUC_complaint_elevel(source),
7227                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7228                    errmsg("invalid list syntax for parameter \"log_destination\"")));
7229                 return NULL;
7230         }
7231
7232         foreach(l, elemlist)
7233         {
7234                 char       *tok = (char *) lfirst(l);
7235
7236                 if (pg_strcasecmp(tok, "stderr") == 0)
7237                         newlogdest |= LOG_DESTINATION_STDERR;
7238                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7239                         newlogdest |= LOG_DESTINATION_CSVLOG;
7240 #ifdef HAVE_SYSLOG
7241                 else if (pg_strcasecmp(tok, "syslog") == 0)
7242                         newlogdest |= LOG_DESTINATION_SYSLOG;
7243 #endif
7244 #ifdef WIN32
7245                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7246                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7247 #endif
7248                 else
7249                 {
7250                         ereport(GUC_complaint_elevel(source),
7251                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7252                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7253                                                  tok)));
7254                         pfree(rawstring);
7255                         list_free(elemlist);
7256                         return NULL;
7257                 }
7258         }
7259
7260         if (doit)
7261                 Log_destination = newlogdest;
7262
7263         pfree(rawstring);
7264         list_free(elemlist);
7265
7266         return value;
7267 }
7268
7269 #ifdef HAVE_SYSLOG
7270
7271 static bool
7272 assign_syslog_facility(int newval, bool doit, GucSource source)
7273 {
7274         if (doit)
7275                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7276                                                           newval);
7277
7278         return true;
7279 }
7280
7281 static const char *
7282 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7283 {
7284         if (doit)
7285                 set_syslog_parameters(ident, syslog_facility);
7286
7287         return ident;
7288 }
7289 #endif   /* HAVE_SYSLOG */
7290
7291
7292 static bool
7293 assign_session_replication_role(int newval, bool doit, GucSource source)
7294 {
7295         /*
7296          * Must flush the plan cache when changing replication role; but don't
7297          * flush unnecessarily.
7298          */
7299         if (doit && SessionReplicationRole != newval)
7300         {
7301                 ResetPlanCache();
7302         }
7303
7304         return true;
7305 }
7306
7307 static const char *
7308 show_num_temp_buffers(void)
7309 {
7310         /*
7311          * We show the GUC var until local buffers have been initialized, and
7312          * NLocBuffer afterwards.
7313          */
7314         static char nbuf[32];
7315
7316         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7317         return nbuf;
7318 }
7319
7320 static bool
7321 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7322 {
7323         if (!newval)
7324         {
7325                 ereport(GUC_complaint_elevel(source),
7326                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7327                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7328                 return false;
7329         }
7330         return true;
7331 }
7332
7333 static const char *
7334 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7335 {
7336         /*
7337          * Check syntax. newval must be a comma separated list of identifiers.
7338          * Whitespace is allowed but removed from the result.
7339          */
7340         bool            hasSpaceAfterToken = false;
7341         const char *cp = newval;
7342         int                     symLen = 0;
7343         char            c;
7344         StringInfoData buf;
7345
7346         initStringInfo(&buf);
7347         while ((c = *cp++) != '\0')
7348         {
7349                 if (isspace((unsigned char) c))
7350                 {
7351                         if (symLen > 0)
7352                                 hasSpaceAfterToken = true;
7353                         continue;
7354                 }
7355
7356                 if (c == ',')
7357                 {
7358                         if (symLen > 0)         /* terminate identifier */
7359                         {
7360                                 appendStringInfoChar(&buf, ',');
7361                                 symLen = 0;
7362                         }
7363                         hasSpaceAfterToken = false;
7364                         continue;
7365                 }
7366
7367                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7368                 {
7369                         /*
7370                          * Syntax error due to token following space after token or
7371                          * non-identifier character
7372                          */
7373                         pfree(buf.data);
7374                         return NULL;
7375                 }
7376                 appendStringInfoChar(&buf, c);
7377                 symLen++;
7378         }
7379
7380         /* Remove stray ',' at end */
7381         if (symLen == 0 && buf.len > 0)
7382                 buf.data[--buf.len] = '\0';
7383
7384         /* GUC wants the result malloc'd */
7385         newval = guc_strdup(LOG, buf.data);
7386
7387         pfree(buf.data);
7388         return newval;
7389 }
7390
7391 static bool
7392 assign_debug_assertions(bool newval, bool doit, GucSource source)
7393 {
7394 #ifndef USE_ASSERT_CHECKING
7395         if (newval)
7396         {
7397                 ereport(GUC_complaint_elevel(source),
7398                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7399                            errmsg("assertion checking is not supported by this build")));
7400                 return false;
7401         }
7402 #endif
7403         return true;
7404 }
7405
7406 static bool
7407 assign_bonjour(bool newval, bool doit, GucSource source)
7408 {
7409 #ifndef USE_BONJOUR
7410         if (newval)
7411         {
7412                 ereport(GUC_complaint_elevel(source),
7413                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7414                                  errmsg("Bonjour is not supported by this build")));
7415                 return false;
7416         }
7417 #endif
7418         return true;
7419 }
7420
7421 static bool
7422 assign_ssl(bool newval, bool doit, GucSource source)
7423 {
7424 #ifndef USE_SSL
7425         if (newval)
7426         {
7427                 ereport(GUC_complaint_elevel(source),
7428                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7429                                  errmsg("SSL is not supported by this build")));
7430                 return false;
7431         }
7432 #endif
7433         return true;
7434 }
7435
7436 static bool
7437 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7438 {
7439         if (newval && log_statement_stats)
7440         {
7441                 ereport(GUC_complaint_elevel(source),
7442                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7443                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7444                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7445                 if (source != PGC_S_OVERRIDE)
7446                         return false;
7447         }
7448         return true;
7449 }
7450
7451 static bool
7452 assign_log_stats(bool newval, bool doit, GucSource source)
7453 {
7454         if (newval &&
7455                 (log_parser_stats || log_planner_stats || log_executor_stats))
7456         {
7457                 ereport(GUC_complaint_elevel(source),
7458                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7459                                  errmsg("cannot enable \"log_statement_stats\" when "
7460                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7461                                                 "or \"log_executor_stats\" is true")));
7462                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7463                 if (source != PGC_S_OVERRIDE)
7464                         return false;
7465         }
7466         return true;
7467 }
7468
7469 static bool
7470 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7471 {
7472         /* Can't go to r/w mode inside a r/o transaction */
7473         if (newval == false && XactReadOnly && IsSubTransaction())
7474         {
7475                 ereport(GUC_complaint_elevel(source),
7476                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7477                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7478                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7479                 if (source != PGC_S_OVERRIDE)
7480                         return false;
7481         }
7482         return true;
7483 }
7484
7485 static const char *
7486 assign_canonical_path(const char *newval, bool doit, GucSource source)
7487 {
7488         if (doit)
7489         {
7490                 char       *canon_val = guc_strdup(ERROR, newval);
7491
7492                 canonicalize_path(canon_val);
7493                 return canon_val;
7494         }
7495         else
7496                 return newval;
7497 }
7498
7499 static const char *
7500 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7501 {
7502         /*
7503          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7504          * When we see this we just do nothing.  If this value isn't overridden
7505          * from the config file then pg_timezone_abbrev_initialize() will
7506          * eventually replace it with "Default".  This hack has two purposes: to
7507          * avoid wasting cycles loading values that might soon be overridden from
7508          * the config file, and to avoid trying to read the timezone abbrev files
7509          * during InitializeGUCOptions().  The latter doesn't work in an
7510          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7511          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7512          * delay initializing TimeZone ... if we have any more, we should try to
7513          * clean up and centralize this mechanism ...)
7514          */
7515         if (strcmp(newval, "UNKNOWN") == 0)
7516         {
7517                 return newval;
7518         }
7519
7520         /* Loading abbrev file is expensive, so only do it when value changes */
7521         if (timezone_abbreviations_string == NULL ||
7522                 strcmp(timezone_abbreviations_string, newval) != 0)
7523         {
7524                 int                     elevel;
7525
7526                 /*
7527                  * If reading config file, only the postmaster should bleat loudly
7528                  * about problems.      Otherwise, it's just this one process doing it,
7529                  * and we use WARNING message level.
7530                  */
7531                 if (source == PGC_S_FILE)
7532                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7533                 else
7534                         elevel = WARNING;
7535                 if (!load_tzoffsets(newval, doit, elevel))
7536                         return NULL;
7537         }
7538         return newval;
7539 }
7540
7541 /*
7542  * pg_timezone_abbrev_initialize --- set default value if not done already
7543  *
7544  * This is called after initial loading of postgresql.conf.  If no
7545  * timezone_abbreviations setting was found therein, select default.
7546  */
7547 void
7548 pg_timezone_abbrev_initialize(void)
7549 {
7550         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7551         {
7552                 SetConfigOption("timezone_abbreviations", "Default",
7553                                                 PGC_POSTMASTER, PGC_S_ARGV);
7554         }
7555 }
7556
7557 static const char *
7558 show_archive_command(void)
7559 {
7560         if (XLogArchiveMode)
7561                 return XLogArchiveCommand;
7562         else
7563                 return "(disabled)";
7564 }
7565
7566 static bool
7567 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7568 {
7569         if (doit)
7570                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7571
7572         return true;
7573 }
7574
7575 static const char *
7576 show_tcp_keepalives_idle(void)
7577 {
7578         static char nbuf[16];
7579
7580         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7581         return nbuf;
7582 }
7583
7584 static bool
7585 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7586 {
7587         if (doit)
7588                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7589
7590         return true;
7591 }
7592
7593 static const char *
7594 show_tcp_keepalives_interval(void)
7595 {
7596         static char nbuf[16];
7597
7598         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7599         return nbuf;
7600 }
7601
7602 static bool
7603 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7604 {
7605         if (doit)
7606                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7607
7608         return true;
7609 }
7610
7611 static const char *
7612 show_tcp_keepalives_count(void)
7613 {
7614         static char nbuf[16];
7615
7616         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7617         return nbuf;
7618 }
7619
7620 static bool
7621 assign_maxconnections(int newval, bool doit, GucSource source)
7622 {
7623         if (newval + autovacuum_max_workers + 1 > INT_MAX / 4)
7624                 return false;
7625
7626         if (doit)
7627                 MaxBackends = newval + autovacuum_max_workers + 1;
7628
7629         return true;
7630 }
7631
7632 static bool
7633 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7634 {
7635         if (MaxConnections + newval + 1 > INT_MAX / 4)
7636                 return false;
7637
7638         if (doit)
7639                 MaxBackends = MaxConnections + newval + 1;
7640
7641         return true;
7642 }
7643
7644 static bool
7645 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7646 {
7647 #ifdef USE_PREFETCH
7648         double          new_prefetch_pages = 0.0;
7649         int                     i;
7650
7651         /*----------
7652          * The user-visible GUC parameter is the number of drives (spindles),
7653          * which we need to translate to a number-of-pages-to-prefetch target.
7654          *
7655          * The expected number of prefetch pages needed to keep N drives busy is:
7656          *
7657          * drives |   I/O requests
7658          * -------+----------------
7659          *              1 |   1
7660          *              2 |   2/1 + 2/2 = 3
7661          *              3 |   3/1 + 3/2 + 3/3 = 5 1/2
7662          *              4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7663          *              n |   n * H(n)
7664          *
7665          * This is called the "coupon collector problem" and H(n) is called the
7666          * harmonic series.  This could be approximated by n * ln(n), but for
7667          * reasonable numbers of drives we might as well just compute the series.
7668          *
7669          * Alternatively we could set the target to the number of pages necessary
7670          * so that the expected number of active spindles is some arbitrary
7671          * percentage of the total.  This sounds the same but is actually slightly
7672          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7673          * that desired fraction.
7674          *
7675          * Experimental results show that both of these formulas aren't aggressive
7676          * enough, but we don't really have any better proposals.
7677          *
7678          * Note that if newval = 0 (disabled), we must set target = 0.
7679          *----------
7680          */
7681
7682         for (i = 1; i <= newval; i++)
7683                 new_prefetch_pages += (double) newval / (double) i;
7684
7685         /* This range check shouldn't fail, but let's be paranoid */
7686         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7687         {
7688                 if (doit)
7689                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7690                 return true;
7691         }
7692         else
7693                 return false;
7694 #else
7695         return true;
7696 #endif   /* USE_PREFETCH */
7697 }
7698
7699 static const char *
7700 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7701 {
7702         if (doit)
7703         {
7704                 char       *canon_val = guc_strdup(ERROR, newval);
7705                 char       *tname;
7706                 char       *fname;
7707
7708                 canonicalize_path(canon_val);
7709
7710                 tname = guc_malloc(ERROR, strlen(canon_val) + 12);              /* /pgstat.tmp */
7711                 sprintf(tname, "%s/pgstat.tmp", canon_val);
7712                 fname = guc_malloc(ERROR, strlen(canon_val) + 13);              /* /pgstat.stat */
7713                 sprintf(fname, "%s/pgstat.stat", canon_val);
7714
7715                 if (pgstat_stat_tmpname)
7716                         free(pgstat_stat_tmpname);
7717                 pgstat_stat_tmpname = tname;
7718                 if (pgstat_stat_filename)
7719                         free(pgstat_stat_filename);
7720                 pgstat_stat_filename = fname;
7721
7722                 return canon_val;
7723         }
7724         else
7725                 return newval;
7726 }
7727
7728 #include "guc-file.c"