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 1.512 2009/08/29 19:26:51 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_ssl(bool newval, bool doit, GucSource source);
 156 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 157 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 158 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 159 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 160 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 161 static const char *show_archive_command(void);
 162 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 163 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 164 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 165 static const char *show_tcp_keepalives_idle(void);
 166 static const char *show_tcp_keepalives_interval(void);
 167 static const char *show_tcp_keepalives_count(void);
 168 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 169 static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource source);
 170 static bool assign_effective_io_concurrency(int newval, bool doit, GucSource source);
 171 static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
 172
 173 static char *config_enum_get_options(struct config_enum * record,
 174                                                 const char *prefix, const char *suffix,
 175                                                 const char *separator);
 176
 177
 178 /*
 179  * Options for enum values defined in this module.
 180  *
 181  * NOTE! Option values may not contain double quotes!
 182  */
 183
 184 static const struct config_enum_entry bytea_output_options[] = {
 185         {"escape", BYTEA_OUTPUT_ESCAPE, false},
 186         {"hex", BYTEA_OUTPUT_HEX, false},
 187         {NULL, 0, false}
 188 };
 189
 190 /*
 191  * We have different sets for client and server message level options because
 192  * they sort slightly different (see "log" level)
 193  */
 194 static const struct config_enum_entry client_message_level_options[] = {
 195         {"debug", DEBUG2, true},
 196         {"debug5", DEBUG5, false},
 197         {"debug4", DEBUG4, false},
 198         {"debug3", DEBUG3, false},
 199         {"debug2", DEBUG2, false},
 200         {"debug1", DEBUG1, false},
 201         {"log", LOG, false},
 202         {"info", INFO, true},
 203         {"notice", NOTICE, false},
 204         {"warning", WARNING, false},
 205         {"error", ERROR, false},
 206         {"fatal", FATAL, true},
 207         {"panic", PANIC, true},
 208         {NULL, 0, false}
 209 };
 210
 211 static const struct config_enum_entry server_message_level_options[] = {
 212         {"debug", DEBUG2, true},
 213         {"debug5", DEBUG5, false},
 214         {"debug4", DEBUG4, false},
 215         {"debug3", DEBUG3, false},
 216         {"debug2", DEBUG2, false},
 217         {"debug1", DEBUG1, false},
 218         {"info", INFO, false},
 219         {"notice", NOTICE, false},
 220         {"warning", WARNING, false},
 221         {"error", ERROR, false},
 222         {"log", LOG, false},
 223         {"fatal", FATAL, false},
 224         {"panic", PANIC, false},
 225         {NULL, 0, false}
 226 };
 227
 228 static const struct config_enum_entry intervalstyle_options[] = {
 229         {"postgres", INTSTYLE_POSTGRES, false},
 230         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 231         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 232         {"iso_8601", INTSTYLE_ISO_8601, false},
 233         {NULL, 0, false}
 234 };
 235
 236 static const struct config_enum_entry log_error_verbosity_options[] = {
 237         {"terse", PGERROR_TERSE, false},
 238         {"default", PGERROR_DEFAULT, false},
 239         {"verbose", PGERROR_VERBOSE, false},
 240         {NULL, 0, false}
 241 };
 242
 243 static const struct config_enum_entry log_statement_options[] = {
 244         {"none", LOGSTMT_NONE, false},
 245         {"ddl", LOGSTMT_DDL, false},
 246         {"mod", LOGSTMT_MOD, false},
 247         {"all", LOGSTMT_ALL, false},
 248         {NULL, 0, false}
 249 };
 250
 251 static const struct config_enum_entry regex_flavor_options[] = {
 252         {"advanced", REG_ADVANCED, false},
 253         {"extended", REG_EXTENDED, false},
 254         {"basic", REG_BASIC, false},
 255         {NULL, 0, false}
 256 };
 257
 258 static const struct config_enum_entry isolation_level_options[] = {
 259         {"serializable", XACT_SERIALIZABLE, false},
 260         {"repeatable read", XACT_REPEATABLE_READ, false},
 261         {"read committed", XACT_READ_COMMITTED, false},
 262         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 263         {NULL, 0}
 264 };
 265
 266 static const struct config_enum_entry session_replication_role_options[] = {
 267         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 268         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 269         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 270         {NULL, 0, false}
 271 };
 272
 273 #ifdef HAVE_SYSLOG
 274 static const struct config_enum_entry syslog_facility_options[] = {
 275         {"local0", LOG_LOCAL0, false},
 276         {"local1", LOG_LOCAL1, false},
 277         {"local2", LOG_LOCAL2, false},
 278         {"local3", LOG_LOCAL3, false},
 279         {"local4", LOG_LOCAL4, false},
 280         {"local5", LOG_LOCAL5, false},
 281         {"local6", LOG_LOCAL6, false},
 282         {"local7", LOG_LOCAL7, false},
 283         {NULL, 0}
 284 };
 285 #endif
 286
 287 static const struct config_enum_entry track_function_options[] = {
 288         {"none", TRACK_FUNC_OFF, false},
 289         {"pl", TRACK_FUNC_PL, false},
 290         {"all", TRACK_FUNC_ALL, false},
 291         {NULL, 0, false}
 292 };
 293
 294 static const struct config_enum_entry xmlbinary_options[] = {
 295         {"base64", XMLBINARY_BASE64, false},
 296         {"hex", XMLBINARY_HEX, false},
 297         {NULL, 0, false}
 298 };
 299
 300 static const struct config_enum_entry xmloption_options[] = {
 301         {"content", XMLOPTION_CONTENT, false},
 302         {"document", XMLOPTION_DOCUMENT, false},
 303         {NULL, 0, false}
 304 };
 305
 306 /*
 307  * Although only "on", "off", and "safe_encoding" are documented, we
 308  * accept all the likely variants of "on" and "off".
 309  */
 310 static const struct config_enum_entry backslash_quote_options[] = {
 311         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 312         {"on", BACKSLASH_QUOTE_ON, false},
 313         {"off", BACKSLASH_QUOTE_OFF, false},
 314         {"true", BACKSLASH_QUOTE_ON, true},
 315         {"false", BACKSLASH_QUOTE_OFF, true},
 316         {"yes", BACKSLASH_QUOTE_ON, true},
 317         {"no", BACKSLASH_QUOTE_OFF, true},
 318         {"1", BACKSLASH_QUOTE_ON, true},
 319         {"0", BACKSLASH_QUOTE_OFF, true},
 320         {NULL, 0, false}
 321 };
 322
 323 /*
 324  * Although only "on", "off", and "partition" are documented, we
 325  * accept all the likely variants of "on" and "off".
 326  */
 327 static const struct config_enum_entry constraint_exclusion_options[] = {
 328         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 329         {"on", CONSTRAINT_EXCLUSION_ON, false},
 330         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 331         {"true", CONSTRAINT_EXCLUSION_ON, true},
 332         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 333         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 334         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 335         {"1", CONSTRAINT_EXCLUSION_ON, true},
 336         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 337         {NULL, 0, false}
 338 };
 339
 340 /*
 341  * Options for enum values stored in other modules
 342  */
 343 extern const struct config_enum_entry sync_method_options[];
 344
 345 /*
 346  * GUC option variables that are exported from this module
 347  */
 348 #ifdef USE_ASSERT_CHECKING
 349 bool            assert_enabled = true;
 350 #else
 351 bool            assert_enabled = false;
 352 #endif
 353 bool            log_duration = false;
 354 bool            Debug_print_plan = false;
 355 bool            Debug_print_parse = false;
 356 bool            Debug_print_rewritten = false;
 357 bool            Debug_pretty_print = true;
 358
 359 bool            log_parser_stats = false;
 360 bool            log_planner_stats = false;
 361 bool            log_executor_stats = false;
 362 bool            log_statement_stats = false;            /* this is sort of all three
 363                                                                                                  * above together */
 364 bool            log_btree_build_stats = false;
 365
 366 bool            check_function_bodies = true;
 367 bool            default_with_oids = false;
 368 bool            SQL_inheritance = true;
 369
 370 bool            Password_encryption = true;
 371
 372 int                     log_min_error_statement = ERROR;
 373 int                     log_min_messages = WARNING;
 374 int                     client_min_messages = NOTICE;
 375 int                     log_min_duration_statement = -1;
 376 int                     log_temp_files = -1;
 377
 378 int                     num_temp_buffers = 1000;
 379
 380 char       *ConfigFileName;
 381 char       *HbaFileName;
 382 char       *IdentFileName;
 383 char       *external_pid_file;
 384
 385 char       *pgstat_temp_directory;
 386
 387 int                     tcp_keepalives_idle;
 388 int                     tcp_keepalives_interval;
 389 int                     tcp_keepalives_count;
 390
 391 /*
 392  * These variables are all dummies that don't do anything, except in some
 393  * cases provide the value for SHOW to display.  The real state is elsewhere
 394  * and is kept in sync by assign_hooks.
 395  */
 396 static char *log_destination_string;
 397
 398 #ifdef HAVE_SYSLOG
 399 static char *syslog_ident_str;
 400 #endif
 401 static bool phony_autocommit;
 402 static bool session_auth_is_superuser;
 403 static double phony_random_seed;
 404 static char *client_encoding_string;
 405 static char *datestyle_string;
 406 static char *locale_collate;
 407 static char *locale_ctype;
 408 static char *server_encoding_string;
 409 static char *server_version_string;
 410 static int      server_version_num;
 411 static char *timezone_string;
 412 static char *log_timezone_string;
 413 static char *timezone_abbreviations_string;
 414 static char *XactIsoLevel_string;
 415 static char *data_directory;
 416 static char *custom_variable_classes;
 417 static int      max_function_args;
 418 static int      max_index_keys;
 419 static int      max_identifier_length;
 420 static int      block_size;
 421 static int      segment_size;
 422 static int      wal_block_size;
 423 static int      wal_segment_size;
 424 static bool integer_datetimes;
 425 static int      effective_io_concurrency;
 426
 427 /* should be static, but commands/variable.c needs to get at these */
 428 char       *role_string;
 429 char       *session_authorization_string;
 430
 431
 432 /*
 433  * Displayable names for context types (enum GucContext)
 434  *
 435  * Note: these strings are deliberately not localized.
 436  */
 437 const char *const GucContext_Names[] =
 438 {
 439          /* PGC_INTERNAL */ "internal",
 440          /* PGC_POSTMASTER */ "postmaster",
 441          /* PGC_SIGHUP */ "sighup",
 442          /* PGC_BACKEND */ "backend",
 443          /* PGC_SUSET */ "superuser",
 444          /* PGC_USERSET */ "user"
 445 };
 446
 447 /*
 448  * Displayable names for source types (enum GucSource)
 449  *
 450  * Note: these strings are deliberately not localized.
 451  */
 452 const char *const GucSource_Names[] =
 453 {
 454          /* PGC_S_DEFAULT */ "default",
 455          /* PGC_S_ENV_VAR */ "environment variable",
 456          /* PGC_S_FILE */ "configuration file",
 457          /* PGC_S_ARGV */ "command line",
 458          /* PGC_S_DATABASE */ "database",
 459          /* PGC_S_USER */ "user",
 460          /* PGC_S_CLIENT */ "client",
 461          /* PGC_S_OVERRIDE */ "override",
 462          /* PGC_S_INTERACTIVE */ "interactive",
 463          /* PGC_S_TEST */ "test",
 464          /* PGC_S_SESSION */ "session"
 465 };
 466
 467 /*
 468  * Displayable names for the groupings defined in enum config_group
 469  */
 470 const char *const config_group_names[] =
 471 {
 472         /* UNGROUPED */
 473         gettext_noop("Ungrouped"),
 474         /* FILE_LOCATIONS */
 475         gettext_noop("File Locations"),
 476         /* CONN_AUTH */
 477         gettext_noop("Connections and Authentication"),
 478         /* CONN_AUTH_SETTINGS */
 479         gettext_noop("Connections and Authentication / Connection Settings"),
 480         /* CONN_AUTH_SECURITY */
 481         gettext_noop("Connections and Authentication / Security and Authentication"),
 482         /* RESOURCES */
 483         gettext_noop("Resource Usage"),
 484         /* RESOURCES_MEM */
 485         gettext_noop("Resource Usage / Memory"),
 486         /* RESOURCES_KERNEL */
 487         gettext_noop("Resource Usage / Kernel Resources"),
 488         /* WAL */
 489         gettext_noop("Write-Ahead Log"),
 490         /* WAL_SETTINGS */
 491         gettext_noop("Write-Ahead Log / Settings"),
 492         /* WAL_CHECKPOINTS */
 493         gettext_noop("Write-Ahead Log / Checkpoints"),
 494         /* QUERY_TUNING */
 495         gettext_noop("Query Tuning"),
 496         /* QUERY_TUNING_METHOD */
 497         gettext_noop("Query Tuning / Planner Method Configuration"),
 498         /* QUERY_TUNING_COST */
 499         gettext_noop("Query Tuning / Planner Cost Constants"),
 500         /* QUERY_TUNING_GEQO */
 501         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 502         /* QUERY_TUNING_OTHER */
 503         gettext_noop("Query Tuning / Other Planner Options"),
 504         /* LOGGING */
 505         gettext_noop("Reporting and Logging"),
 506         /* LOGGING_WHERE */
 507         gettext_noop("Reporting and Logging / Where to Log"),
 508         /* LOGGING_WHEN */
 509         gettext_noop("Reporting and Logging / When to Log"),
 510         /* LOGGING_WHAT */
 511         gettext_noop("Reporting and Logging / What to Log"),
 512         /* STATS */
 513         gettext_noop("Statistics"),
 514         /* STATS_MONITORING */
 515         gettext_noop("Statistics / Monitoring"),
 516         /* STATS_COLLECTOR */
 517         gettext_noop("Statistics / Query and Index Statistics Collector"),
 518         /* AUTOVACUUM */
 519         gettext_noop("Autovacuum"),
 520         /* CLIENT_CONN */
 521         gettext_noop("Client Connection Defaults"),
 522         /* CLIENT_CONN_STATEMENT */
 523         gettext_noop("Client Connection Defaults / Statement Behavior"),
 524         /* CLIENT_CONN_LOCALE */
 525         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 526         /* CLIENT_CONN_OTHER */
 527         gettext_noop("Client Connection Defaults / Other Defaults"),
 528         /* LOCK_MANAGEMENT */
 529         gettext_noop("Lock Management"),
 530         /* COMPAT_OPTIONS */
 531         gettext_noop("Version and Platform Compatibility"),
 532         /* COMPAT_OPTIONS_PREVIOUS */
 533         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 534         /* COMPAT_OPTIONS_CLIENT */
 535         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 536         /* PRESET_OPTIONS */
 537         gettext_noop("Preset Options"),
 538         /* CUSTOM_OPTIONS */
 539         gettext_noop("Customized Options"),
 540         /* DEVELOPER_OPTIONS */
 541         gettext_noop("Developer Options"),
 542         /* help_config wants this array to be null-terminated */
 543         NULL
 544 };
 545
 546 /*
 547  * Displayable names for GUC variable types (enum config_type)
 548  *
 549  * Note: these strings are deliberately not localized.
 550  */
 551 const char *const config_type_names[] =
 552 {
 553          /* PGC_BOOL */ "bool",
 554          /* PGC_INT */ "integer",
 555          /* PGC_REAL */ "real",
 556          /* PGC_STRING */ "string",
 557          /* PGC_ENUM */ "enum"
 558 };
 559
 560
 561 /*
 562  * Contents of GUC tables
 563  *
 564  * See src/backend/utils/misc/README for design notes.
 565  *
 566  * TO ADD AN OPTION:
 567  *
 568  * 1. Declare a global variable of type bool, int, double, or char*
 569  *        and make use of it.
 570  *
 571  * 2. Decide at what times it's safe to set the option. See guc.h for
 572  *        details.
 573  *
 574  * 3. Decide on a name, a default value, upper and lower bounds (if
 575  *        applicable), etc.
 576  *
 577  * 4. Add a record below.
 578  *
 579  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 580  *        appropriate.
 581  *
 582  * 6. Don't forget to document the option (at least in config.sgml).
 583  *
 584  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 585  *        it is not single quoted at dump time.
 586  */
 587
 588
 589 /******** option records follow ********/
 590
 591 static struct config_bool ConfigureNamesBool[] =
 592 {
 593         {
 594                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 595                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 596                         NULL
 597                 },
 598                 &enable_seqscan,
 599                 true, NULL, NULL
 600         },
 601         {
 602                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 603                         gettext_noop("Enables the planner's use of index-scan plans."),
 604                         NULL
 605                 },
 606                 &enable_indexscan,
 607                 true, NULL, NULL
 608         },
 609         {
 610                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 611                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 612                         NULL
 613                 },
 614                 &enable_bitmapscan,
 615                 true, NULL, NULL
 616         },
 617         {
 618                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 619                         gettext_noop("Enables the planner's use of TID scan plans."),
 620                         NULL
 621                 },
 622                 &enable_tidscan,
 623                 true, NULL, NULL
 624         },
 625         {
 626                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 627                         gettext_noop("Enables the planner's use of explicit sort steps."),
 628                         NULL
 629                 },
 630                 &enable_sort,
 631                 true, NULL, NULL
 632         },
 633         {
 634                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 635                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 636                         NULL
 637                 },
 638                 &enable_hashagg,
 639                 true, NULL, NULL
 640         },
 641         {
 642                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 643                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 644                         NULL
 645                 },
 646                 &enable_nestloop,
 647                 true, NULL, NULL
 648         },
 649         {
 650                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 651                         gettext_noop("Enables the planner's use of merge join plans."),
 652                         NULL
 653                 },
 654                 &enable_mergejoin,
 655                 true, NULL, NULL
 656         },
 657         {
 658                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 659                         gettext_noop("Enables the planner's use of hash join plans."),
 660                         NULL
 661                 },
 662                 &enable_hashjoin,
 663                 true, NULL, NULL
 664         },
 665         {
 666                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 667                         gettext_noop("Enables genetic query optimization."),
 668                         gettext_noop("This algorithm attempts to do planning without "
 669                                                  "exhaustive searching.")
 670                 },
 671                 &enable_geqo,
 672                 true, NULL, NULL
 673         },
 674         {
 675                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 676                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 677                         gettext_noop("Shows whether the current user is a superuser."),
 678                         NULL,
 679                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 680                 },
 681                 &session_auth_is_superuser,
 682                 false, NULL, NULL
 683         },
 684         {
 685                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 686                         gettext_noop("Enables SSL connections."),
 687                         NULL
 688                 },
 689                 &EnableSSL,
 690                 false, assign_ssl, NULL
 691         },
 692         {
 693                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 694                         gettext_noop("Forces synchronization of updates to disk."),
 695                         gettext_noop("The server will use the fsync() system call in several places to make "
 696                         "sure that updates are physically written to disk. This insures "
 697                                                  "that a database cluster will recover to a consistent state after "
 698                                                  "an operating system or hardware crash.")
 699                 },
 700                 &enableFsync,
 701                 true, NULL, NULL
 702         },
 703         {
 704                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 705                         gettext_noop("Sets immediate fsync at commit."),
 706                         NULL
 707                 },
 708                 &XactSyncCommit,
 709                 true, NULL, NULL
 710         },
 711         {
 712                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 713                         gettext_noop("Continues processing past damaged page headers."),
 714                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 715                                 "report an error, aborting the current transaction. Setting "
 716                                                  "zero_damaged_pages to true causes the system to instead report a "
 717                                                  "warning, zero out the damaged page, and continue processing. This "
 718                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 719                         GUC_NOT_IN_SAMPLE
 720                 },
 721                 &zero_damaged_pages,
 722                 false, NULL, NULL
 723         },
 724         {
 725                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 726                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 727                         gettext_noop("A page write in process during an operating system crash might be "
 728                                                  "only partially written to disk.  During recovery, the row changes "
 729                           "stored in WAL are not enough to recover.  This option writes "
 730                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 731                                                  "is possible.")
 732                 },
 733                 &fullPageWrites,
 734                 true, NULL, NULL
 735         },
 736         {
 737                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHERE,
 738                         gettext_noop("Runs the server silently."),
 739                         gettext_noop("If this parameter is set, the server will automatically run in the "
 740                                  "background and any controlling terminals are dissociated.")
 741                 },
 742                 &SilentMode,
 743                 false, NULL, NULL
 744         },
 745         {
 746                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 747                         gettext_noop("Logs each checkpoint."),
 748                         NULL
 749                 },
 750                 &log_checkpoints,
 751                 false, NULL, NULL
 752         },
 753         {
 754                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 755                         gettext_noop("Logs each successful connection."),
 756                         NULL
 757                 },
 758                 &Log_connections,
 759                 false, NULL, NULL
 760         },
 761         {
 762                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 763                         gettext_noop("Logs end of a session, including duration."),
 764                         NULL
 765                 },
 766                 &Log_disconnections,
 767                 false, NULL, NULL
 768         },
 769         {
 770                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 771                         gettext_noop("Turns on various assertion checks."),
 772                         gettext_noop("This is a debugging aid."),
 773                         GUC_NOT_IN_SAMPLE
 774                 },
 775                 &assert_enabled,
 776 #ifdef USE_ASSERT_CHECKING
 777                 true,
 778 #else
 779                 false,
 780 #endif
 781                 assign_debug_assertions, NULL
 782         },
 783         {
 784                 /* currently undocumented, so don't show in SHOW ALL */
 785                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 786                         gettext_noop("No description available."),
 787                         NULL,
 788                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 789                 },
 790                 &ExitOnAnyError,
 791                 false, NULL, NULL
 792         },
 793         {
 794                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 795                         gettext_noop("Logs the duration of each completed SQL statement."),
 796                         NULL
 797                 },
 798                 &log_duration,
 799                 false, NULL, NULL
 800         },
 801         {
 802                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 803                         gettext_noop("Logs each query's parse tree."),
 804                         NULL
 805                 },
 806                 &Debug_print_parse,
 807                 false, NULL, NULL
 808         },
 809         {
 810                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 811                         gettext_noop("Logs each query's rewritten parse tree."),
 812                         NULL
 813                 },
 814                 &Debug_print_rewritten,
 815                 false, NULL, NULL
 816         },
 817         {
 818                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 819                         gettext_noop("Logs each query's execution plan."),
 820                         NULL
 821                 },
 822                 &Debug_print_plan,
 823                 false, NULL, NULL
 824         },
 825         {
 826                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 827                         gettext_noop("Indents parse and plan tree displays."),
 828                         NULL
 829                 },
 830                 &Debug_pretty_print,
 831                 true, NULL, NULL
 832         },
 833         {
 834                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 835                         gettext_noop("Writes parser performance statistics to the server log."),
 836                         NULL
 837                 },
 838                 &log_parser_stats,
 839                 false, assign_stage_log_stats, NULL
 840         },
 841         {
 842                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 843                         gettext_noop("Writes planner performance statistics to the server log."),
 844                         NULL
 845                 },
 846                 &log_planner_stats,
 847                 false, assign_stage_log_stats, NULL
 848         },
 849         {
 850                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 851                         gettext_noop("Writes executor performance statistics to the server log."),
 852                         NULL
 853                 },
 854                 &log_executor_stats,
 855                 false, assign_stage_log_stats, NULL
 856         },
 857         {
 858                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 859                         gettext_noop("Writes cumulative performance statistics to the server log."),
 860                         NULL
 861                 },
 862                 &log_statement_stats,
 863                 false, assign_log_stats, NULL
 864         },
 865 #ifdef BTREE_BUILD_STATS
 866         {
 867                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 868                         gettext_noop("No description available."),
 869                         NULL,
 870                         GUC_NOT_IN_SAMPLE
 871                 },
 872                 &log_btree_build_stats,
 873                 false, NULL, NULL
 874         },
 875 #endif
 876
 877         {
 878                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 879                         gettext_noop("Collects information about executing commands."),
 880                         gettext_noop("Enables the collection of information on the currently "
 881                                                  "executing command of each session, along with "
 882                                                  "the time at which that command began execution.")
 883                 },
 884                 &pgstat_track_activities,
 885                 true, NULL, NULL
 886         },
 887         {
 888                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 889                         gettext_noop("Collects statistics on database activity."),
 890                         NULL
 891                 },
 892                 &pgstat_track_counts,
 893                 true, NULL, NULL
 894         },
 895
 896         {
 897                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 898                         gettext_noop("Updates the process title to show the active SQL command."),
 899                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 900                 },
 901                 &update_process_title,
 902                 true, NULL, NULL
 903         },
 904
 905         {
 906                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 907                         gettext_noop("Starts the autovacuum subprocess."),
 908                         NULL
 909                 },
 910                 &autovacuum_start_daemon,
 911                 true, NULL, NULL
 912         },
 913
 914         {
 915                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 916                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 917                         NULL,
 918                         GUC_NOT_IN_SAMPLE
 919                 },
 920                 &Trace_notify,
 921                 false, NULL, NULL
 922         },
 923
 924 #ifdef LOCK_DEBUG
 925         {
 926                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 927                         gettext_noop("No description available."),
 928                         NULL,
 929                         GUC_NOT_IN_SAMPLE
 930                 },
 931                 &Trace_locks,
 932                 false, NULL, NULL
 933         },
 934         {
 935                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 936                         gettext_noop("No description available."),
 937                         NULL,
 938                         GUC_NOT_IN_SAMPLE
 939                 },
 940                 &Trace_userlocks,
 941                 false, NULL, NULL
 942         },
 943         {
 944                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 945                         gettext_noop("No description available."),
 946                         NULL,
 947                         GUC_NOT_IN_SAMPLE
 948                 },
 949                 &Trace_lwlocks,
 950                 false, NULL, NULL
 951         },
 952         {
 953                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 954                         gettext_noop("No description available."),
 955                         NULL,
 956                         GUC_NOT_IN_SAMPLE
 957                 },
 958                 &Debug_deadlocks,
 959                 false, NULL, NULL
 960         },
 961 #endif
 962
 963         {
 964                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 965                         gettext_noop("Logs long lock waits."),
 966                         NULL
 967                 },
 968                 &log_lock_waits,
 969                 false, NULL, NULL
 970         },
 971
 972         {
 973                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 974                         gettext_noop("Logs the host name in the connection logs."),
 975                         gettext_noop("By default, connection logs only show the IP address "
 976                                                  "of the connecting host. If you want them to show the host name you "
 977                           "can turn this on, but depending on your host name resolution "
 978                            "setup it might impose a non-negligible performance penalty.")
 979                 },
 980                 &log_hostname,
 981                 false, NULL, NULL
 982         },
 983         {
 984                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 985                         gettext_noop("Causes subtables to be included by default in various commands."),
 986                         NULL
 987                 },
 988                 &SQL_inheritance,
 989                 true, NULL, NULL
 990         },
 991         {
 992                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 993                         gettext_noop("Encrypt passwords."),
 994                         gettext_noop("When a password is specified in CREATE USER or "
 995                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 996                                                  "this parameter determines whether the password is to be encrypted.")
 997                 },
 998                 &Password_encryption,
 999                 true, NULL, NULL
1000         },
1001         {
1002                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
1003                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
1004                         gettext_noop("When turned on, expressions of the form expr = NULL "
1005                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
1006                                 "return true if expr evaluates to the null value, and false "
1007                            "otherwise. The correct behavior of expr = NULL is to always "
1008                                                  "return null (unknown).")
1009                 },
1010                 &Transform_null_equals,
1011                 false, NULL, NULL
1012         },
1013         {
1014                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1015                         gettext_noop("Enables per-database user names."),
1016                         NULL
1017                 },
1018                 &Db_user_namespace,
1019                 false, NULL, NULL
1020         },
1021         {
1022                 /* only here for backwards compatibility */
1023                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1024                         gettext_noop("This parameter doesn't do anything."),
1025                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1026                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1027                 },
1028                 &phony_autocommit,
1029                 true, assign_phony_autocommit, NULL
1030         },
1031         {
1032                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1033                         gettext_noop("Sets the default read-only status of new transactions."),
1034                         NULL
1035                 },
1036                 &DefaultXactReadOnly,
1037                 false, NULL, NULL
1038         },
1039         {
1040                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1041                         gettext_noop("Sets the current transaction's read-only status."),
1042                         NULL,
1043                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1044                 },
1045                 &XactReadOnly,
1046                 false, assign_transaction_read_only, NULL
1047         },
1048         {
1049                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1050                         gettext_noop("Automatically adds missing table references to FROM clauses."),
1051                         NULL
1052                 },
1053                 &add_missing_from,
1054                 false, NULL, NULL
1055         },
1056         {
1057                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1058                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1059                         NULL
1060                 },
1061                 &check_function_bodies,
1062                 true, NULL, NULL
1063         },
1064         {
1065                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1066                         gettext_noop("Enable input of NULL elements in arrays."),
1067                         gettext_noop("When turned on, unquoted NULL in an array input "
1068                                                  "value means a null value; "
1069                                                  "otherwise it is taken literally.")
1070                 },
1071                 &Array_nulls,
1072                 true, NULL, NULL
1073         },
1074         {
1075                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1076                         gettext_noop("Create new tables with OIDs by default."),
1077                         NULL
1078                 },
1079                 &default_with_oids,
1080                 false, NULL, NULL
1081         },
1082         {
1083                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1084                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1085                         NULL
1086                 },
1087                 &Logging_collector,
1088                 false, NULL, NULL
1089         },
1090         {
1091                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1092                         gettext_noop("Truncate existing log files of same name during log rotation."),
1093                         NULL
1094                 },
1095                 &Log_truncate_on_rotation,
1096                 false, NULL, NULL
1097         },
1098
1099 #ifdef TRACE_SORT
1100         {
1101                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1102                         gettext_noop("Emit information about resource usage in sorting."),
1103                         NULL,
1104                         GUC_NOT_IN_SAMPLE
1105                 },
1106                 &trace_sort,
1107                 false, NULL, NULL
1108         },
1109 #endif
1110
1111 #ifdef TRACE_SYNCSCAN
1112         /* this is undocumented because not exposed in a standard build */
1113         {
1114                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1115                         gettext_noop("Generate debugging output for synchronized scanning."),
1116                         NULL,
1117                         GUC_NOT_IN_SAMPLE
1118                 },
1119                 &trace_syncscan,
1120                 false, NULL, NULL
1121         },
1122 #endif
1123
1124 #ifdef DEBUG_BOUNDED_SORT
1125         /* this is undocumented because not exposed in a standard build */
1126         {
1127                 {
1128                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1129                         gettext_noop("Enable bounded sorting using heap sort."),
1130                         NULL,
1131                         GUC_NOT_IN_SAMPLE
1132                 },
1133                 &optimize_bounded_sort,
1134                 true, NULL, NULL
1135         },
1136 #endif
1137
1138 #ifdef WAL_DEBUG
1139         {
1140                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1141                         gettext_noop("Emit WAL-related debugging output."),
1142                         NULL,
1143                         GUC_NOT_IN_SAMPLE
1144                 },
1145                 &XLOG_DEBUG,
1146                 false, NULL, NULL
1147         },
1148 #endif
1149
1150         {
1151                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1152                         gettext_noop("Datetimes are integer based."),
1153                         NULL,
1154                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1155                 },
1156                 &integer_datetimes,
1157 #ifdef HAVE_INT64_TIMESTAMP
1158                 true, NULL, NULL
1159 #else
1160                 false, NULL, NULL
1161 #endif
1162         },
1163
1164         {
1165                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1166                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1167                         NULL
1168                 },
1169                 &pg_krb_caseins_users,
1170                 false, NULL, NULL
1171         },
1172
1173         {
1174                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1175                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1176                         NULL
1177                 },
1178                 &escape_string_warning,
1179                 true, NULL, NULL
1180         },
1181
1182         {
1183                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1184                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1185                         NULL,
1186                         GUC_REPORT
1187                 },
1188                 &standard_conforming_strings,
1189                 false, NULL, NULL
1190         },
1191
1192         {
1193                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1194                         gettext_noop("Enable synchronized sequential scans."),
1195                         NULL
1196                 },
1197                 &synchronize_seqscans,
1198                 true, NULL, NULL
1199         },
1200
1201         {
1202                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1203                         gettext_noop("Allows archiving of WAL files using archive_command."),
1204                         NULL
1205                 },
1206                 &XLogArchiveMode,
1207                 false, NULL, NULL
1208         },
1209
1210         {
1211                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1212                         gettext_noop("Allows modifications of the structure of system tables."),
1213                         NULL,
1214                         GUC_NOT_IN_SAMPLE
1215                 },
1216                 &allowSystemTableMods,
1217                 false, NULL, NULL
1218         },
1219
1220         {
1221                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1222                         gettext_noop("Disables reading from system indexes."),
1223                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1224                                                  "to use.  The worst consequence is slowness."),
1225                         GUC_NOT_IN_SAMPLE
1226                 },
1227                 &IgnoreSystemIndexes,
1228                 false, NULL, NULL
1229         },
1230
1231         /* End-of-list marker */
1232         {
1233                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1234         }
1235 };
1236
1237
1238 static struct config_int ConfigureNamesInt[] =
1239 {
1240         {
1241                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1242                         gettext_noop("Forces a switch to the next xlog file if a "
1243                                                  "new file has not been started within N seconds."),
1244                         NULL,
1245                         GUC_UNIT_S
1246                 },
1247                 &XLogArchiveTimeout,
1248                 0, 0, INT_MAX, NULL, NULL
1249         },
1250         {
1251                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1252                         gettext_noop("Waits N seconds on connection startup after authentication."),
1253                         gettext_noop("This allows attaching a debugger to the process."),
1254                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1255                 },
1256                 &PostAuthDelay,
1257                 0, 0, INT_MAX, NULL, NULL
1258         },
1259         {
1260                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1261                         gettext_noop("Sets the default statistics target."),
1262                         gettext_noop("This applies to table columns that have not had a "
1263                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1264                 },
1265                 &default_statistics_target,
1266                 100, 1, 10000, NULL, NULL
1267         },
1268         {
1269                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1270                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1271                                                  "are not collapsed."),
1272                         gettext_noop("The planner will merge subqueries into upper "
1273                                 "queries if the resulting FROM list would have no more than "
1274                                                  "this many items.")
1275                 },
1276                 &from_collapse_limit,
1277                 8, 1, INT_MAX, NULL, NULL
1278         },
1279         {
1280                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1281                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1282                                                  "constructs are not flattened."),
1283                         gettext_noop("The planner will flatten explicit JOIN "
1284                                                  "constructs into lists of FROM items whenever a "
1285                                                  "list of no more than this many items would result.")
1286                 },
1287                 &join_collapse_limit,
1288                 8, 1, INT_MAX, NULL, NULL
1289         },
1290         {
1291                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1292                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1293                         NULL
1294                 },
1295                 &geqo_threshold,
1296                 12, 2, INT_MAX, NULL, NULL
1297         },
1298         {
1299                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1300                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1301                         NULL
1302                 },
1303                 &Geqo_effort,
1304                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1305         },
1306         {
1307                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1308                         gettext_noop("GEQO: number of individuals in the population."),
1309                         gettext_noop("Zero selects a suitable default value.")
1310                 },
1311                 &Geqo_pool_size,
1312                 0, 0, INT_MAX, NULL, NULL
1313         },
1314         {
1315                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1316                         gettext_noop("GEQO: number of iterations of the algorithm."),
1317                         gettext_noop("Zero selects a suitable default value.")
1318                 },
1319                 &Geqo_generations,
1320                 0, 0, INT_MAX, NULL, NULL
1321         },
1322
1323         {
1324                 /* This is PGC_SIGHUP so all backends have the same value. */
1325                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1326                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1327                         NULL,
1328                         GUC_UNIT_MS
1329                 },
1330                 &DeadlockTimeout,
1331                 1000, 1, INT_MAX / 1000, NULL, NULL
1332         },
1333
1334         /*
1335          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1336          * 4*MaxBackends without any overflow check.  This check is made in
1337          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1338          * plus autovacuum_max_workers.
1339          *
1340          * Likewise we have to limit NBuffers to INT_MAX/2.
1341          */
1342         {
1343                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1344                         gettext_noop("Sets the maximum number of concurrent connections."),
1345                         NULL
1346                 },
1347                 &MaxConnections,
1348                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1349         },
1350
1351         {
1352                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1353                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1354                         NULL
1355                 },
1356                 &ReservedBackends,
1357                 3, 0, INT_MAX / 4, NULL, NULL
1358         },
1359
1360         {
1361                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1362                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1363                         NULL,
1364                         GUC_UNIT_BLOCKS
1365                 },
1366                 &NBuffers,
1367                 1024, 16, INT_MAX / 2, NULL, NULL
1368         },
1369
1370         {
1371                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1372                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1373                         NULL,
1374                         GUC_UNIT_BLOCKS
1375                 },
1376                 &num_temp_buffers,
1377                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1378         },
1379
1380         {
1381                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1382                         gettext_noop("Sets the TCP port the server listens on."),
1383                         NULL
1384                 },
1385                 &PostPortNumber,
1386                 DEF_PGPORT, 1, 65535, NULL, NULL
1387         },
1388
1389         {
1390                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1391                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1392                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1393                                                  "permission set. The parameter value is expected to be a numeric mode "
1394                                                  "specification in the form accepted by the chmod and umask system "
1395                                                  "calls. (To use the customary octal format the number must start with "
1396                                                  "a 0 (zero).)")
1397                 },
1398                 &Unix_socket_permissions,
1399                 0777, 0000, 0777, NULL, NULL
1400         },
1401
1402         {
1403                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1404                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1405                         gettext_noop("This much memory can be used by each internal "
1406                                                  "sort operation and hash table before switching to "
1407                                                  "temporary disk files."),
1408                         GUC_UNIT_KB
1409                 },
1410                 &work_mem,
1411                 1024, 64, MAX_KILOBYTES, NULL, NULL
1412         },
1413
1414         {
1415                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1416                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1417                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1418                         GUC_UNIT_KB
1419                 },
1420                 &maintenance_work_mem,
1421                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1422         },
1423
1424         {
1425                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1426                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1427                         NULL,
1428                         GUC_UNIT_KB
1429                 },
1430                 &max_stack_depth,
1431                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1432         },
1433
1434         {
1435                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1436                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1437                         NULL
1438                 },
1439                 &VacuumCostPageHit,
1440                 1, 0, 10000, NULL, NULL
1441         },
1442
1443         {
1444                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1445                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1446                         NULL
1447                 },
1448                 &VacuumCostPageMiss,
1449                 10, 0, 10000, NULL, NULL
1450         },
1451
1452         {
1453                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1454                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1455                         NULL
1456                 },
1457                 &VacuumCostPageDirty,
1458                 20, 0, 10000, NULL, NULL
1459         },
1460
1461         {
1462                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1463                         gettext_noop("Vacuum cost amount available before napping."),
1464                         NULL
1465                 },
1466                 &VacuumCostLimit,
1467                 200, 1, 10000, NULL, NULL
1468         },
1469
1470         {
1471                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1472                         gettext_noop("Vacuum cost delay in milliseconds."),
1473                         NULL,
1474                         GUC_UNIT_MS
1475                 },
1476                 &VacuumCostDelay,
1477                 0, 0, 100, NULL, NULL
1478         },
1479
1480         {
1481                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1482                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1483                         NULL,
1484                         GUC_UNIT_MS
1485                 },
1486                 &autovacuum_vac_cost_delay,
1487                 20, -1, 100, NULL, NULL
1488         },
1489
1490         {
1491                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1492                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1493                         NULL
1494                 },
1495                 &autovacuum_vac_cost_limit,
1496                 -1, -1, 10000, NULL, NULL
1497         },
1498
1499         {
1500                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1501                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1502                         NULL
1503                 },
1504                 &max_files_per_process,
1505                 1000, 25, INT_MAX, NULL, NULL
1506         },
1507
1508         {
1509                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1510                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1511                         NULL
1512                 },
1513                 &max_prepared_xacts,
1514                 0, 0, INT_MAX / 4, NULL, NULL
1515         },
1516
1517 #ifdef LOCK_DEBUG
1518         {
1519                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1520                         gettext_noop("No description available."),
1521                         NULL,
1522                         GUC_NOT_IN_SAMPLE
1523                 },
1524                 &Trace_lock_oidmin,
1525                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1526         },
1527         {
1528                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1529                         gettext_noop("No description available."),
1530                         NULL,
1531                         GUC_NOT_IN_SAMPLE
1532                 },
1533                 &Trace_lock_table,
1534                 0, 0, INT_MAX, NULL, NULL
1535         },
1536 #endif
1537
1538         {
1539                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1540                         gettext_noop("Sets the maximum allowed duration of any statement."),
1541                         gettext_noop("A value of 0 turns off the timeout."),
1542                         GUC_UNIT_MS
1543                 },
1544                 &StatementTimeout,
1545                 0, 0, INT_MAX, NULL, NULL
1546         },
1547
1548         {
1549                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1550                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1551                         NULL
1552                 },
1553                 &vacuum_freeze_min_age,
1554                 50000000, 0, 1000000000, NULL, NULL
1555         },
1556
1557         {
1558                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1559                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1560                         NULL
1561                 },
1562                 &vacuum_freeze_table_age,
1563                 150000000, 0, 2000000000, NULL, NULL
1564         },
1565
1566         {
1567                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1568                         gettext_noop("Sets the maximum number of locks per transaction."),
1569                         gettext_noop("The shared lock table is sized on the assumption that "
1570                           "at most max_locks_per_transaction * max_connections distinct "
1571                                                  "objects will need to be locked at any one time.")
1572                 },
1573                 &max_locks_per_xact,
1574                 64, 10, INT_MAX, NULL, NULL
1575         },
1576
1577         {
1578                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1579                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1580                         NULL,
1581                         GUC_UNIT_S
1582                 },
1583                 &AuthenticationTimeout,
1584                 60, 1, 600, NULL, NULL
1585         },
1586
1587         {
1588                 /* Not for general use */
1589                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1590                         gettext_noop("Waits N seconds on connection startup before authentication."),
1591                         gettext_noop("This allows attaching a debugger to the process."),
1592                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1593                 },
1594                 &PreAuthDelay,
1595                 0, 0, 60, NULL, NULL
1596         },
1597
1598         {
1599                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1600                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1601                         NULL
1602                 },
1603                 &CheckPointSegments,
1604                 3, 1, INT_MAX, NULL, NULL
1605         },
1606
1607         {
1608                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1609                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1610                         NULL,
1611                         GUC_UNIT_S
1612                 },
1613                 &CheckPointTimeout,
1614                 300, 30, 3600, NULL, NULL
1615         },
1616
1617         {
1618                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1619                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1620                                                  "frequently than this."),
1621                         gettext_noop("Write a message to the server log if checkpoints "
1622                         "caused by the filling of checkpoint segment files happens more "
1623                                                  "frequently than this number of seconds. Zero turns off the warning."),
1624                         GUC_UNIT_S
1625                 },
1626                 &CheckPointWarning,
1627                 30, 0, INT_MAX, NULL, NULL
1628         },
1629
1630         {
1631                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1632                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1633                         NULL,
1634                         GUC_UNIT_XBLOCKS
1635                 },
1636                 &XLOGbuffers,
1637                 8, 4, INT_MAX, NULL, NULL
1638         },
1639
1640         {
1641                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1642                         gettext_noop("WAL writer sleep time between WAL flushes."),
1643                         NULL,
1644                         GUC_UNIT_MS
1645                 },
1646                 &WalWriterDelay,
1647                 200, 1, 10000, NULL, NULL
1648         },
1649
1650         {
1651                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1652                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1653                                                  "flushing WAL to disk."),
1654                         NULL
1655                 },
1656                 &CommitDelay,
1657                 0, 0, 100000, NULL, NULL
1658         },
1659
1660         {
1661                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1662                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1663                                                  "commit_delay."),
1664                         NULL
1665                 },
1666                 &CommitSiblings,
1667                 5, 1, 1000, NULL, NULL
1668         },
1669
1670         {
1671                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1672                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1673                         gettext_noop("This affects real, double precision, and geometric data types. "
1674                          "The parameter value is added to the standard number of digits "
1675                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1676                 },
1677                 &extra_float_digits,
1678                 0, -15, 2, NULL, NULL
1679         },
1680
1681         {
1682                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1683                         gettext_noop("Sets the minimum execution time above which "
1684                                                  "statements will be logged."),
1685                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1686                         GUC_UNIT_MS
1687                 },
1688                 &log_min_duration_statement,
1689                 -1, -1, INT_MAX / 1000, NULL, NULL
1690         },
1691
1692         {
1693                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1694                         gettext_noop("Sets the minimum execution time above which "
1695                                                  "autovacuum actions will be logged."),
1696                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1697                         GUC_UNIT_MS
1698                 },
1699                 &Log_autovacuum_min_duration,
1700                 -1, -1, INT_MAX / 1000, NULL, NULL
1701         },
1702
1703         {
1704                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1705                         gettext_noop("Background writer sleep time between rounds."),
1706                         NULL,
1707                         GUC_UNIT_MS
1708                 },
1709                 &BgWriterDelay,
1710                 200, 10, 10000, NULL, NULL
1711         },
1712
1713         {
1714                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1715                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1716                         NULL
1717                 },
1718                 &bgwriter_lru_maxpages,
1719                 100, 0, 1000, NULL, NULL
1720         },
1721
1722         {
1723                 {"effective_io_concurrency",
1724 #ifdef USE_PREFETCH
1725                         PGC_USERSET,
1726 #else
1727                         PGC_INTERNAL,
1728 #endif
1729                         RESOURCES,
1730                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
1731                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
1732                 },
1733                 &effective_io_concurrency,
1734 #ifdef USE_PREFETCH
1735                 1, 0, 1000,
1736 #else
1737                 0, 0, 0,
1738 #endif
1739                 assign_effective_io_concurrency, NULL
1740         },
1741
1742         {
1743                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1744                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1745                         NULL,
1746                         GUC_UNIT_MIN
1747                 },
1748                 &Log_RotationAge,
1749                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1750         },
1751
1752         {
1753                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1754                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1755                         NULL,
1756                         GUC_UNIT_KB
1757                 },
1758                 &Log_RotationSize,
1759                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1760         },
1761
1762         {
1763                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1764                         gettext_noop("Shows the maximum number of function arguments."),
1765                         NULL,
1766                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1767                 },
1768                 &max_function_args,
1769                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1770         },
1771
1772         {
1773                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1774                         gettext_noop("Shows the maximum number of index keys."),
1775                         NULL,
1776                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1777                 },
1778                 &max_index_keys,
1779                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1780         },
1781
1782         {
1783                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1784                         gettext_noop("Shows the maximum identifier length."),
1785                         NULL,
1786                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1787                 },
1788                 &max_identifier_length,
1789                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1790         },
1791
1792         {
1793                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1794                         gettext_noop("Shows the size of a disk block."),
1795                         NULL,
1796                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1797                 },
1798                 &block_size,
1799                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1800         },
1801
1802         {
1803                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1804                         gettext_noop("Shows the number of pages per disk file."),
1805                         NULL,
1806                         GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1807                 },
1808                 &segment_size,
1809                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1810         },
1811
1812         {
1813                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1814                         gettext_noop("Shows the block size in the write ahead log."),
1815                         NULL,
1816                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1817                 },
1818                 &wal_block_size,
1819                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1820         },
1821
1822         {
1823                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1824                         gettext_noop("Shows the number of pages per write ahead log segment."),
1825                         NULL,
1826                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1827                 },
1828                 &wal_segment_size,
1829                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1830                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1831                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1832                 NULL, NULL
1833         },
1834
1835         {
1836                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1837                         gettext_noop("Time to sleep between autovacuum runs."),
1838                         NULL,
1839                         GUC_UNIT_S
1840                 },
1841                 &autovacuum_naptime,
1842                 60, 1, INT_MAX / 1000, NULL, NULL
1843         },
1844         {
1845                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1846                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1847                         NULL
1848                 },
1849                 &autovacuum_vac_thresh,
1850                 50, 0, INT_MAX, NULL, NULL
1851         },
1852         {
1853                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1854                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1855                         NULL
1856                 },
1857                 &autovacuum_anl_thresh,
1858                 50, 0, INT_MAX, NULL, NULL
1859         },
1860         {
1861                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1862                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1863                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1864                         NULL
1865                 },
1866                 &autovacuum_freeze_max_age,
1867                 200000000, 100000000, 2000000000, NULL, NULL
1868         },
1869         {
1870                 /* see max_connections */
1871                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1872                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1873                         NULL
1874                 },
1875                 &autovacuum_max_workers,
1876                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1877         },
1878
1879         {
1880                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1881                         gettext_noop("Time between issuing TCP keepalives."),
1882                         gettext_noop("A value of 0 uses the system default."),
1883                         GUC_UNIT_S
1884                 },
1885                 &tcp_keepalives_idle,
1886                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1887         },
1888
1889         {
1890                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1891                         gettext_noop("Time between TCP keepalive retransmits."),
1892                         gettext_noop("A value of 0 uses the system default."),
1893                         GUC_UNIT_S
1894                 },
1895                 &tcp_keepalives_interval,
1896                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1897         },
1898
1899         {
1900                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1901                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1902                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1903                                                  "lost before a connection is considered dead. A value of 0 uses the "
1904                                                  "system default."),
1905                 },
1906                 &tcp_keepalives_count,
1907                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1908         },
1909
1910         {
1911                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1912                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1913                         NULL,
1914                         0
1915                 },
1916                 &GinFuzzySearchLimit,
1917                 0, 0, INT_MAX, NULL, NULL
1918         },
1919
1920         {
1921                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1922                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1923                         gettext_noop("That is, the portion of the kernel's disk cache that "
1924                                                  "will be used for PostgreSQL data files. This is measured in disk "
1925                                                  "pages, which are normally 8 kB each."),
1926                         GUC_UNIT_BLOCKS,
1927                 },
1928                 &effective_cache_size,
1929                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1930         },
1931
1932         {
1933                 /* Can't be set in postgresql.conf */
1934                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1935                         gettext_noop("Shows the server version as an integer."),
1936                         NULL,
1937                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1938                 },
1939                 &server_version_num,
1940                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1941         },
1942
1943         {
1944                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1945                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1946                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1947                         GUC_UNIT_KB
1948                 },
1949                 &log_temp_files,
1950                 -1, -1, INT_MAX, NULL, NULL
1951         },
1952
1953         {
1954                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1955                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1956                         NULL,
1957                 },
1958                 &pgstat_track_activity_query_size,
1959                 1024, 100, 102400, NULL, NULL
1960         },
1961
1962         /* End-of-list marker */
1963         {
1964                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1965         }
1966 };
1967
1968
1969 static struct config_real ConfigureNamesReal[] =
1970 {
1971         {
1972                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1973                         gettext_noop("Sets the planner's estimate of the cost of a "
1974                                                  "sequentially fetched disk page."),
1975                         NULL
1976                 },
1977                 &seq_page_cost,
1978                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1979         },
1980         {
1981                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1982                         gettext_noop("Sets the planner's estimate of the cost of a "
1983                                                  "nonsequentially fetched disk page."),
1984                         NULL
1985                 },
1986                 &random_page_cost,
1987                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1988         },
1989         {
1990                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1991                         gettext_noop("Sets the planner's estimate of the cost of "
1992                                                  "processing each tuple (row)."),
1993                         NULL
1994                 },
1995                 &cpu_tuple_cost,
1996                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1997         },
1998         {
1999                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
2000                         gettext_noop("Sets the planner's estimate of the cost of "
2001                                                  "processing each index entry during an index scan."),
2002                         NULL
2003                 },
2004                 &cpu_index_tuple_cost,
2005                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
2006         },
2007         {
2008                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
2009                         gettext_noop("Sets the planner's estimate of the cost of "
2010                                                  "processing each operator or function call."),
2011                         NULL
2012                 },
2013                 &cpu_operator_cost,
2014                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
2015         },
2016
2017         {
2018                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2019                         gettext_noop("Sets the planner's estimate of the fraction of "
2020                                                  "a cursor's rows that will be retrieved."),
2021                         NULL
2022                 },
2023                 &cursor_tuple_fraction,
2024                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
2025         },
2026
2027         {
2028                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2029                         gettext_noop("GEQO: selective pressure within the population."),
2030                         NULL
2031                 },
2032                 &Geqo_selection_bias,
2033                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
2034                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
2035         },
2036         {
2037                 {"geqo_seed", PGC_USERSET, QUERY_TUNING_GEQO,
2038                         gettext_noop("GEQO: seed for random path selection."),
2039                         NULL
2040                 },
2041                 &Geqo_seed,
2042                 0.0, 0.0, 1.0, NULL, NULL
2043         },
2044
2045         {
2046                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2047                         gettext_noop("Multiple of the average buffer usage to free per round."),
2048                         NULL
2049                 },
2050                 &bgwriter_lru_multiplier,
2051                 2.0, 0.0, 10.0, NULL, NULL
2052         },
2053
2054         {
2055                 {"seed", PGC_USERSET, UNGROUPED,
2056                         gettext_noop("Sets the seed for random-number generation."),
2057                         NULL,
2058                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2059                 },
2060                 &phony_random_seed,
2061                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2062         },
2063
2064         {
2065                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2066                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2067                         NULL
2068                 },
2069                 &autovacuum_vac_scale,
2070                 0.2, 0.0, 100.0, NULL, NULL
2071         },
2072         {
2073                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2074                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2075                         NULL
2076                 },
2077                 &autovacuum_anl_scale,
2078                 0.1, 0.0, 100.0, NULL, NULL
2079         },
2080
2081         {
2082                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2083                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2084                         NULL
2085                 },
2086                 &CheckPointCompletionTarget,
2087                 0.5, 0.0, 1.0, NULL, NULL
2088         },
2089
2090         /* End-of-list marker */
2091         {
2092                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2093         }
2094 };
2095
2096
2097 static struct config_string ConfigureNamesString[] =
2098 {
2099         {
2100                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2101                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2102                         NULL
2103                 },
2104                 &XLogArchiveCommand,
2105                 "", NULL, show_archive_command
2106         },
2107
2108         {
2109                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2110                         gettext_noop("Sets the client's character set encoding."),
2111                         NULL,
2112                         GUC_IS_NAME | GUC_REPORT
2113                 },
2114                 &client_encoding_string,
2115                 "SQL_ASCII", assign_client_encoding, NULL
2116         },
2117
2118         {
2119                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2120                         gettext_noop("Controls information prefixed to each log line."),
2121                         gettext_noop("If blank, no prefix is used.")
2122                 },
2123                 &Log_line_prefix,
2124                 "", NULL, NULL
2125         },
2126
2127         {
2128                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2129                         gettext_noop("Sets the time zone to use in log messages."),
2130                         NULL
2131                 },
2132                 &log_timezone_string,
2133                 "UNKNOWN", assign_log_timezone, show_log_timezone
2134         },
2135
2136         {
2137                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2138                         gettext_noop("Sets the display format for date and time values."),
2139                         gettext_noop("Also controls interpretation of ambiguous "
2140                                                  "date inputs."),
2141                         GUC_LIST_INPUT | GUC_REPORT
2142                 },
2143                 &datestyle_string,
2144                 "ISO, MDY", assign_datestyle, NULL
2145         },
2146
2147         {
2148                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2149                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2150                         gettext_noop("An empty string selects the database's default tablespace."),
2151                         GUC_IS_NAME
2152                 },
2153                 &default_tablespace,
2154                 "", assign_default_tablespace, NULL
2155         },
2156
2157         {
2158                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2159                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2160                         NULL,
2161                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2162                 },
2163                 &temp_tablespaces,
2164                 "", assign_temp_tablespaces, NULL
2165         },
2166
2167         {
2168                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2169                         gettext_noop("Sets the path for dynamically loadable modules."),
2170                         gettext_noop("If a dynamically loadable module needs to be opened and "
2171                                                  "the specified name does not have a directory component (i.e., the "
2172                                                  "name does not contain a slash), the system will search this path for "
2173                                                  "the specified file."),
2174                         GUC_SUPERUSER_ONLY
2175                 },
2176                 &Dynamic_library_path,
2177                 "$libdir", NULL, NULL
2178         },
2179
2180         {
2181                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2182                         gettext_noop("Sets the location of the Kerberos server key file."),
2183                         NULL,
2184                         GUC_SUPERUSER_ONLY
2185                 },
2186                 &pg_krb_server_keyfile,
2187                 PG_KRB_SRVTAB, NULL, NULL
2188         },
2189
2190         {
2191                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2192                         gettext_noop("Sets the name of the Kerberos service."),
2193                         NULL
2194                 },
2195                 &pg_krb_srvnam,
2196                 PG_KRB_SRVNAM, NULL, NULL
2197         },
2198
2199         {
2200                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2201                         gettext_noop("Sets the Bonjour broadcast service name."),
2202                         NULL
2203                 },
2204                 &bonjour_name,
2205                 "", NULL, NULL
2206         },
2207
2208         /* See main.c about why defaults for LC_foo are not all alike */
2209
2210         {
2211                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2212                         gettext_noop("Shows the collation order locale."),
2213                         NULL,
2214                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2215                 },
2216                 &locale_collate,
2217                 "C", NULL, NULL
2218         },
2219
2220         {
2221                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2222                         gettext_noop("Shows the character classification and case conversion locale."),
2223                         NULL,
2224                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2225                 },
2226                 &locale_ctype,
2227                 "C", NULL, NULL
2228         },
2229
2230         {
2231                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2232                         gettext_noop("Sets the language in which messages are displayed."),
2233                         NULL
2234                 },
2235                 &locale_messages,
2236                 "", locale_messages_assign, NULL
2237         },
2238
2239         {
2240                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2241                         gettext_noop("Sets the locale for formatting monetary amounts."),
2242                         NULL
2243                 },
2244                 &locale_monetary,
2245                 "C", locale_monetary_assign, NULL
2246         },
2247
2248         {
2249                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2250                         gettext_noop("Sets the locale for formatting numbers."),
2251                         NULL
2252                 },
2253                 &locale_numeric,
2254                 "C", locale_numeric_assign, NULL
2255         },
2256
2257         {
2258                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2259                         gettext_noop("Sets the locale for formatting date and time values."),
2260                         NULL
2261                 },
2262                 &locale_time,
2263                 "C", locale_time_assign, NULL
2264         },
2265
2266         {
2267                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2268                         gettext_noop("Lists shared libraries to preload into server."),
2269                         NULL,
2270                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2271                 },
2272                 &shared_preload_libraries_string,
2273                 "", NULL, NULL
2274         },
2275
2276         {
2277                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2278                         gettext_noop("Lists shared libraries to preload into each backend."),
2279                         NULL,
2280                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2281                 },
2282                 &local_preload_libraries_string,
2283                 "", NULL, NULL
2284         },
2285
2286         {
2287                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2288                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2289                         NULL,
2290                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2291                 },
2292                 &namespace_search_path,
2293                 "\"$user\",public", assign_search_path, NULL
2294         },
2295
2296         {
2297                 /* Can't be set in postgresql.conf */
2298                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2299                         gettext_noop("Sets the server (database) character set encoding."),
2300                         NULL,
2301                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2302                 },
2303                 &server_encoding_string,
2304                 "SQL_ASCII", NULL, NULL
2305         },
2306
2307         {
2308                 /* Can't be set in postgresql.conf */
2309                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2310                         gettext_noop("Shows the server version."),
2311                         NULL,
2312                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2313                 },
2314                 &server_version_string,
2315                 PG_VERSION, NULL, NULL
2316         },
2317
2318         {
2319                 /* Not for general use --- used by SET ROLE */
2320                 {"role", PGC_USERSET, UNGROUPED,
2321                         gettext_noop("Sets the current role."),
2322                         NULL,
2323                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2324                 },
2325                 &role_string,
2326                 "none", assign_role, show_role
2327         },
2328
2329         {
2330                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2331                 {"session_authorization", PGC_USERSET, UNGROUPED,
2332                         gettext_noop("Sets the session user name."),
2333                         NULL,
2334                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2335                 },
2336                 &session_authorization_string,
2337                 NULL, assign_session_authorization, show_session_authorization
2338         },
2339
2340         {
2341                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2342                         gettext_noop("Sets the destination for server log output."),
2343                         gettext_noop("Valid values are combinations of \"stderr\", "
2344                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2345                                                  "depending on the platform."),
2346                         GUC_LIST_INPUT
2347                 },
2348                 &log_destination_string,
2349                 "stderr", assign_log_destination, NULL
2350         },
2351         {
2352                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2353                         gettext_noop("Sets the destination directory for log files."),
2354                         gettext_noop("Can be specified as relative to the data directory "
2355                                                  "or as absolute path."),
2356                         GUC_SUPERUSER_ONLY
2357                 },
2358                 &Log_directory,
2359                 "pg_log", assign_canonical_path, NULL
2360         },
2361         {
2362                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2363                         gettext_noop("Sets the file name pattern for log files."),
2364                         NULL,
2365                         GUC_SUPERUSER_ONLY
2366                 },
2367                 &Log_filename,
2368                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2369         },
2370
2371 #ifdef HAVE_SYSLOG
2372         {
2373                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2374                         gettext_noop("Sets the program name used to identify PostgreSQL "
2375                                                  "messages in syslog."),
2376                         NULL
2377                 },
2378                 &syslog_ident_str,
2379                 "postgres", assign_syslog_ident, NULL
2380         },
2381 #endif
2382
2383         {
2384                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2385                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2386                         NULL,
2387                         GUC_REPORT
2388                 },
2389                 &timezone_string,
2390                 "UNKNOWN", assign_timezone, show_timezone
2391         },
2392         {
2393                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2394                         gettext_noop("Selects a file of time zone abbreviations."),
2395                         NULL
2396                 },
2397                 &timezone_abbreviations_string,
2398                 "UNKNOWN", assign_timezone_abbreviations, NULL
2399         },
2400
2401         {
2402                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2403                         gettext_noop("Sets the current transaction's isolation level."),
2404                         NULL,
2405                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2406                 },
2407                 &XactIsoLevel_string,
2408                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2409         },
2410
2411         {
2412                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2413                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2414                         gettext_noop("The owning user of the socket is always the user "
2415                                                  "that starts the server.")
2416                 },
2417                 &Unix_socket_group,
2418                 "", NULL, NULL
2419         },
2420
2421         {
2422                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2423                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2424                         NULL,
2425                         GUC_SUPERUSER_ONLY
2426                 },
2427                 &UnixSocketDir,
2428                 "", assign_canonical_path, NULL
2429         },
2430
2431         {
2432                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2433                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2434                         NULL,
2435                         GUC_LIST_INPUT
2436                 },
2437                 &ListenAddresses,
2438                 "localhost", NULL, NULL
2439         },
2440
2441         {
2442                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2443                         gettext_noop("Sets the list of known custom variable classes."),
2444                         NULL,
2445                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2446                 },
2447                 &custom_variable_classes,
2448                 NULL, assign_custom_variable_classes, NULL
2449         },
2450
2451         {
2452                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2453                         gettext_noop("Sets the server's data directory."),
2454                         NULL,
2455                         GUC_SUPERUSER_ONLY
2456                 },
2457                 &data_directory,
2458                 NULL, NULL, NULL
2459         },
2460
2461         {
2462                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2463                         gettext_noop("Sets the server's main configuration file."),
2464                         NULL,
2465                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2466                 },
2467                 &ConfigFileName,
2468                 NULL, NULL, NULL
2469         },
2470
2471         {
2472                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2473                         gettext_noop("Sets the server's \"hba\" configuration file."),
2474                         NULL,
2475                         GUC_SUPERUSER_ONLY
2476                 },
2477                 &HbaFileName,
2478                 NULL, NULL, NULL
2479         },
2480
2481         {
2482                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2483                         gettext_noop("Sets the server's \"ident\" configuration file."),
2484                         NULL,
2485                         GUC_SUPERUSER_ONLY
2486                 },
2487                 &IdentFileName,
2488                 NULL, NULL, NULL
2489         },
2490
2491         {
2492                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2493                         gettext_noop("Writes the postmaster PID to the specified file."),
2494                         NULL,
2495                         GUC_SUPERUSER_ONLY
2496                 },
2497                 &external_pid_file,
2498                 NULL, assign_canonical_path, NULL
2499         },
2500
2501         {
2502                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2503                         gettext_noop("Writes temporary statistics files to the specified directory."),
2504                         NULL,
2505                         GUC_SUPERUSER_ONLY
2506                 },
2507                 &pgstat_temp_directory,
2508                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2509         },
2510
2511         {
2512                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2513                         gettext_noop("Sets default text search configuration."),
2514                         NULL
2515                 },
2516                 &TSCurrentConfig,
2517                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2518         },
2519
2520 #ifdef USE_SSL
2521         {
2522                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2523                         gettext_noop("Sets the list of allowed SSL ciphers."),
2524                         NULL,
2525                         GUC_SUPERUSER_ONLY
2526                 },
2527                 &SSLCipherSuites,
2528                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2529         },
2530 #endif   /* USE_SSL */
2531
2532         /* End-of-list marker */
2533         {
2534                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2535         }
2536 };
2537
2538
2539 static struct config_enum ConfigureNamesEnum[] =
2540 {
2541         {
2542                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2543                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2544                         NULL
2545                 },
2546                 &backslash_quote,
2547                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2548         },
2549
2550         {
2551                 {"bytea_output", PGC_USERSET, CLIENT_CONN_STATEMENT,
2552                         gettext_noop("Sets the output format for bytea."),
2553                         NULL
2554                 },
2555                 &bytea_output,
2556                 BYTEA_OUTPUT_HEX, bytea_output_options, NULL, NULL
2557         },
2558
2559         {
2560                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2561                         gettext_noop("Sets the message levels that are sent to the client."),
2562                         gettext_noop("Each level includes all the levels that follow it. The later"
2563                                                  " the level, the fewer messages are sent.")
2564                 },
2565                 &client_min_messages,
2566                 NOTICE, client_message_level_options, NULL, NULL
2567         },
2568
2569         {
2570                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2571                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2572                         gettext_noop("Table scans will be skipped if their constraints"
2573                                                  " guarantee that no rows match the query.")
2574                 },
2575                 &constraint_exclusion,
2576                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2577                 NULL, NULL
2578         },
2579
2580         {
2581                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2582                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2583                         NULL
2584                 },
2585                 &DefaultXactIsoLevel,
2586                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2587         },
2588
2589         {
2590                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2591                         gettext_noop("Sets the display format for interval values."),
2592                         NULL,
2593                         GUC_REPORT
2594                 },
2595                 &IntervalStyle,
2596                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2597         },
2598
2599         {
2600                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2601                         gettext_noop("Sets the verbosity of logged messages."),
2602                         NULL
2603                 },
2604                 &Log_error_verbosity,
2605                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2606         },
2607
2608         {
2609                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2610                         gettext_noop("Sets the message levels that are logged."),
2611                         gettext_noop("Each level includes all the levels that follow it. The later"
2612                                                  " the level, the fewer messages are sent.")
2613                 },
2614                 &log_min_messages,
2615                 WARNING, server_message_level_options, NULL, NULL
2616         },
2617
2618         {
2619                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2620                         gettext_noop("Causes all statements generating error at or above this level to be 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_error_statement,
2625                 ERROR, server_message_level_options, NULL, NULL
2626         },
2627
2628         {
2629                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2630                         gettext_noop("Sets the type of statements logged."),
2631                         NULL
2632                 },
2633                 &log_statement,
2634                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2635         },
2636
2637 #ifdef HAVE_SYSLOG
2638         {
2639                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2640                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2641                         NULL
2642                 },
2643                 &syslog_facility,
2644                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2645         },
2646 #endif
2647
2648         {
2649                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2650                         gettext_noop("Sets the regular expression \"flavor\"."),
2651                         NULL
2652                 },
2653                 &regex_flavor,
2654                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2655         },
2656
2657         {
2658                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2659                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2660                         NULL
2661                 },
2662                 &SessionReplicationRole,
2663                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2664                 assign_session_replication_role, NULL
2665         },
2666
2667         {
2668                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2669                         gettext_noop("Collects function-level statistics on database activity."),
2670                         NULL
2671                 },
2672                 &pgstat_track_functions,
2673                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2674         },
2675
2676         {
2677                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2678                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2679                         NULL
2680                 },
2681                 &sync_method,
2682                 DEFAULT_SYNC_METHOD, sync_method_options,
2683                 assign_xlog_sync_method, NULL
2684         },
2685
2686         {
2687                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2688                         gettext_noop("Sets how binary values are to be encoded in XML."),
2689                         NULL
2690                 },
2691                 &xmlbinary,
2692                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2693         },
2694
2695         {
2696                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2697                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2698                                                  "operations is to be considered as documents or content fragments."),
2699                         NULL
2700                 },
2701                 &xmloption,
2702                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2703         },
2704
2705
2706         /* End-of-list marker */
2707         {
2708                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2709         }
2710 };
2711
2712 /******** end of options list ********/
2713
2714
2715 /*
2716  * To allow continued support of obsolete names for GUC variables, we apply
2717  * the following mappings to any unrecognized name.  Note that an old name
2718  * should be mapped to a new one only if the new variable has very similar
2719  * semantics to the old.
2720  */
2721 static const char *const map_old_guc_names[] = {
2722         "sort_mem", "work_mem",
2723         "vacuum_mem", "maintenance_work_mem",
2724         NULL
2725 };
2726
2727
2728 /*
2729  * Actual lookup of variables is done through this single, sorted array.
2730  */
2731 static struct config_generic **guc_variables;
2732
2733 /* Current number of variables contained in the vector */
2734 static int      num_guc_variables;
2735
2736 /* Vector capacity */
2737 static int      size_guc_variables;
2738
2739
2740 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2741
2742 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2743
2744 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2745
2746
2747 static int      guc_var_compare(const void *a, const void *b);
2748 static int      guc_name_compare(const char *namea, const char *nameb);
2749 static void InitializeOneGUCOption(struct config_generic * gconf);
2750 static void push_old_value(struct config_generic * gconf, GucAction action);
2751 static void ReportGUCOption(struct config_generic * record);
2752 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2753 static void ShowAllGUCConfig(DestReceiver *dest);
2754 static char *_ShowOption(struct config_generic * record, bool use_units);
2755 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2756
2757
2758 /*
2759  * Some infrastructure for checking malloc/strdup/realloc calls
2760  */
2761 static void *
2762 guc_malloc(int elevel, size_t size)
2763 {
2764         void       *data;
2765
2766         data = malloc(size);
2767         if (data == NULL)
2768                 ereport(elevel,
2769                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2770                                  errmsg("out of memory")));
2771         return data;
2772 }
2773
2774 static void *
2775 guc_realloc(int elevel, void *old, size_t size)
2776 {
2777         void       *data;
2778
2779         data = realloc(old, size);
2780         if (data == NULL)
2781                 ereport(elevel,
2782                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2783                                  errmsg("out of memory")));
2784         return data;
2785 }
2786
2787 static char *
2788 guc_strdup(int elevel, const char *src)
2789 {
2790         char       *data;
2791
2792         data = strdup(src);
2793         if (data == NULL)
2794                 ereport(elevel,
2795                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2796                                  errmsg("out of memory")));
2797         return data;
2798 }
2799
2800
2801 /*
2802  * Support for assigning to a field of a string GUC item.  Free the prior
2803  * value if it's not referenced anywhere else in the item (including stacked
2804  * states).
2805  */
2806 static void
2807 set_string_field(struct config_string * conf, char **field, char *newval)
2808 {
2809         char       *oldval = *field;
2810         GucStack   *stack;
2811
2812         /* Do the assignment */
2813         *field = newval;
2814
2815         /* Exit if any duplicate references, or if old value was NULL anyway */
2816         if (oldval == NULL ||
2817                 oldval == *(conf->variable) ||
2818                 oldval == conf->reset_val ||
2819                 oldval == conf->boot_val)
2820                 return;
2821         for (stack = conf->gen.stack; stack; stack = stack->prev)
2822         {
2823                 if (oldval == stack->prior.stringval ||
2824                         oldval == stack->masked.stringval)
2825                         return;
2826         }
2827
2828         /* Not used anymore, so free it */
2829         free(oldval);
2830 }
2831
2832 /*
2833  * Detect whether strval is referenced anywhere in a GUC string item
2834  */
2835 static bool
2836 string_field_used(struct config_string * conf, char *strval)
2837 {
2838         GucStack   *stack;
2839
2840         if (strval == *(conf->variable) ||
2841                 strval == conf->reset_val ||
2842                 strval == conf->boot_val)
2843                 return true;
2844         for (stack = conf->gen.stack; stack; stack = stack->prev)
2845         {
2846                 if (strval == stack->prior.stringval ||
2847                         strval == stack->masked.stringval)
2848                         return true;
2849         }
2850         return false;
2851 }
2852
2853 /*
2854  * Support for copying a variable's active value into a stack entry
2855  */
2856 static void
2857 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2858 {
2859         switch (gconf->vartype)
2860         {
2861                 case PGC_BOOL:
2862                         val->boolval =
2863                                 *((struct config_bool *) gconf)->variable;
2864                         break;
2865                 case PGC_INT:
2866                         val->intval =
2867                                 *((struct config_int *) gconf)->variable;
2868                         break;
2869                 case PGC_REAL:
2870                         val->realval =
2871                                 *((struct config_real *) gconf)->variable;
2872                         break;
2873                 case PGC_STRING:
2874                         /* we assume stringval is NULL if not valid */
2875                         set_string_field((struct config_string *) gconf,
2876                                                          &(val->stringval),
2877                                                          *((struct config_string *) gconf)->variable);
2878                         break;
2879                 case PGC_ENUM:
2880                         val->enumval =
2881                                 *((struct config_enum *) gconf)->variable;
2882                         break;
2883         }
2884 }
2885
2886 /*
2887  * Support for discarding a no-longer-needed value in a stack entry
2888  */
2889 static void
2890 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2891 {
2892         switch (gconf->vartype)
2893         {
2894                 case PGC_BOOL:
2895                 case PGC_INT:
2896                 case PGC_REAL:
2897                 case PGC_ENUM:
2898                         /* no need to do anything */
2899                         break;
2900                 case PGC_STRING:
2901                         set_string_field((struct config_string *) gconf,
2902                                                          &(val->stringval),
2903                                                          NULL);
2904                         break;
2905         }
2906 }
2907
2908
2909 /*
2910  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2911  */
2912 struct config_generic **
2913 get_guc_variables(void)
2914 {
2915         return guc_variables;
2916 }
2917
2918
2919 /*
2920  * Build the sorted array.      This is split out so that it could be
2921  * re-executed after startup (eg, we could allow loadable modules to
2922  * add vars, and then we'd need to re-sort).
2923  */
2924 void
2925 build_guc_variables(void)
2926 {
2927         int                     size_vars;
2928         int                     num_vars = 0;
2929         struct config_generic **guc_vars;
2930         int                     i;
2931
2932         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2933         {
2934                 struct config_bool *conf = &ConfigureNamesBool[i];
2935
2936                 /* Rather than requiring vartype to be filled in by hand, do this: */
2937                 conf->gen.vartype = PGC_BOOL;
2938                 num_vars++;
2939         }
2940
2941         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2942         {
2943                 struct config_int *conf = &ConfigureNamesInt[i];
2944
2945                 conf->gen.vartype = PGC_INT;
2946                 num_vars++;
2947         }
2948
2949         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2950         {
2951                 struct config_real *conf = &ConfigureNamesReal[i];
2952
2953                 conf->gen.vartype = PGC_REAL;
2954                 num_vars++;
2955         }
2956
2957         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2958         {
2959                 struct config_string *conf = &ConfigureNamesString[i];
2960
2961                 conf->gen.vartype = PGC_STRING;
2962                 num_vars++;
2963         }
2964
2965         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2966         {
2967                 struct config_enum *conf = &ConfigureNamesEnum[i];
2968
2969                 conf->gen.vartype = PGC_ENUM;
2970                 num_vars++;
2971         }
2972
2973         /*
2974          * Create table with 20% slack
2975          */
2976         size_vars = num_vars + num_vars / 4;
2977
2978         guc_vars = (struct config_generic **)
2979                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2980
2981         num_vars = 0;
2982
2983         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2984                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2985
2986         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2987                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2988
2989         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2990                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2991
2992         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2993                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2994
2995         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2996                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2997
2998         if (guc_variables)
2999                 free(guc_variables);
3000         guc_variables = guc_vars;
3001         num_guc_variables = num_vars;
3002         size_guc_variables = size_vars;
3003         qsort((void *) guc_variables, num_guc_variables,
3004                   sizeof(struct config_generic *), guc_var_compare);
3005 }
3006
3007 /*
3008  * Add a new GUC variable to the list of known variables. The
3009  * list is expanded if needed.
3010  */
3011 static bool
3012 add_guc_variable(struct config_generic * var, int elevel)
3013 {
3014         if (num_guc_variables + 1 >= size_guc_variables)
3015         {
3016                 /*
3017                  * Increase the vector by 25%
3018                  */
3019                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
3020                 struct config_generic **guc_vars;
3021
3022                 if (size_vars == 0)
3023                 {
3024                         size_vars = 100;
3025                         guc_vars = (struct config_generic **)
3026                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
3027                 }
3028                 else
3029                 {
3030                         guc_vars = (struct config_generic **)
3031                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3032                 }
3033
3034                 if (guc_vars == NULL)
3035                         return false;           /* out of memory */
3036
3037                 guc_variables = guc_vars;
3038                 size_guc_variables = size_vars;
3039         }
3040         guc_variables[num_guc_variables++] = var;
3041         qsort((void *) guc_variables, num_guc_variables,
3042                   sizeof(struct config_generic *), guc_var_compare);
3043         return true;
3044 }
3045
3046 /*
3047  * Create and add a placeholder variable. It's presumed to belong
3048  * to a valid custom variable class at this point.
3049  */
3050 static struct config_generic *
3051 add_placeholder_variable(const char *name, int elevel)
3052 {
3053         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3054         struct config_string *var;
3055         struct config_generic *gen;
3056
3057         var = (struct config_string *) guc_malloc(elevel, sz);
3058         if (var == NULL)
3059                 return NULL;
3060         memset(var, 0, sz);
3061         gen = &var->gen;
3062
3063         gen->name = guc_strdup(elevel, name);
3064         if (gen->name == NULL)
3065         {
3066                 free(var);
3067                 return NULL;
3068         }
3069
3070         gen->context = PGC_USERSET;
3071         gen->group = CUSTOM_OPTIONS;
3072         gen->short_desc = "GUC placeholder variable";
3073         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3074         gen->vartype = PGC_STRING;
3075
3076         /*
3077          * The char* is allocated at the end of the struct since we have no
3078          * 'static' place to point to.  Note that the current value, as well as
3079          * the boot and reset values, start out NULL.
3080          */
3081         var->variable = (char **) (var + 1);
3082
3083         if (!add_guc_variable((struct config_generic *) var, elevel))
3084         {
3085                 free((void *) gen->name);
3086                 free(var);
3087                 return NULL;
3088         }
3089
3090         return gen;
3091 }
3092
3093 /*
3094  * Detect whether the portion of "name" before dotPos matches any custom
3095  * variable class name listed in custom_var_classes.  The latter must be
3096  * formatted the way that assign_custom_variable_classes does it, ie,
3097  * no whitespace.  NULL is valid for custom_var_classes.
3098  */
3099 static bool
3100 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3101 {
3102         bool            result = false;
3103         const char *ccs = custom_var_classes;
3104
3105         if (ccs != NULL)
3106         {
3107                 const char *start = ccs;
3108
3109                 for (;; ++ccs)
3110                 {
3111                         char            c = *ccs;
3112
3113                         if (c == '\0' || c == ',')
3114                         {
3115                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3116                                 {
3117                                         result = true;
3118                                         break;
3119                                 }
3120                                 if (c == '\0')
3121                                         break;
3122                                 start = ccs + 1;
3123                         }
3124                 }
3125         }
3126         return result;
3127 }
3128
3129 /*
3130  * Look up option NAME.  If it exists, return a pointer to its record,
3131  * else return NULL.  If create_placeholders is TRUE, we'll create a
3132  * placeholder record for a valid-looking custom variable name.
3133  */
3134 static struct config_generic *
3135 find_option(const char *name, bool create_placeholders, int elevel)
3136 {
3137         const char **key = &name;
3138         struct config_generic **res;
3139         int                     i;
3140
3141         Assert(name);
3142
3143         /*
3144          * By equating const char ** with struct config_generic *, we are assuming
3145          * the name field is first in config_generic.
3146          */
3147         res = (struct config_generic **) bsearch((void *) &key,
3148                                                                                          (void *) guc_variables,
3149                                                                                          num_guc_variables,
3150                                                                                          sizeof(struct config_generic *),
3151                                                                                          guc_var_compare);
3152         if (res)
3153                 return *res;
3154
3155         /*
3156          * See if the name is an obsolete name for a variable.  We assume that the
3157          * set of supported old names is short enough that a brute-force search is
3158          * the best way.
3159          */
3160         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3161         {
3162                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3163                         return find_option(map_old_guc_names[i + 1], false, elevel);
3164         }
3165
3166         if (create_placeholders)
3167         {
3168                 /*
3169                  * Check if the name is qualified, and if so, check if the qualifier
3170                  * matches any custom variable class.  If so, add a placeholder.
3171                  */
3172                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3173
3174                 if (dot != NULL &&
3175                         is_custom_class(name, dot - name, custom_variable_classes))
3176                         return add_placeholder_variable(name, elevel);
3177         }
3178
3179         /* Unknown name */
3180         return NULL;
3181 }
3182
3183
3184 /*
3185  * comparator for qsorting and bsearching guc_variables array
3186  */
3187 static int
3188 guc_var_compare(const void *a, const void *b)
3189 {
3190         struct config_generic *confa = *(struct config_generic **) a;
3191         struct config_generic *confb = *(struct config_generic **) b;
3192
3193         return guc_name_compare(confa->name, confb->name);
3194 }
3195
3196 /*
3197  * the bare comparison function for GUC names
3198  */
3199 static int
3200 guc_name_compare(const char *namea, const char *nameb)
3201 {
3202         /*
3203          * The temptation to use strcasecmp() here must be resisted, because the
3204          * array ordering has to remain stable across setlocale() calls. So, build
3205          * our own with a simple ASCII-only downcasing.
3206          */
3207         while (*namea && *nameb)
3208         {
3209                 char            cha = *namea++;
3210                 char            chb = *nameb++;
3211
3212                 if (cha >= 'A' && cha <= 'Z')
3213                         cha += 'a' - 'A';
3214                 if (chb >= 'A' && chb <= 'Z')
3215                         chb += 'a' - 'A';
3216                 if (cha != chb)
3217                         return cha - chb;
3218         }
3219         if (*namea)
3220                 return 1;                               /* a is longer */
3221         if (*nameb)
3222                 return -1;                              /* b is longer */
3223         return 0;
3224 }
3225
3226
3227 /*
3228  * Initialize GUC options during program startup.
3229  *
3230  * Note that we cannot read the config file yet, since we have not yet
3231  * processed command-line switches.
3232  */
3233 void
3234 InitializeGUCOptions(void)
3235 {
3236         int                     i;
3237         char       *env;
3238         long            stack_rlimit;
3239
3240         /*
3241          * Before log_line_prefix could possibly receive a nonempty setting, make
3242          * sure that timezone processing is minimally alive (see elog.c).
3243          */
3244         pg_timezone_pre_initialize();
3245
3246         /*
3247          * Build sorted array of all GUC variables.
3248          */
3249         build_guc_variables();
3250
3251         /*
3252          * Load all variables with their compiled-in defaults, and initialize
3253          * status fields as needed.
3254          */
3255         for (i = 0; i < num_guc_variables; i++)
3256         {
3257                 InitializeOneGUCOption(guc_variables[i]);
3258         }
3259
3260         guc_dirty = false;
3261
3262         reporting_enabled = false;
3263
3264         /*
3265          * Prevent any attempt to override the transaction modes from
3266          * non-interactive sources.
3267          */
3268         SetConfigOption("transaction_isolation", "default",
3269                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3270         SetConfigOption("transaction_read_only", "no",
3271                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3272
3273         /*
3274          * For historical reasons, some GUC parameters can receive defaults from
3275          * environment variables.  Process those settings.      NB: if you add or
3276          * remove anything here, see also ProcessConfigFile().
3277          */
3278
3279         env = getenv("PGPORT");
3280         if (env != NULL)
3281                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3282
3283         env = getenv("PGDATESTYLE");
3284         if (env != NULL)
3285                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3286
3287         env = getenv("PGCLIENTENCODING");
3288         if (env != NULL)
3289                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3290
3291         /*
3292          * rlimit isn't exactly an "environment variable", but it behaves about
3293          * the same.  If we can identify the platform stack depth rlimit, increase
3294          * default stack depth setting up to whatever is safe (but at most 2MB).
3295          */
3296         stack_rlimit = get_stack_depth_rlimit();
3297         if (stack_rlimit > 0)
3298         {
3299                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3300
3301                 if (new_limit > 100)
3302                 {
3303                         char            limbuf[16];
3304
3305                         new_limit = Min(new_limit, 2048);
3306                         sprintf(limbuf, "%d", new_limit);
3307                         SetConfigOption("max_stack_depth", limbuf,
3308                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3309                 }
3310         }
3311 }
3312
3313 /*
3314  * Initialize one GUC option variable to its compiled-in default.
3315  */
3316 static void
3317 InitializeOneGUCOption(struct config_generic * gconf)
3318 {
3319         gconf->status = 0;
3320         gconf->reset_source = PGC_S_DEFAULT;
3321         gconf->source = PGC_S_DEFAULT;
3322         gconf->stack = NULL;
3323         gconf->sourcefile = NULL;
3324         gconf->sourceline = 0;
3325
3326         switch (gconf->vartype)
3327         {
3328                 case PGC_BOOL:
3329                         {
3330                                 struct config_bool *conf = (struct config_bool *) gconf;
3331
3332                                 if (conf->assign_hook)
3333                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3334                                                                                            PGC_S_DEFAULT))
3335                                                 elog(FATAL, "failed to initialize %s to %d",
3336                                                          conf->gen.name, (int) conf->boot_val);
3337                                 *conf->variable = conf->reset_val = conf->boot_val;
3338                                 break;
3339                         }
3340                 case PGC_INT:
3341                         {
3342                                 struct config_int *conf = (struct config_int *) gconf;
3343
3344                                 Assert(conf->boot_val >= conf->min);
3345                                 Assert(conf->boot_val <= conf->max);
3346                                 if (conf->assign_hook)
3347                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3348                                                                                            PGC_S_DEFAULT))
3349                                                 elog(FATAL, "failed to initialize %s to %d",
3350                                                          conf->gen.name, conf->boot_val);
3351                                 *conf->variable = conf->reset_val = conf->boot_val;
3352                                 break;
3353                         }
3354                 case PGC_REAL:
3355                         {
3356                                 struct config_real *conf = (struct config_real *) gconf;
3357
3358                                 Assert(conf->boot_val >= conf->min);
3359                                 Assert(conf->boot_val <= conf->max);
3360                                 if (conf->assign_hook)
3361                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3362                                                                                            PGC_S_DEFAULT))
3363                                                 elog(FATAL, "failed to initialize %s to %g",
3364                                                          conf->gen.name, conf->boot_val);
3365                                 *conf->variable = conf->reset_val = conf->boot_val;
3366                                 break;
3367                         }
3368                 case PGC_STRING:
3369                         {
3370                                 struct config_string *conf = (struct config_string *) gconf;
3371                                 char       *str;
3372
3373                                 *conf->variable = NULL;
3374                                 conf->reset_val = NULL;
3375
3376                                 if (conf->boot_val == NULL)
3377                                 {
3378                                         /* leave the value NULL, do not call assign hook */
3379                                         break;
3380                                 }
3381
3382                                 str = guc_strdup(FATAL, conf->boot_val);
3383                                 conf->reset_val = str;
3384
3385                                 if (conf->assign_hook)
3386                                 {
3387                                         const char *newstr;
3388
3389                                         newstr = (*conf->assign_hook) (str, true,
3390                                                                                                    PGC_S_DEFAULT);
3391                                         if (newstr == NULL)
3392                                         {
3393                                                 elog(FATAL, "failed to initialize %s to \"%s\"",
3394                                                          conf->gen.name, str);
3395                                         }
3396                                         else if (newstr != str)
3397                                         {
3398                                                 free(str);
3399
3400                                                 /*
3401                                                  * See notes in set_config_option about casting
3402                                                  */
3403                                                 str = (char *) newstr;
3404                                                 conf->reset_val = str;
3405                                         }
3406                                 }
3407                                 *conf->variable = str;
3408                                 break;
3409                         }
3410                 case PGC_ENUM:
3411                         {
3412                                 struct config_enum *conf = (struct config_enum *) gconf;
3413
3414                                 if (conf->assign_hook)
3415                                         if (!(*conf->assign_hook) (conf->boot_val, true,
3416                                                                                            PGC_S_DEFAULT))
3417                                                 elog(FATAL, "failed to initialize %s to %s",
3418                                                          conf->gen.name,
3419                                                   config_enum_lookup_by_value(conf, conf->boot_val));
3420                                 *conf->variable = conf->reset_val = conf->boot_val;
3421                                 break;
3422                         }
3423         }
3424 }
3425
3426
3427 /*
3428  * Select the configuration files and data directory to be used, and
3429  * do the initial read of postgresql.conf.
3430  *
3431  * This is called after processing command-line switches.
3432  *              userDoption is the -D switch value if any (NULL if unspecified).
3433  *              progname is just for use in error messages.
3434  *
3435  * Returns true on success; on failure, prints a suitable error message
3436  * to stderr and returns false.
3437  */
3438 bool
3439 SelectConfigFiles(const char *userDoption, const char *progname)
3440 {
3441         char       *configdir;
3442         char       *fname;
3443         struct stat stat_buf;
3444
3445         /* configdir is -D option, or $PGDATA if no -D */
3446         if (userDoption)
3447                 configdir = make_absolute_path(userDoption);
3448         else
3449                 configdir = make_absolute_path(getenv("PGDATA"));
3450
3451         /*
3452          * Find the configuration file: if config_file was specified on the
3453          * command line, use it, else use configdir/postgresql.conf.  In any case
3454          * ensure the result is an absolute path, so that it will be interpreted
3455          * the same way by future backends.
3456          */
3457         if (ConfigFileName)
3458                 fname = make_absolute_path(ConfigFileName);
3459         else if (configdir)
3460         {
3461                 fname = guc_malloc(FATAL,
3462                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3463                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3464         }
3465         else
3466         {
3467                 write_stderr("%s does not know where to find the server configuration file.\n"
3468                                          "You must specify the --config-file or -D invocation "
3469                                          "option or set the PGDATA environment variable.\n",
3470                                          progname);
3471                 return false;
3472         }
3473
3474         /*
3475          * Set the ConfigFileName GUC variable to its final value, ensuring that
3476          * it can't be overridden later.
3477          */
3478         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3479         free(fname);
3480
3481         /*
3482          * Now read the config file for the first time.
3483          */
3484         if (stat(ConfigFileName, &stat_buf) != 0)
3485         {
3486                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3487                                          progname, ConfigFileName, strerror(errno));
3488                 return false;
3489         }
3490
3491         ProcessConfigFile(PGC_POSTMASTER);
3492
3493         /*
3494          * If the data_directory GUC variable has been set, use that as DataDir;
3495          * otherwise use configdir if set; else punt.
3496          *
3497          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3498          * have to.
3499          */
3500         if (data_directory)
3501                 SetDataDir(data_directory);
3502         else if (configdir)
3503                 SetDataDir(configdir);
3504         else
3505         {
3506                 write_stderr("%s does not know where to find the database system data.\n"
3507                                          "This can be specified as \"data_directory\" in \"%s\", "
3508                                          "or by the -D invocation option, or by the "
3509                                          "PGDATA environment variable.\n",
3510                                          progname, ConfigFileName);
3511                 return false;
3512         }
3513
3514         /*
3515          * Reflect the final DataDir value back into the data_directory GUC var.
3516          * (If you are wondering why we don't just make them a single variable,
3517          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3518          * child backends specially.  XXX is that still true?  Given that we now
3519          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3520          * DataDir in advance.)
3521          */
3522         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3523
3524         /*
3525          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3526          */
3527         if (HbaFileName)
3528                 fname = make_absolute_path(HbaFileName);
3529         else if (configdir)
3530         {
3531                 fname = guc_malloc(FATAL,
3532                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3533                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3534         }
3535         else
3536         {
3537                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3538                                          "This can be specified as \"hba_file\" in \"%s\", "
3539                                          "or by the -D invocation option, or by the "
3540                                          "PGDATA environment variable.\n",
3541                                          progname, ConfigFileName);
3542                 return false;
3543         }
3544         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3545         free(fname);
3546
3547         /*
3548          * Likewise for pg_ident.conf.
3549          */
3550         if (IdentFileName)
3551                 fname = make_absolute_path(IdentFileName);
3552         else if (configdir)
3553         {
3554                 fname = guc_malloc(FATAL,
3555                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3556                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3557         }
3558         else
3559         {
3560                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3561                                          "This can be specified as \"ident_file\" in \"%s\", "
3562                                          "or by the -D invocation option, or by the "
3563                                          "PGDATA environment variable.\n",
3564                                          progname, ConfigFileName);
3565                 return false;
3566         }
3567         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3568         free(fname);
3569
3570         free(configdir);
3571
3572         return true;
3573 }
3574
3575
3576 /*
3577  * Reset all options to their saved default values (implements RESET ALL)
3578  */
3579 void
3580 ResetAllOptions(void)
3581 {
3582         int                     i;
3583
3584         for (i = 0; i < num_guc_variables; i++)
3585         {
3586                 struct config_generic *gconf = guc_variables[i];
3587
3588                 /* Don't reset non-SET-able values */
3589                 if (gconf->context != PGC_SUSET &&
3590                         gconf->context != PGC_USERSET)
3591                         continue;
3592                 /* Don't reset if special exclusion from RESET ALL */
3593                 if (gconf->flags & GUC_NO_RESET_ALL)
3594                         continue;
3595                 /* No need to reset if wasn't SET */
3596                 if (gconf->source <= PGC_S_OVERRIDE)
3597                         continue;
3598
3599                 /* Save old value to support transaction abort */
3600                 push_old_value(gconf, GUC_ACTION_SET);
3601
3602                 switch (gconf->vartype)
3603                 {
3604                         case PGC_BOOL:
3605                                 {
3606                                         struct config_bool *conf = (struct config_bool *) gconf;
3607
3608                                         if (conf->assign_hook)
3609                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3610                                                                                                    PGC_S_SESSION))
3611                                                         elog(ERROR, "failed to reset %s to %d",
3612                                                                  conf->gen.name, (int) conf->reset_val);
3613                                         *conf->variable = conf->reset_val;
3614                                         break;
3615                                 }
3616                         case PGC_INT:
3617                                 {
3618                                         struct config_int *conf = (struct config_int *) gconf;
3619
3620                                         if (conf->assign_hook)
3621                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3622                                                                                                    PGC_S_SESSION))
3623                                                         elog(ERROR, "failed to reset %s to %d",
3624                                                                  conf->gen.name, conf->reset_val);
3625                                         *conf->variable = conf->reset_val;
3626                                         break;
3627                                 }
3628                         case PGC_REAL:
3629                                 {
3630                                         struct config_real *conf = (struct config_real *) gconf;
3631
3632                                         if (conf->assign_hook)
3633                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3634                                                                                                    PGC_S_SESSION))
3635                                                         elog(ERROR, "failed to reset %s to %g",
3636                                                                  conf->gen.name, conf->reset_val);
3637                                         *conf->variable = conf->reset_val;
3638                                         break;
3639                                 }
3640                         case PGC_STRING:
3641                                 {
3642                                         struct config_string *conf = (struct config_string *) gconf;
3643                                         char       *str;
3644
3645                                         /* We need not strdup here */
3646                                         str = conf->reset_val;
3647
3648                                         if (conf->assign_hook && str)
3649                                         {
3650                                                 const char *newstr;
3651
3652                                                 newstr = (*conf->assign_hook) (str, true,
3653                                                                                                            PGC_S_SESSION);
3654                                                 if (newstr == NULL)
3655                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3656                                                                  conf->gen.name, str);
3657                                                 else if (newstr != str)
3658                                                 {
3659                                                         /*
3660                                                          * See notes in set_config_option about casting
3661                                                          */
3662                                                         str = (char *) newstr;
3663                                                 }
3664                                         }
3665
3666                                         set_string_field(conf, conf->variable, str);
3667                                         break;
3668                                 }
3669                         case PGC_ENUM:
3670                                 {
3671                                         struct config_enum *conf = (struct config_enum *) gconf;
3672
3673                                         if (conf->assign_hook)
3674                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3675                                                                                                    PGC_S_SESSION))
3676                                                         elog(ERROR, "failed to reset %s to %s",
3677                                                                  conf->gen.name,
3678                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3679                                         *conf->variable = conf->reset_val;
3680                                         break;
3681                                 }
3682                 }
3683
3684                 gconf->source = gconf->reset_source;
3685
3686                 if (gconf->flags & GUC_REPORT)
3687                         ReportGUCOption(gconf);
3688         }
3689 }
3690
3691
3692 /*
3693  * push_old_value
3694  *              Push previous state during transactional assignment to a GUC variable.
3695  */
3696 static void
3697 push_old_value(struct config_generic * gconf, GucAction action)
3698 {
3699         GucStack   *stack;
3700
3701         /* If we're not inside a nest level, do nothing */
3702         if (GUCNestLevel == 0)
3703                 return;
3704
3705         /* Do we already have a stack entry of the current nest level? */
3706         stack = gconf->stack;
3707         if (stack && stack->nest_level >= GUCNestLevel)
3708         {
3709                 /* Yes, so adjust its state if necessary */
3710                 Assert(stack->nest_level == GUCNestLevel);
3711                 switch (action)
3712                 {
3713                         case GUC_ACTION_SET:
3714                                 /* SET overrides any prior action at same nest level */
3715                                 if (stack->state == GUC_SET_LOCAL)
3716                                 {
3717                                         /* must discard old masked value */
3718                                         discard_stack_value(gconf, &stack->masked);
3719                                 }
3720                                 stack->state = GUC_SET;
3721                                 break;
3722                         case GUC_ACTION_LOCAL:
3723                                 if (stack->state == GUC_SET)
3724                                 {
3725                                         /* SET followed by SET LOCAL, remember SET's value */
3726                                         set_stack_value(gconf, &stack->masked);
3727                                         stack->state = GUC_SET_LOCAL;
3728                                 }
3729                                 /* in all other cases, no change to stack entry */
3730                                 break;
3731                         case GUC_ACTION_SAVE:
3732                                 /* Could only have a prior SAVE of same variable */
3733                                 Assert(stack->state == GUC_SAVE);
3734                                 break;
3735                 }
3736                 Assert(guc_dirty);              /* must be set already */
3737                 return;
3738         }
3739
3740         /*
3741          * Push a new stack entry
3742          *
3743          * We keep all the stack entries in TopTransactionContext for simplicity.
3744          */
3745         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3746                                                                                                 sizeof(GucStack));
3747
3748         stack->prev = gconf->stack;
3749         stack->nest_level = GUCNestLevel;
3750         switch (action)
3751         {
3752                 case GUC_ACTION_SET:
3753                         stack->state = GUC_SET;
3754                         break;
3755                 case GUC_ACTION_LOCAL:
3756                         stack->state = GUC_LOCAL;
3757                         break;
3758                 case GUC_ACTION_SAVE:
3759                         stack->state = GUC_SAVE;
3760                         break;
3761         }
3762         stack->source = gconf->source;
3763         set_stack_value(gconf, &stack->prior);
3764
3765         gconf->stack = stack;
3766
3767         /* Ensure we remember to pop at end of xact */
3768         guc_dirty = true;
3769 }
3770
3771
3772 /*
3773  * Do GUC processing at main transaction start.
3774  */
3775 void
3776 AtStart_GUC(void)
3777 {
3778         /*
3779          * The nest level should be 0 between transactions; if it isn't, somebody
3780          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3781          * throw a warning but make no other effort to clean up.
3782          */
3783         if (GUCNestLevel != 0)
3784                 elog(WARNING, "GUC nest level = %d at transaction start",
3785                          GUCNestLevel);
3786         GUCNestLevel = 1;
3787 }
3788
3789 /*
3790  * Enter a new nesting level for GUC values.  This is called at subtransaction
3791  * start and when entering a function that has proconfig settings.      NOTE that
3792  * we must not risk error here, else subtransaction start will be unhappy.
3793  */
3794 int
3795 NewGUCNestLevel(void)
3796 {
3797         return ++GUCNestLevel;
3798 }
3799
3800 /*
3801  * Do GUC processing at transaction or subtransaction commit or abort, or
3802  * when exiting a function that has proconfig settings.  (The name is thus
3803  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3804  * During abort, we discard all GUC settings that were applied at nesting
3805  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3806  */
3807 void
3808 AtEOXact_GUC(bool isCommit, int nestLevel)
3809 {
3810         bool            still_dirty;
3811         int                     i;
3812
3813         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3814
3815         /* Quick exit if nothing's changed in this transaction */
3816         if (!guc_dirty)
3817         {
3818                 GUCNestLevel = nestLevel - 1;
3819                 return;
3820         }
3821
3822         still_dirty = false;
3823         for (i = 0; i < num_guc_variables; i++)
3824         {
3825                 struct config_generic *gconf = guc_variables[i];
3826                 GucStack   *stack;
3827
3828                 /*
3829                  * Process and pop each stack entry within the nest level.      To
3830                  * simplify fmgr_security_definer(), we allow failure exit from a
3831                  * function-with-SET-options to be recovered at the surrounding
3832                  * transaction or subtransaction abort; so there could be more than
3833                  * one stack entry to pop.
3834                  */
3835                 while ((stack = gconf->stack) != NULL &&
3836                            stack->nest_level >= nestLevel)
3837                 {
3838                         GucStack   *prev = stack->prev;
3839                         bool            restorePrior = false;
3840                         bool            restoreMasked = false;
3841                         bool            changed;
3842
3843                         /*
3844                          * In this next bit, if we don't set either restorePrior or
3845                          * restoreMasked, we must "discard" any unwanted fields of the
3846                          * stack entries to avoid leaking memory.  If we do set one of
3847                          * those flags, unused fields will be cleaned up after restoring.
3848                          */
3849                         if (!isCommit)          /* if abort, always restore prior value */
3850                                 restorePrior = true;
3851                         else if (stack->state == GUC_SAVE)
3852                                 restorePrior = true;
3853                         else if (stack->nest_level == 1)
3854                         {
3855                                 /* transaction commit */
3856                                 if (stack->state == GUC_SET_LOCAL)
3857                                         restoreMasked = true;
3858                                 else if (stack->state == GUC_SET)
3859                                 {
3860                                         /* we keep the current active value */
3861                                         discard_stack_value(gconf, &stack->prior);
3862                                 }
3863                                 else    /* must be GUC_LOCAL */
3864                                         restorePrior = true;
3865                         }
3866                         else if (prev == NULL ||
3867                                          prev->nest_level < stack->nest_level - 1)
3868                         {
3869                                 /* decrement entry's level and do not pop it */
3870                                 stack->nest_level--;
3871                                 continue;
3872                         }
3873                         else
3874                         {
3875                                 /*
3876                                  * We have to merge this stack entry into prev. See README for
3877                                  * discussion of this bit.
3878                                  */
3879                                 switch (stack->state)
3880                                 {
3881                                         case GUC_SAVE:
3882                                                 Assert(false);  /* can't get here */
3883
3884                                         case GUC_SET:
3885                                                 /* next level always becomes SET */
3886                                                 discard_stack_value(gconf, &stack->prior);
3887                                                 if (prev->state == GUC_SET_LOCAL)
3888                                                         discard_stack_value(gconf, &prev->masked);
3889                                                 prev->state = GUC_SET;
3890                                                 break;
3891
3892                                         case GUC_LOCAL:
3893                                                 if (prev->state == GUC_SET)
3894                                                 {
3895                                                         /* LOCAL migrates down */
3896                                                         prev->masked = stack->prior;
3897                                                         prev->state = GUC_SET_LOCAL;
3898                                                 }
3899                                                 else
3900                                                 {
3901                                                         /* else just forget this stack level */
3902                                                         discard_stack_value(gconf, &stack->prior);
3903                                                 }
3904                                                 break;
3905
3906                                         case GUC_SET_LOCAL:
3907                                                 /* prior state at this level no longer wanted */
3908                                                 discard_stack_value(gconf, &stack->prior);
3909                                                 /* copy down the masked state */
3910                                                 if (prev->state == GUC_SET_LOCAL)
3911                                                         discard_stack_value(gconf, &prev->masked);
3912                                                 prev->masked = stack->masked;
3913                                                 prev->state = GUC_SET_LOCAL;
3914                                                 break;
3915                                 }
3916                         }
3917
3918                         changed = false;
3919
3920                         if (restorePrior || restoreMasked)
3921                         {
3922                                 /* Perform appropriate restoration of the stacked value */
3923                                 union config_var_value newvalue;
3924                                 GucSource       newsource;
3925
3926                                 if (restoreMasked)
3927                                 {
3928                                         newvalue = stack->masked;
3929                                         newsource = PGC_S_SESSION;
3930                                 }
3931                                 else
3932                                 {
3933                                         newvalue = stack->prior;
3934                                         newsource = stack->source;
3935                                 }
3936
3937                                 switch (gconf->vartype)
3938                                 {
3939                                         case PGC_BOOL:
3940                                                 {
3941                                                         struct config_bool *conf = (struct config_bool *) gconf;
3942                                                         bool            newval = newvalue.boolval;
3943
3944                                                         if (*conf->variable != newval)
3945                                                         {
3946                                                                 if (conf->assign_hook)
3947                                                                         if (!(*conf->assign_hook) (newval,
3948                                                                                                            true, PGC_S_OVERRIDE))
3949                                                                                 elog(LOG, "failed to commit %s as %d",
3950                                                                                          conf->gen.name, (int) newval);
3951                                                                 *conf->variable = newval;
3952                                                                 changed = true;
3953                                                         }
3954                                                         break;
3955                                                 }
3956                                         case PGC_INT:
3957                                                 {
3958                                                         struct config_int *conf = (struct config_int *) gconf;
3959                                                         int                     newval = newvalue.intval;
3960
3961                                                         if (*conf->variable != newval)
3962                                                         {
3963                                                                 if (conf->assign_hook)
3964                                                                         if (!(*conf->assign_hook) (newval,
3965                                                                                                            true, PGC_S_OVERRIDE))
3966                                                                                 elog(LOG, "failed to commit %s as %d",
3967                                                                                          conf->gen.name, newval);
3968                                                                 *conf->variable = newval;
3969                                                                 changed = true;
3970                                                         }
3971                                                         break;
3972                                                 }
3973                                         case PGC_REAL:
3974                                                 {
3975                                                         struct config_real *conf = (struct config_real *) gconf;
3976                                                         double          newval = newvalue.realval;
3977
3978                                                         if (*conf->variable != newval)
3979                                                         {
3980                                                                 if (conf->assign_hook)
3981                                                                         if (!(*conf->assign_hook) (newval,
3982                                                                                                            true, PGC_S_OVERRIDE))
3983                                                                                 elog(LOG, "failed to commit %s as %g",
3984                                                                                          conf->gen.name, newval);
3985                                                                 *conf->variable = newval;
3986                                                                 changed = true;
3987                                                         }
3988                                                         break;
3989                                                 }
3990                                         case PGC_STRING:
3991                                                 {
3992                                                         struct config_string *conf = (struct config_string *) gconf;
3993                                                         char       *newval = newvalue.stringval;
3994
3995                                                         if (*conf->variable != newval)
3996                                                         {
3997                                                                 if (conf->assign_hook && newval)
3998                                                                 {
3999                                                                         const char *newstr;
4000
4001                                                                         newstr = (*conf->assign_hook) (newval, true,
4002                                                                                                                          PGC_S_OVERRIDE);
4003                                                                         if (newstr == NULL)
4004                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
4005                                                                                          conf->gen.name, newval);
4006                                                                         else if (newstr != newval)
4007                                                                         {
4008                                                                                 /*
4009                                                                                  * If newval should now be freed,
4010                                                                                  * it'll be taken care of below.
4011                                                                                  *
4012                                                                                  * See notes in set_config_option
4013                                                                                  * about casting
4014                                                                                  */
4015                                                                                 newval = (char *) newstr;
4016                                                                         }
4017                                                                 }
4018
4019                                                                 set_string_field(conf, conf->variable, newval);
4020                                                                 changed = true;
4021                                                         }
4022
4023                                                         /*
4024                                                          * Release stacked values if not used anymore. We
4025                                                          * could use discard_stack_value() here, but since
4026                                                          * we have type-specific code anyway, might as
4027                                                          * well inline it.
4028                                                          */
4029                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4030                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4031                                                         break;
4032                                                 }
4033                                         case PGC_ENUM:
4034                                                 {
4035                                                         struct config_enum *conf = (struct config_enum *) gconf;
4036                                                         int                     newval = newvalue.enumval;
4037
4038                                                         if (*conf->variable != newval)
4039                                                         {
4040                                                                 if (conf->assign_hook)
4041                                                                         if (!(*conf->assign_hook) (newval,
4042                                                                                                            true, PGC_S_OVERRIDE))
4043                                                                                 elog(LOG, "failed to commit %s as %s",
4044                                                                                          conf->gen.name,
4045                                                                                          config_enum_lookup_by_value(conf, newval));
4046                                                                 *conf->variable = newval;
4047                                                                 changed = true;
4048                                                         }
4049                                                         break;
4050                                                 }
4051                                 }
4052
4053                                 gconf->source = newsource;
4054                         }
4055
4056                         /* Finish popping the state stack */
4057                         gconf->stack = prev;
4058                         pfree(stack);
4059
4060                         /* Report new value if we changed it */
4061                         if (changed && (gconf->flags & GUC_REPORT))
4062                                 ReportGUCOption(gconf);
4063                 }                                               /* end of stack-popping loop */
4064
4065                 if (stack != NULL)
4066                         still_dirty = true;
4067         }
4068
4069         /* If there are no remaining stack entries, we can reset guc_dirty */
4070         guc_dirty = still_dirty;
4071
4072         /* Update nesting level */
4073         GUCNestLevel = nestLevel - 1;
4074 }
4075
4076
4077 /*
4078  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4079  * This is executed at completion of backend startup.
4080  */
4081 void
4082 BeginReportingGUCOptions(void)
4083 {
4084         int                     i;
4085
4086         /*
4087          * Don't do anything unless talking to an interactive frontend of protocol
4088          * 3.0 or later.
4089          */
4090         if (whereToSendOutput != DestRemote ||
4091                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4092                 return;
4093
4094         reporting_enabled = true;
4095
4096         /* Transmit initial values of interesting variables */
4097         for (i = 0; i < num_guc_variables; i++)
4098         {
4099                 struct config_generic *conf = guc_variables[i];
4100
4101                 if (conf->flags & GUC_REPORT)
4102                         ReportGUCOption(conf);
4103         }
4104 }
4105
4106 /*
4107  * ReportGUCOption: if appropriate, transmit option value to frontend
4108  */
4109 static void
4110 ReportGUCOption(struct config_generic * record)
4111 {
4112         if (reporting_enabled && (record->flags & GUC_REPORT))
4113         {
4114                 char       *val = _ShowOption(record, false);
4115                 StringInfoData msgbuf;
4116
4117                 pq_beginmessage(&msgbuf, 'S');
4118                 pq_sendstring(&msgbuf, record->name);
4119                 pq_sendstring(&msgbuf, val);
4120                 pq_endmessage(&msgbuf);
4121
4122                 pfree(val);
4123         }
4124 }
4125
4126 /*
4127  * Try to parse value as an integer.  The accepted formats are the
4128  * usual decimal, octal, or hexadecimal formats, optionally followed by
4129  * a unit name if "flags" indicates a unit is allowed.
4130  *
4131  * If the string parses okay, return true, else false.
4132  * If okay and result is not NULL, return the value in *result.
4133  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4134  *      HINT message, or NULL if no hint provided.
4135  */
4136 bool
4137 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4138 {
4139         int64           val;
4140         char       *endptr;
4141
4142         /* To suppress compiler warnings, always set output params */
4143         if (result)
4144                 *result = 0;
4145         if (hintmsg)
4146                 *hintmsg = NULL;
4147
4148         /* We assume here that int64 is at least as wide as long */
4149         errno = 0;
4150         val = strtol(value, &endptr, 0);
4151
4152         if (endptr == value)
4153                 return false;                   /* no HINT for integer syntax error */
4154
4155         if (errno == ERANGE || val != (int64) ((int32) val))
4156         {
4157                 if (hintmsg)
4158                         *hintmsg = gettext_noop("Value exceeds integer range.");
4159                 return false;
4160         }
4161
4162         /* allow whitespace between integer and unit */
4163         while (isspace((unsigned char) *endptr))
4164                 endptr++;
4165
4166         /* Handle possible unit */
4167         if (*endptr != '\0')
4168         {
4169                 /*
4170                  * Note: the multiple-switch coding technique here is a bit tedious,
4171                  * but seems necessary to avoid intermediate-value overflows.
4172                  *
4173                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4174                  * overflow due to units conversion, but there are few enough such
4175                  * machines that it does not seem worth trying to be smarter.
4176                  */
4177                 if (flags & GUC_UNIT_MEMORY)
4178                 {
4179                         /* Set hint for use if no match or trailing garbage */
4180                         if (hintmsg)
4181                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4182
4183 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4184 #error BLCKSZ must be between 1KB and 1MB
4185 #endif
4186 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4187 #error XLOG_BLCKSZ must be between 1KB and 1MB
4188 #endif
4189
4190                         if (strncmp(endptr, "kB", 2) == 0)
4191                         {
4192                                 endptr += 2;
4193                                 switch (flags & GUC_UNIT_MEMORY)
4194                                 {
4195                                         case GUC_UNIT_BLOCKS:
4196                                                 val /= (BLCKSZ / 1024);
4197                                                 break;
4198                                         case GUC_UNIT_XBLOCKS:
4199                                                 val /= (XLOG_BLCKSZ / 1024);
4200                                                 break;
4201                                 }
4202                         }
4203                         else if (strncmp(endptr, "MB", 2) == 0)
4204                         {
4205                                 endptr += 2;
4206                                 switch (flags & GUC_UNIT_MEMORY)
4207                                 {
4208                                         case GUC_UNIT_KB:
4209                                                 val *= KB_PER_MB;
4210                                                 break;
4211                                         case GUC_UNIT_BLOCKS:
4212                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4213                                                 break;
4214                                         case GUC_UNIT_XBLOCKS:
4215                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4216                                                 break;
4217                                 }
4218                         }
4219                         else if (strncmp(endptr, "GB", 2) == 0)
4220                         {
4221                                 endptr += 2;
4222                                 switch (flags & GUC_UNIT_MEMORY)
4223                                 {
4224                                         case GUC_UNIT_KB:
4225                                                 val *= KB_PER_GB;
4226                                                 break;
4227                                         case GUC_UNIT_BLOCKS:
4228                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4229                                                 break;
4230                                         case GUC_UNIT_XBLOCKS:
4231                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4232                                                 break;
4233                                 }
4234                         }
4235                 }
4236                 else if (flags & GUC_UNIT_TIME)
4237                 {
4238                         /* Set hint for use if no match or trailing garbage */
4239                         if (hintmsg)
4240                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4241
4242                         if (strncmp(endptr, "ms", 2) == 0)
4243                         {
4244                                 endptr += 2;
4245                                 switch (flags & GUC_UNIT_TIME)
4246                                 {
4247                                         case GUC_UNIT_S:
4248                                                 val /= MS_PER_S;
4249                                                 break;
4250                                         case GUC_UNIT_MIN:
4251                                                 val /= MS_PER_MIN;
4252                                                 break;
4253                                 }
4254                         }
4255                         else if (strncmp(endptr, "s", 1) == 0)
4256                         {
4257                                 endptr += 1;
4258                                 switch (flags & GUC_UNIT_TIME)
4259                                 {
4260                                         case GUC_UNIT_MS:
4261                                                 val *= MS_PER_S;
4262                                                 break;
4263                                         case GUC_UNIT_MIN:
4264                                                 val /= S_PER_MIN;
4265                                                 break;
4266                                 }
4267                         }
4268                         else if (strncmp(endptr, "min", 3) == 0)
4269                         {
4270                                 endptr += 3;
4271                                 switch (flags & GUC_UNIT_TIME)
4272                                 {
4273                                         case GUC_UNIT_MS:
4274                                                 val *= MS_PER_MIN;
4275                                                 break;
4276                                         case GUC_UNIT_S:
4277                                                 val *= S_PER_MIN;
4278                                                 break;
4279                                 }
4280                         }
4281                         else if (strncmp(endptr, "h", 1) == 0)
4282                         {
4283                                 endptr += 1;
4284                                 switch (flags & GUC_UNIT_TIME)
4285                                 {
4286                                         case GUC_UNIT_MS:
4287                                                 val *= MS_PER_H;
4288                                                 break;
4289                                         case GUC_UNIT_S:
4290                                                 val *= S_PER_H;
4291                                                 break;
4292                                         case GUC_UNIT_MIN:
4293                                                 val *= MIN_PER_H;
4294                                                 break;
4295                                 }
4296                         }
4297                         else if (strncmp(endptr, "d", 1) == 0)
4298                         {
4299                                 endptr += 1;
4300                                 switch (flags & GUC_UNIT_TIME)
4301                                 {
4302                                         case GUC_UNIT_MS:
4303                                                 val *= MS_PER_D;
4304                                                 break;
4305                                         case GUC_UNIT_S:
4306                                                 val *= S_PER_D;
4307                                                 break;
4308                                         case GUC_UNIT_MIN:
4309                                                 val *= MIN_PER_D;
4310                                                 break;
4311                                 }
4312                         }
4313                 }
4314
4315                 /* allow whitespace after unit */
4316                 while (isspace((unsigned char) *endptr))
4317                         endptr++;
4318
4319                 if (*endptr != '\0')
4320                         return false;           /* appropriate hint, if any, already set */
4321
4322                 /* Check for overflow due to units conversion */
4323                 if (val != (int64) ((int32) val))
4324                 {
4325                         if (hintmsg)
4326                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4327                         return false;
4328                 }
4329         }
4330
4331         if (result)
4332                 *result = (int) val;
4333         return true;
4334 }
4335
4336
4337
4338 /*
4339  * Try to parse value as a floating point number in the usual format.
4340  * If the string parses okay, return true, else false.
4341  * If okay and result is not NULL, return the value in *result.
4342  */
4343 bool
4344 parse_real(const char *value, double *result)
4345 {
4346         double          val;
4347         char       *endptr;
4348
4349         if (result)
4350                 *result = 0;                    /* suppress compiler warning */
4351
4352         errno = 0;
4353         val = strtod(value, &endptr);
4354         if (endptr == value || errno == ERANGE)
4355                 return false;
4356
4357         /* allow whitespace after number */
4358         while (isspace((unsigned char) *endptr))
4359                 endptr++;
4360         if (*endptr != '\0')
4361                 return false;
4362
4363         if (result)
4364                 *result = val;
4365         return true;
4366 }
4367
4368
4369 /*
4370  * Lookup the name for an enum option with the selected value.
4371  * Should only ever be called with known-valid values, so throws
4372  * an elog(ERROR) if the enum option is not found.
4373  *
4374  * The returned string is a pointer to static data and not
4375  * allocated for modification.
4376  */
4377 const char *
4378 config_enum_lookup_by_value(struct config_enum * record, int val)
4379 {
4380         const struct config_enum_entry *entry;
4381
4382         for (entry = record->options; entry && entry->name; entry++)
4383         {
4384                 if (entry->val == val)
4385                         return entry->name;
4386         }
4387
4388         elog(ERROR, "could not find enum option %d for %s",
4389                  val, record->gen.name);
4390         return NULL;                            /* silence compiler */
4391 }
4392
4393
4394 /*
4395  * Lookup the value for an enum option with the selected name
4396  * (case-insensitive).
4397  * If the enum option is found, sets the retval value and returns
4398  * true. If it's not found, return FALSE and retval is set to 0.
4399  */
4400 bool
4401 config_enum_lookup_by_name(struct config_enum * record, const char *value,
4402                                                    int *retval)
4403 {
4404         const struct config_enum_entry *entry;
4405
4406         for (entry = record->options; entry && entry->name; entry++)
4407         {
4408                 if (pg_strcasecmp(value, entry->name) == 0)
4409                 {
4410                         *retval = entry->val;
4411                         return TRUE;
4412                 }
4413         }
4414
4415         *retval = 0;
4416         return FALSE;
4417 }
4418
4419
4420 /*
4421  * Return a list of all available options for an enum, excluding
4422  * hidden ones, separated by the given separator.
4423  * If prefix is non-NULL, it is added before the first enum value.
4424  * If suffix is non-NULL, it is added to the end of the string.
4425  */
4426 static char *
4427 config_enum_get_options(struct config_enum * record, const char *prefix,
4428                                                 const char *suffix, const char *separator)
4429 {
4430         const struct config_enum_entry *entry;
4431         StringInfoData retstr;
4432         int                     seplen;
4433
4434         initStringInfo(&retstr);
4435         appendStringInfoString(&retstr, prefix);
4436
4437         seplen = strlen(separator);
4438         for (entry = record->options; entry && entry->name; entry++)
4439         {
4440                 if (!entry->hidden)
4441                 {
4442                         appendStringInfoString(&retstr, entry->name);
4443                         appendBinaryStringInfo(&retstr, separator, seplen);
4444                 }
4445         }
4446
4447         /*
4448          * All the entries may have been hidden, leaving the string empty if no
4449          * prefix was given. This indicates a broken GUC setup, since there is no
4450          * use for an enum without any values, so we just check to make sure we
4451          * don't write to invalid memory instead of actually trying to do
4452          * something smart with it.
4453          */
4454         if (retstr.len >= seplen)
4455         {
4456                 /* Replace final separator */
4457                 retstr.data[retstr.len - seplen] = '\0';
4458                 retstr.len -= seplen;
4459         }
4460
4461         appendStringInfoString(&retstr, suffix);
4462
4463         return retstr.data;
4464 }
4465
4466 /*
4467  * Call a GucStringAssignHook function, being careful to free the
4468  * "newval" string if the hook ereports.
4469  *
4470  * This is split out of set_config_option just to avoid the "volatile"
4471  * qualifiers that would otherwise have to be plastered all over.
4472  */
4473 static const char *
4474 call_string_assign_hook(GucStringAssignHook assign_hook,
4475                                                 char *newval, bool doit, GucSource source)
4476 {
4477         const char *result;
4478
4479         PG_TRY();
4480         {
4481                 result = (*assign_hook) (newval, doit, source);
4482         }
4483         PG_CATCH();
4484         {
4485                 free(newval);
4486                 PG_RE_THROW();
4487         }
4488         PG_END_TRY();
4489
4490         return result;
4491 }
4492
4493
4494 /*
4495  * Sets option `name' to given value. The value should be a string
4496  * which is going to be parsed and converted to the appropriate data
4497  * type.  The context and source parameters indicate in which context this
4498  * function is being called so it can apply the access restrictions
4499  * properly.
4500  *
4501  * If value is NULL, set the option to its default value (normally the
4502  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4503  *
4504  * action indicates whether to set the value globally in the session, locally
4505  * to the current top transaction, or just for the duration of a function call.
4506  *
4507  * If changeVal is false then don't really set the option but do all
4508  * the checks to see if it would work.
4509  *
4510  * If there is an error (non-existing option, invalid value) then an
4511  * ereport(ERROR) is thrown *unless* this is called in a context where we
4512  * don't want to ereport (currently, startup or SIGHUP config file reread).
4513  * In that case we write a suitable error message via ereport(LOG) and
4514  * return false. This is working around the deficiencies in the ereport
4515  * mechanism, so don't blame me.  In all other cases, the function
4516  * returns true, including cases where the input is valid but we chose
4517  * not to apply it because of context or source-priority considerations.
4518  *
4519  * See also SetConfigOption for an external interface.
4520  */
4521 bool
4522 set_config_option(const char *name, const char *value,
4523                                   GucContext context, GucSource source,
4524                                   GucAction action, bool changeVal)
4525 {
4526         struct config_generic *record;
4527         int                     elevel;
4528         bool            makeDefault;
4529
4530         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4531         {
4532                 /*
4533                  * To avoid cluttering the log, only the postmaster bleats loudly
4534                  * about problems with the config file.
4535                  */
4536                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4537         }
4538         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4539                 elevel = WARNING;
4540         else
4541                 elevel = ERROR;
4542
4543         record = find_option(name, true, elevel);
4544         if (record == NULL)
4545         {
4546                 ereport(elevel,
4547                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4548                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4549                 return false;
4550         }
4551
4552         /*
4553          * If source is postgresql.conf, mark the found record with
4554          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4555          * that we do it even if changeVal is false, since ProcessConfigFile wants
4556          * the marking to occur during its testing pass.
4557          */
4558         if (source == PGC_S_FILE)
4559                 record->status |= GUC_IS_IN_FILE;
4560
4561         /*
4562          * Check if the option can be set at this time. See guc.h for the precise
4563          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4564          * context. In that case we just ignore the attempt and return true.
4565          */
4566         switch (record->context)
4567         {
4568                 case PGC_INTERNAL:
4569                         if (context == PGC_SIGHUP)
4570                                 return true;
4571                         if (context != PGC_INTERNAL)
4572                         {
4573                                 ereport(elevel,
4574                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4575                                                  errmsg("parameter \"%s\" cannot be changed",
4576                                                                 name)));
4577                                 return false;
4578                         }
4579                         break;
4580                 case PGC_POSTMASTER:
4581                         if (context == PGC_SIGHUP)
4582                         {
4583                                 /*
4584                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4585                                  * We can't change the setting, so give a warning if the DBA
4586                                  * tries to change it.  (Throwing an error would be more
4587                                  * consistent, but seems overly rigid.)
4588                                  */
4589                                 if (changeVal && !is_newvalue_equal(record, value))
4590                                         ereport(elevel,
4591                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4592                                            errmsg("attempted change of parameter \"%s\" ignored",
4593                                                           name),
4594                                                          errdetail("This parameter cannot be changed after server start.")));
4595                                 return true;
4596                         }
4597                         if (context != PGC_POSTMASTER)
4598                         {
4599                                 ereport(elevel,
4600                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4601                                            errmsg("attempted change of parameter \"%s\" ignored",
4602                                                           name),
4603                                                  errdetail("This parameter cannot be changed after server start.")));
4604                                 return false;
4605                         }
4606                         break;
4607                 case PGC_SIGHUP:
4608                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4609                         {
4610                                 ereport(elevel,
4611                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4612                                                  errmsg("parameter \"%s\" cannot be changed now",
4613                                                                 name)));
4614                                 return false;
4615                         }
4616
4617                         /*
4618                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4619                          * can be changed after postmaster start". But there's nothing
4620                          * that prevents a crafty administrator from sending SIGHUP
4621                          * signals to individual backends only.
4622                          */
4623                         break;
4624                 case PGC_BACKEND:
4625                         if (context == PGC_SIGHUP)
4626                         {
4627                                 /*
4628                                  * If a PGC_BACKEND parameter is changed in the config file,
4629                                  * we want to accept the new value in the postmaster (whence
4630                                  * it will propagate to subsequently-started backends), but
4631                                  * ignore it in existing backends.      This is a tad klugy, but
4632                                  * necessary because we don't re-read the config file during
4633                                  * backend start.
4634                                  */
4635                                 if (IsUnderPostmaster)
4636                                         return true;
4637                         }
4638                         else if (context != PGC_POSTMASTER && context != PGC_BACKEND &&
4639                                          source != PGC_S_CLIENT)
4640                         {
4641                                 ereport(elevel,
4642                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4643                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4644                                                                 name)));
4645                                 return false;
4646                         }
4647                         break;
4648                 case PGC_SUSET:
4649                         if (context == PGC_USERSET || context == PGC_BACKEND)
4650                         {
4651                                 ereport(elevel,
4652                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4653                                                  errmsg("permission denied to set parameter \"%s\"",
4654                                                                 name)));
4655                                 return false;
4656                         }
4657                         break;
4658                 case PGC_USERSET:
4659                         /* always okay */
4660                         break;
4661         }
4662
4663         /*
4664          * Should we set reset/stacked values?  (If so, the behavior is not
4665          * transactional.)      This is done either when we get a default value from
4666          * the database's/user's/client's default settings or when we reset a
4667          * value to its default.
4668          */
4669         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4670                 ((value != NULL) || source == PGC_S_DEFAULT);
4671
4672         /*
4673          * Ignore attempted set if overridden by previously processed setting.
4674          * However, if changeVal is false then plow ahead anyway since we are
4675          * trying to find out if the value is potentially good, not actually use
4676          * it. Also keep going if makeDefault is true, since we may want to set
4677          * the reset/stacked values even if we can't set the variable itself.
4678          */
4679         if (record->source > source)
4680         {
4681                 if (changeVal && !makeDefault)
4682                 {
4683                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4684                                  name);
4685                         return true;
4686                 }
4687                 changeVal = false;
4688         }
4689
4690         /*
4691          * Evaluate value and set variable.
4692          */
4693         switch (record->vartype)
4694         {
4695                 case PGC_BOOL:
4696                         {
4697                                 struct config_bool *conf = (struct config_bool *) record;
4698                                 bool            newval;
4699
4700                                 if (value)
4701                                 {
4702                                         if (!parse_bool(value, &newval))
4703                                         {
4704                                                 ereport(elevel,
4705                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4706                                                   errmsg("parameter \"%s\" requires a Boolean value",
4707                                                                  name)));
4708                                                 return false;
4709                                         }
4710                                 }
4711                                 else if (source == PGC_S_DEFAULT)
4712                                         newval = conf->boot_val;
4713                                 else
4714                                 {
4715                                         newval = conf->reset_val;
4716                                         source = conf->gen.reset_source;
4717                                 }
4718
4719                                 /* Save old value to support transaction abort */
4720                                 if (changeVal && !makeDefault)
4721                                         push_old_value(&conf->gen, action);
4722
4723                                 if (conf->assign_hook)
4724                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4725                                         {
4726                                                 ereport(elevel,
4727                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4728                                                          errmsg("invalid value for parameter \"%s\": %d",
4729                                                                         name, (int) newval)));
4730                                                 return false;
4731                                         }
4732
4733                                 if (changeVal)
4734                                 {
4735                                         *conf->variable = newval;
4736                                         conf->gen.source = source;
4737                                 }
4738                                 if (makeDefault)
4739                                 {
4740                                         GucStack   *stack;
4741
4742                                         if (conf->gen.reset_source <= source)
4743                                         {
4744                                                 conf->reset_val = newval;
4745                                                 conf->gen.reset_source = source;
4746                                         }
4747                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4748                                         {
4749                                                 if (stack->source <= source)
4750                                                 {
4751                                                         stack->prior.boolval = newval;
4752                                                         stack->source = source;
4753                                                 }
4754                                         }
4755                                 }
4756                                 break;
4757                         }
4758
4759                 case PGC_INT:
4760                         {
4761                                 struct config_int *conf = (struct config_int *) record;
4762                                 int                     newval;
4763
4764                                 if (value)
4765                                 {
4766                                         const char *hintmsg;
4767
4768                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4769                                         {
4770                                                 ereport(elevel,
4771                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4772                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4773                                                                 name, value),
4774                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4775                                                 return false;
4776                                         }
4777                                         if (newval < conf->min || newval > conf->max)
4778                                         {
4779                                                 ereport(elevel,
4780                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4781                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4782                                                                                 newval, name, conf->min, conf->max)));
4783                                                 return false;
4784                                         }
4785                                 }
4786                                 else if (source == PGC_S_DEFAULT)
4787                                         newval = conf->boot_val;
4788                                 else
4789                                 {
4790                                         newval = conf->reset_val;
4791                                         source = conf->gen.reset_source;
4792                                 }
4793
4794                                 /* Save old value to support transaction abort */
4795                                 if (changeVal && !makeDefault)
4796                                         push_old_value(&conf->gen, action);
4797
4798                                 if (conf->assign_hook)
4799                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4800                                         {
4801                                                 ereport(elevel,
4802                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4803                                                          errmsg("invalid value for parameter \"%s\": %d",
4804                                                                         name, newval)));
4805                                                 return false;
4806                                         }
4807
4808                                 if (changeVal)
4809                                 {
4810                                         *conf->variable = newval;
4811                                         conf->gen.source = source;
4812                                 }
4813                                 if (makeDefault)
4814                                 {
4815                                         GucStack   *stack;
4816
4817                                         if (conf->gen.reset_source <= source)
4818                                         {
4819                                                 conf->reset_val = newval;
4820                                                 conf->gen.reset_source = source;
4821                                         }
4822                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4823                                         {
4824                                                 if (stack->source <= source)
4825                                                 {
4826                                                         stack->prior.intval = newval;
4827                                                         stack->source = source;
4828                                                 }
4829                                         }
4830                                 }
4831                                 break;
4832                         }
4833
4834                 case PGC_REAL:
4835                         {
4836                                 struct config_real *conf = (struct config_real *) record;
4837                                 double          newval;
4838
4839                                 if (value)
4840                                 {
4841                                         if (!parse_real(value, &newval))
4842                                         {
4843                                                 ereport(elevel,
4844                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4845                                                   errmsg("parameter \"%s\" requires a numeric value",
4846                                                                  name)));
4847                                                 return false;
4848                                         }
4849                                         if (newval < conf->min || newval > conf->max)
4850                                         {
4851                                                 ereport(elevel,
4852                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4853                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4854                                                                                 newval, name, conf->min, conf->max)));
4855                                                 return false;
4856                                         }
4857                                 }
4858                                 else if (source == PGC_S_DEFAULT)
4859                                         newval = conf->boot_val;
4860                                 else
4861                                 {
4862                                         newval = conf->reset_val;
4863                                         source = conf->gen.reset_source;
4864                                 }
4865
4866                                 /* Save old value to support transaction abort */
4867                                 if (changeVal && !makeDefault)
4868                                         push_old_value(&conf->gen, action);
4869
4870                                 if (conf->assign_hook)
4871                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4872                                         {
4873                                                 ereport(elevel,
4874                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4875                                                          errmsg("invalid value for parameter \"%s\": %g",
4876                                                                         name, newval)));
4877                                                 return false;
4878                                         }
4879
4880                                 if (changeVal)
4881                                 {
4882                                         *conf->variable = newval;
4883                                         conf->gen.source = source;
4884                                 }
4885                                 if (makeDefault)
4886                                 {
4887                                         GucStack   *stack;
4888
4889                                         if (conf->gen.reset_source <= source)
4890                                         {
4891                                                 conf->reset_val = newval;
4892                                                 conf->gen.reset_source = source;
4893                                         }
4894                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4895                                         {
4896                                                 if (stack->source <= source)
4897                                                 {
4898                                                         stack->prior.realval = newval;
4899                                                         stack->source = source;
4900                                                 }
4901                                         }
4902                                 }
4903                                 break;
4904                         }
4905
4906                 case PGC_STRING:
4907                         {
4908                                 struct config_string *conf = (struct config_string *) record;
4909                                 char       *newval;
4910
4911                                 if (value)
4912                                 {
4913                                         newval = guc_strdup(elevel, value);
4914                                         if (newval == NULL)
4915                                                 return false;
4916
4917                                         /*
4918                                          * The only sort of "parsing" check we need to do is apply
4919                                          * truncation if GUC_IS_NAME.
4920                                          */
4921                                         if (conf->gen.flags & GUC_IS_NAME)
4922                                                 truncate_identifier(newval, strlen(newval), true);
4923                                 }
4924                                 else if (source == PGC_S_DEFAULT)
4925                                 {
4926                                         if (conf->boot_val == NULL)
4927                                                 newval = NULL;
4928                                         else
4929                                         {
4930                                                 newval = guc_strdup(elevel, conf->boot_val);
4931                                                 if (newval == NULL)
4932                                                         return false;
4933                                         }
4934                                 }
4935                                 else
4936                                 {
4937                                         /*
4938                                          * We could possibly avoid strdup here, but easier to make
4939                                          * this case work the same as the normal assignment case;
4940                                          * note the possible free of newval below.
4941                                          */
4942                                         if (conf->reset_val == NULL)
4943                                                 newval = NULL;
4944                                         else
4945                                         {
4946                                                 newval = guc_strdup(elevel, conf->reset_val);
4947                                                 if (newval == NULL)
4948                                                         return false;
4949                                         }
4950                                         source = conf->gen.reset_source;
4951                                 }
4952
4953                                 /* Save old value to support transaction abort */
4954                                 if (changeVal && !makeDefault)
4955                                         push_old_value(&conf->gen, action);
4956
4957                                 if (conf->assign_hook && newval)
4958                                 {
4959                                         const char *hookresult;
4960
4961                                         /*
4962                                          * If the hook ereports, we have to make sure we free
4963                                          * newval, else it will be a permanent memory leak.
4964                                          */
4965                                         hookresult = call_string_assign_hook(conf->assign_hook,
4966                                                                                                                  newval,
4967                                                                                                                  changeVal,
4968                                                                                                                  source);
4969                                         if (hookresult == NULL)
4970                                         {
4971                                                 free(newval);
4972                                                 ereport(elevel,
4973                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4974                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4975                                                                 name, value ? value : "")));
4976                                                 return false;
4977                                         }
4978                                         else if (hookresult != newval)
4979                                         {
4980                                                 free(newval);
4981
4982                                                 /*
4983                                                  * Having to cast away const here is annoying, but the
4984                                                  * alternative is to declare assign_hooks as returning
4985                                                  * char*, which would mean they'd have to cast away
4986                                                  * const, or as both taking and returning char*, which
4987                                                  * doesn't seem attractive either --- we don't want
4988                                                  * them to scribble on the passed str.
4989                                                  */
4990                                                 newval = (char *) hookresult;
4991                                         }
4992                                 }
4993
4994                                 if (changeVal)
4995                                 {
4996                                         set_string_field(conf, conf->variable, newval);
4997                                         conf->gen.source = source;
4998                                 }
4999                                 if (makeDefault)
5000                                 {
5001                                         GucStack   *stack;
5002
5003                                         if (conf->gen.reset_source <= source)
5004                                         {
5005                                                 set_string_field(conf, &conf->reset_val, newval);
5006                                                 conf->gen.reset_source = source;
5007                                         }
5008                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5009                                         {
5010                                                 if (stack->source <= source)
5011                                                 {
5012                                                         set_string_field(conf, &stack->prior.stringval,
5013                                                                                          newval);
5014                                                         stack->source = source;
5015                                                 }
5016                                         }
5017                                 }
5018                                 /* Perhaps we didn't install newval anywhere */
5019                                 if (newval && !string_field_used(conf, newval))
5020                                         free(newval);
5021                                 break;
5022                         }
5023                 case PGC_ENUM:
5024                         {
5025                                 struct config_enum *conf = (struct config_enum *) record;
5026                                 int                     newval;
5027
5028                                 if (value)
5029                                 {
5030                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5031                                         {
5032                                                 char       *hintmsg;
5033
5034                                                 hintmsg = config_enum_get_options(conf,
5035                                                                                                                 "Available values: ",
5036                                                                                                                   ".", ", ");
5037
5038                                                 ereport(elevel,
5039                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5040                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5041                                                                 name, value),
5042                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5043
5044                                                 if (hintmsg)
5045                                                         pfree(hintmsg);
5046                                                 return false;
5047                                         }
5048                                 }
5049                                 else if (source == PGC_S_DEFAULT)
5050                                         newval = conf->boot_val;
5051                                 else
5052                                 {
5053                                         newval = conf->reset_val;
5054                                         source = conf->gen.reset_source;
5055                                 }
5056
5057                                 /* Save old value to support transaction abort */
5058                                 if (changeVal && !makeDefault)
5059                                         push_old_value(&conf->gen, action);
5060
5061                                 if (conf->assign_hook)
5062                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5063                                         {
5064                                                 ereport(elevel,
5065                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5066                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5067                                                                 name,
5068                                                                 config_enum_lookup_by_value(conf, newval))));
5069                                                 return false;
5070                                         }
5071
5072                                 if (changeVal)
5073                                 {
5074                                         *conf->variable = newval;
5075                                         conf->gen.source = source;
5076                                 }
5077                                 if (makeDefault)
5078                                 {
5079                                         GucStack   *stack;
5080
5081                                         if (conf->gen.reset_source <= source)
5082                                         {
5083                                                 conf->reset_val = newval;
5084                                                 conf->gen.reset_source = source;
5085                                         }
5086                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5087                                         {
5088                                                 if (stack->source <= source)
5089                                                 {
5090                                                         stack->prior.enumval = newval;
5091                                                         stack->source = source;
5092                                                 }
5093                                         }
5094                                 }
5095                                 break;
5096                         }
5097         }
5098
5099         if (changeVal && (record->flags & GUC_REPORT))
5100                 ReportGUCOption(record);
5101
5102         return true;
5103 }
5104
5105
5106 /*
5107  * Set the fields for source file and line number the setting came from.
5108  */
5109 static void
5110 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5111 {
5112         struct config_generic *record;
5113         int                     elevel;
5114
5115         /*
5116          * To avoid cluttering the log, only the postmaster bleats loudly about
5117          * problems with the config file.
5118          */
5119         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5120
5121         record = find_option(name, true, elevel);
5122         /* should not happen */
5123         if (record == NULL)
5124                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5125
5126         sourcefile = guc_strdup(elevel, sourcefile);
5127         if (record->sourcefile)
5128                 free(record->sourcefile);
5129         record->sourcefile = sourcefile;
5130         record->sourceline = sourceline;
5131 }
5132
5133 /*
5134  * Set a config option to the given value. See also set_config_option,
5135  * this is just the wrapper to be called from outside GUC.      NB: this
5136  * is used only for non-transactional operations.
5137  *
5138  * Note: there is no support here for setting source file/line, as it
5139  * is currently not needed.
5140  */
5141 void
5142 SetConfigOption(const char *name, const char *value,
5143                                 GucContext context, GucSource source)
5144 {
5145         (void) set_config_option(name, value, context, source,
5146                                                          GUC_ACTION_SET, true);
5147 }
5148
5149
5150
5151 /*
5152  * Fetch the current value of the option `name'. If the option doesn't exist,
5153  * throw an ereport and don't return.
5154  *
5155  * The string is *not* allocated for modification and is really only
5156  * valid until the next call to configuration related functions.
5157  */
5158 const char *
5159 GetConfigOption(const char *name)
5160 {
5161         struct config_generic *record;
5162         static char buffer[256];
5163
5164         record = find_option(name, false, ERROR);
5165         if (record == NULL)
5166                 ereport(ERROR,
5167                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5168                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5169         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5170                 ereport(ERROR,
5171                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5172                                  errmsg("must be superuser to examine \"%s\"", name)));
5173
5174         switch (record->vartype)
5175         {
5176                 case PGC_BOOL:
5177                         return *((struct config_bool *) record)->variable ? "on" : "off";
5178
5179                 case PGC_INT:
5180                         snprintf(buffer, sizeof(buffer), "%d",
5181                                          *((struct config_int *) record)->variable);
5182                         return buffer;
5183
5184                 case PGC_REAL:
5185                         snprintf(buffer, sizeof(buffer), "%g",
5186                                          *((struct config_real *) record)->variable);
5187                         return buffer;
5188
5189                 case PGC_STRING:
5190                         return *((struct config_string *) record)->variable;
5191
5192                 case PGC_ENUM:
5193                         return config_enum_lookup_by_value((struct config_enum *) record,
5194                                                                  *((struct config_enum *) record)->variable);
5195         }
5196         return NULL;
5197 }
5198
5199 /*
5200  * Get the RESET value associated with the given option.
5201  *
5202  * Note: this is not re-entrant, due to use of static result buffer;
5203  * not to mention that a string variable could have its reset_val changed.
5204  * Beware of assuming the result value is good for very long.
5205  */
5206 const char *
5207 GetConfigOptionResetString(const char *name)
5208 {
5209         struct config_generic *record;
5210         static char buffer[256];
5211
5212         record = find_option(name, false, ERROR);
5213         if (record == NULL)
5214                 ereport(ERROR,
5215                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5216                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5217         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5218                 ereport(ERROR,
5219                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5220                                  errmsg("must be superuser to examine \"%s\"", name)));
5221
5222         switch (record->vartype)
5223         {
5224                 case PGC_BOOL:
5225                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5226
5227                 case PGC_INT:
5228                         snprintf(buffer, sizeof(buffer), "%d",
5229                                          ((struct config_int *) record)->reset_val);
5230                         return buffer;
5231
5232                 case PGC_REAL:
5233                         snprintf(buffer, sizeof(buffer), "%g",
5234                                          ((struct config_real *) record)->reset_val);
5235                         return buffer;
5236
5237                 case PGC_STRING:
5238                         return ((struct config_string *) record)->reset_val;
5239
5240                 case PGC_ENUM:
5241                         return config_enum_lookup_by_value((struct config_enum *) record,
5242                                                                  ((struct config_enum *) record)->reset_val);
5243         }
5244         return NULL;
5245 }
5246
5247
5248 /*
5249  * GUC_complaint_elevel
5250  *              Get the ereport error level to use in an assign_hook's error report.
5251  *
5252  * This should be used by assign hooks that want to emit a custom error
5253  * report (in addition to the generic "invalid value for option FOO" that
5254  * guc.c will provide).  Note that the result might be ERROR or a lower
5255  * level, so the caller must be prepared for control to return from ereport,
5256  * or not.      If control does return, return false/NULL from the hook function.
5257  *
5258  * At some point it'd be nice to replace this with a mechanism that allows
5259  * the custom message to become the DETAIL line of guc.c's generic message.
5260  */
5261 int
5262 GUC_complaint_elevel(GucSource source)
5263 {
5264         int                     elevel;
5265
5266         if (source == PGC_S_FILE)
5267         {
5268                 /*
5269                  * To avoid cluttering the log, only the postmaster bleats loudly
5270                  * about problems with the config file.
5271                  */
5272                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5273         }
5274         else if (source == PGC_S_OVERRIDE)
5275         {
5276                 /*
5277                  * If we're a postmaster child, this is probably "undo" during
5278                  * transaction abort, so we don't want to clutter the log.  There's a
5279                  * small chance of a real problem with an OVERRIDE setting, though, so
5280                  * suppressing the message entirely wouldn't be desirable.
5281                  */
5282                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5283         }
5284         else if (source < PGC_S_INTERACTIVE)
5285                 elevel = LOG;
5286         else
5287                 elevel = ERROR;
5288
5289         return elevel;
5290 }
5291
5292
5293 /*
5294  * flatten_set_variable_args
5295  *              Given a parsenode List as emitted by the grammar for SET,
5296  *              convert to the flat string representation used by GUC.
5297  *
5298  * We need to be told the name of the variable the args are for, because
5299  * the flattening rules vary (ugh).
5300  *
5301  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5302  * a palloc'd string.
5303  */
5304 static char *
5305 flatten_set_variable_args(const char *name, List *args)
5306 {
5307         struct config_generic *record;
5308         int                     flags;
5309         StringInfoData buf;
5310         ListCell   *l;
5311
5312         /* Fast path if just DEFAULT */
5313         if (args == NIL)
5314                 return NULL;
5315
5316         /* Else get flags for the variable */
5317         record = find_option(name, true, ERROR);
5318         if (record == NULL)
5319                 ereport(ERROR,
5320                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5321                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5322
5323         flags = record->flags;
5324
5325         /* Complain if list input and non-list variable */
5326         if ((flags & GUC_LIST_INPUT) == 0 &&
5327                 list_length(args) != 1)
5328                 ereport(ERROR,
5329                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5330                                  errmsg("SET %s takes only one argument", name)));
5331
5332         initStringInfo(&buf);
5333
5334         /*
5335          * Each list member may be a plain A_Const node, or an A_Const within a
5336          * TypeCast; the latter case is supported only for ConstInterval arguments
5337          * (for SET TIME ZONE).
5338          */
5339         foreach(l, args)
5340         {
5341                 Node       *arg = (Node *) lfirst(l);
5342                 char       *val;
5343                 TypeName   *typeName = NULL;
5344                 A_Const    *con;
5345
5346                 if (l != list_head(args))
5347                         appendStringInfo(&buf, ", ");
5348
5349                 if (IsA(arg, TypeCast))
5350                 {
5351                         TypeCast   *tc = (TypeCast *) arg;
5352
5353                         arg = tc->arg;
5354                         typeName = tc->typeName;
5355                 }
5356
5357                 if (!IsA(arg, A_Const))
5358                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5359                 con = (A_Const *) arg;
5360
5361                 switch (nodeTag(&con->val))
5362                 {
5363                         case T_Integer:
5364                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5365                                 break;
5366                         case T_Float:
5367                                 /* represented as a string, so just copy it */
5368                                 appendStringInfoString(&buf, strVal(&con->val));
5369                                 break;
5370                         case T_String:
5371                                 val = strVal(&con->val);
5372                                 if (typeName != NULL)
5373                                 {
5374                                         /*
5375                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5376                                          * to interval and back to normalize the value and account
5377                                          * for any typmod.
5378                                          */
5379                                         Oid                     typoid;
5380                                         int32           typmod;
5381                                         Datum           interval;
5382                                         char       *intervalout;
5383
5384                                         typoid = typenameTypeId(NULL, typeName, &typmod);
5385                                         Assert(typoid == INTERVALOID);
5386
5387                                         interval =
5388                                                 DirectFunctionCall3(interval_in,
5389                                                                                         CStringGetDatum(val),
5390                                                                                         ObjectIdGetDatum(InvalidOid),
5391                                                                                         Int32GetDatum(typmod));
5392
5393                                         intervalout =
5394                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5395                                                                                                                         interval));
5396                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5397                                 }
5398                                 else
5399                                 {
5400                                         /*
5401                                          * Plain string literal or identifier.  For quote mode,
5402                                          * quote it if it's not a vanilla identifier.
5403                                          */
5404                                         if (flags & GUC_LIST_QUOTE)
5405                                                 appendStringInfoString(&buf, quote_identifier(val));
5406                                         else
5407                                                 appendStringInfoString(&buf, val);
5408                                 }
5409                                 break;
5410                         default:
5411                                 elog(ERROR, "unrecognized node type: %d",
5412                                          (int) nodeTag(&con->val));
5413                                 break;
5414                 }
5415         }
5416
5417         return buf.data;
5418 }
5419
5420
5421 /*
5422  * SET command
5423  */
5424 void
5425 ExecSetVariableStmt(VariableSetStmt *stmt)
5426 {
5427         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5428
5429         switch (stmt->kind)
5430         {
5431                 case VAR_SET_VALUE:
5432                 case VAR_SET_CURRENT:
5433                         set_config_option(stmt->name,
5434                                                           ExtractSetVariableArgs(stmt),
5435                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5436                                                           PGC_S_SESSION,
5437                                                           action,
5438                                                           true);
5439                         break;
5440                 case VAR_SET_MULTI:
5441
5442                         /*
5443                          * Special case for special SQL syntax that effectively sets more
5444                          * than one variable per statement.
5445                          */
5446                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5447                         {
5448                                 ListCell   *head;
5449
5450                                 foreach(head, stmt->args)
5451                                 {
5452                                         DefElem    *item = (DefElem *) lfirst(head);
5453
5454                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5455                                                 SetPGVariable("transaction_isolation",
5456                                                                           list_make1(item->arg), stmt->is_local);
5457                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5458                                                 SetPGVariable("transaction_read_only",
5459                                                                           list_make1(item->arg), stmt->is_local);
5460                                         else
5461                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5462                                                          item->defname);
5463                                 }
5464                         }
5465                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5466                         {
5467                                 ListCell   *head;
5468
5469                                 foreach(head, stmt->args)
5470                                 {
5471                                         DefElem    *item = (DefElem *) lfirst(head);
5472
5473                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5474                                                 SetPGVariable("default_transaction_isolation",
5475                                                                           list_make1(item->arg), stmt->is_local);
5476                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5477                                                 SetPGVariable("default_transaction_read_only",
5478                                                                           list_make1(item->arg), stmt->is_local);
5479                                         else
5480                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5481                                                          item->defname);
5482                                 }
5483                         }
5484                         else
5485                                 elog(ERROR, "unexpected SET MULTI element: %s",
5486                                          stmt->name);
5487                         break;
5488                 case VAR_SET_DEFAULT:
5489                 case VAR_RESET:
5490                         set_config_option(stmt->name,
5491                                                           NULL,
5492                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5493                                                           PGC_S_SESSION,
5494                                                           action,
5495                                                           true);
5496                         break;
5497                 case VAR_RESET_ALL:
5498                         ResetAllOptions();
5499                         break;
5500         }
5501 }
5502
5503 /*
5504  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5505  * The result is palloc'd.
5506  *
5507  * This is exported for use by actions such as ALTER ROLE SET.
5508  */
5509 char *
5510 ExtractSetVariableArgs(VariableSetStmt *stmt)
5511 {
5512         switch (stmt->kind)
5513         {
5514                 case VAR_SET_VALUE:
5515                         return flatten_set_variable_args(stmt->name, stmt->args);
5516                 case VAR_SET_CURRENT:
5517                         return GetConfigOptionByName(stmt->name, NULL);
5518                 default:
5519                         return NULL;
5520         }
5521 }
5522
5523 /*
5524  * SetPGVariable - SET command exported as an easily-C-callable function.
5525  *
5526  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5527  * by passing args == NIL), but not SET FROM CURRENT functionality.
5528  */
5529 void
5530 SetPGVariable(const char *name, List *args, bool is_local)
5531 {
5532         char       *argstring = flatten_set_variable_args(name, args);
5533
5534         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5535         set_config_option(name,
5536                                           argstring,
5537                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5538                                           PGC_S_SESSION,
5539                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5540                                           true);
5541 }
5542
5543 /*
5544  * SET command wrapped as a SQL callable function.
5545  */
5546 Datum
5547 set_config_by_name(PG_FUNCTION_ARGS)
5548 {
5549         char       *name;
5550         char       *value;
5551         char       *new_value;
5552         bool            is_local;
5553
5554         if (PG_ARGISNULL(0))
5555                 ereport(ERROR,
5556                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5557                                  errmsg("SET requires parameter name")));
5558
5559         /* Get the GUC variable name */
5560         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5561
5562         /* Get the desired value or set to NULL for a reset request */
5563         if (PG_ARGISNULL(1))
5564                 value = NULL;
5565         else
5566                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5567
5568         /*
5569          * Get the desired state of is_local. Default to false if provided value
5570          * is NULL
5571          */
5572         if (PG_ARGISNULL(2))
5573                 is_local = false;
5574         else
5575                 is_local = PG_GETARG_BOOL(2);
5576
5577         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5578         set_config_option(name,
5579                                           value,
5580                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5581                                           PGC_S_SESSION,
5582                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5583                                           true);
5584
5585         /* get the new current value */
5586         new_value = GetConfigOptionByName(name, NULL);
5587
5588         /* Convert return string to text */
5589         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5590 }
5591
5592
5593 /*
5594  * Common code for DefineCustomXXXVariable subroutines: allocate the
5595  * new variable's config struct and fill in generic fields.
5596  */
5597 static struct config_generic *
5598 init_custom_variable(const char *name,
5599                                          const char *short_desc,
5600                                          const char *long_desc,
5601                                          GucContext context,
5602                                          int flags,
5603                                          enum config_type type,
5604                                          size_t sz)
5605 {
5606         struct config_generic *gen;
5607
5608         /*
5609          * Only allow custom PGC_POSTMASTER variables to be created during shared
5610          * library preload; any later than that, we can't ensure that the value
5611          * doesn't change after startup.  This is a fatal elog if it happens; just
5612          * erroring out isn't safe because we don't know what the calling loadable
5613          * module might already have hooked into.
5614          */
5615         if (context == PGC_POSTMASTER &&
5616                 !process_shared_preload_libraries_in_progress)
5617                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5618
5619         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5620         memset(gen, 0, sz);
5621
5622         gen->name = guc_strdup(ERROR, name);
5623         gen->context = context;
5624         gen->group = CUSTOM_OPTIONS;
5625         gen->short_desc = short_desc;
5626         gen->long_desc = long_desc;
5627         gen->flags = flags;
5628         gen->vartype = type;
5629
5630         return gen;
5631 }
5632
5633 /*
5634  * Common code for DefineCustomXXXVariable subroutines: insert the new
5635  * variable into the GUC variable array, replacing any placeholder.
5636  */
5637 static void
5638 define_custom_variable(struct config_generic * variable)
5639 {
5640         const char *name = variable->name;
5641         const char **nameAddr = &name;
5642         const char *value;
5643         struct config_string *pHolder;
5644         GucContext      phcontext;
5645         struct config_generic **res;
5646
5647         /*
5648          * See if there's a placeholder by the same name.
5649          */
5650         res = (struct config_generic **) bsearch((void *) &nameAddr,
5651                                                                                          (void *) guc_variables,
5652                                                                                          num_guc_variables,
5653                                                                                          sizeof(struct config_generic *),
5654                                                                                          guc_var_compare);
5655         if (res == NULL)
5656         {
5657                 /*
5658                  * No placeholder to replace, so we can just add it ... but first,
5659                  * make sure it's initialized to its default value.
5660                  */
5661                 InitializeOneGUCOption(variable);
5662                 add_guc_variable(variable, ERROR);
5663                 return;
5664         }
5665
5666         /*
5667          * This better be a placeholder
5668          */
5669         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5670                 ereport(ERROR,
5671                                 (errcode(ERRCODE_INTERNAL_ERROR),
5672                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5673
5674         Assert((*res)->vartype == PGC_STRING);
5675         pHolder = (struct config_string *) (*res);
5676
5677         /*
5678          * First, set the variable to its default value.  We must do this even
5679          * though we intend to immediately apply a new value, since it's possible
5680          * that the new value is invalid.
5681          */
5682         InitializeOneGUCOption(variable);
5683
5684         /*
5685          * Replace the placeholder. We aren't changing the name, so no re-sorting
5686          * is necessary
5687          */
5688         *res = variable;
5689
5690         /*
5691          * Infer context for assignment based on source of existing value. We
5692          * can't tell this with exact accuracy, but we can at least do something
5693          * reasonable in typical cases.
5694          */
5695         switch (pHolder->gen.source)
5696         {
5697                 case PGC_S_DEFAULT:
5698                 case PGC_S_ENV_VAR:
5699                 case PGC_S_FILE:
5700                 case PGC_S_ARGV:
5701
5702                         /*
5703                          * If we got past the check in init_custom_variable, we can safely
5704                          * assume that any existing value for a PGC_POSTMASTER variable
5705                          * was set in postmaster context.
5706                          */
5707                         if (variable->context == PGC_POSTMASTER)
5708                                 phcontext = PGC_POSTMASTER;
5709                         else
5710                                 phcontext = PGC_SIGHUP;
5711                         break;
5712                 case PGC_S_DATABASE:
5713                 case PGC_S_USER:
5714                 case PGC_S_CLIENT:
5715                 case PGC_S_SESSION:
5716                 default:
5717                         phcontext = PGC_USERSET;
5718                         break;
5719         }
5720
5721         /*
5722          * Assign the string value stored in the placeholder to the real variable.
5723          *
5724          * XXX this is not really good enough --- it should be a nontransactional
5725          * assignment, since we don't want it to roll back if the current xact
5726          * fails later.  (Or do we?)
5727          */
5728         value = *pHolder->variable;
5729
5730         if (value)
5731         {
5732                 if (set_config_option(name, value,
5733                                                           phcontext, pHolder->gen.source,
5734                                                           GUC_ACTION_SET, true))
5735                 {
5736                         /* Also copy over any saved source-location information */
5737                         if (pHolder->gen.sourcefile)
5738                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5739                                                                           pHolder->gen.sourceline);
5740                 }
5741         }
5742
5743         /*
5744          * Free up as much as we conveniently can of the placeholder structure
5745          * (this neglects any stack items...)
5746          */
5747         set_string_field(pHolder, pHolder->variable, NULL);
5748         set_string_field(pHolder, &pHolder->reset_val, NULL);
5749
5750         free(pHolder);
5751 }
5752
5753 void
5754 DefineCustomBoolVariable(const char *name,
5755                                                  const char *short_desc,
5756                                                  const char *long_desc,
5757                                                  bool *valueAddr,
5758                                                  bool bootValue,
5759                                                  GucContext context,
5760                                                  int flags,
5761                                                  GucBoolAssignHook assign_hook,
5762                                                  GucShowHook show_hook)
5763 {
5764         struct config_bool *var;
5765
5766         var = (struct config_bool *)
5767                 init_custom_variable(name, short_desc, long_desc, context, flags,
5768                                                          PGC_BOOL, sizeof(struct config_bool));
5769         var->variable = valueAddr;
5770         var->boot_val = bootValue;
5771         var->reset_val = bootValue;
5772         var->assign_hook = assign_hook;
5773         var->show_hook = show_hook;
5774         define_custom_variable(&var->gen);
5775 }
5776
5777 void
5778 DefineCustomIntVariable(const char *name,
5779                                                 const char *short_desc,
5780                                                 const char *long_desc,
5781                                                 int *valueAddr,
5782                                                 int bootValue,
5783                                                 int minValue,
5784                                                 int maxValue,
5785                                                 GucContext context,
5786                                                 int flags,
5787                                                 GucIntAssignHook assign_hook,
5788                                                 GucShowHook show_hook)
5789 {
5790         struct config_int *var;
5791
5792         var = (struct config_int *)
5793                 init_custom_variable(name, short_desc, long_desc, context, flags,
5794                                                          PGC_INT, sizeof(struct config_int));
5795         var->variable = valueAddr;
5796         var->boot_val = bootValue;
5797         var->reset_val = bootValue;
5798         var->min = minValue;
5799         var->max = maxValue;
5800         var->assign_hook = assign_hook;
5801         var->show_hook = show_hook;
5802         define_custom_variable(&var->gen);
5803 }
5804
5805 void
5806 DefineCustomRealVariable(const char *name,
5807                                                  const char *short_desc,
5808                                                  const char *long_desc,
5809                                                  double *valueAddr,
5810                                                  double bootValue,
5811                                                  double minValue,
5812                                                  double maxValue,
5813                                                  GucContext context,
5814                                                  int flags,
5815                                                  GucRealAssignHook assign_hook,
5816                                                  GucShowHook show_hook)
5817 {
5818         struct config_real *var;
5819
5820         var = (struct config_real *)
5821                 init_custom_variable(name, short_desc, long_desc, context, flags,
5822                                                          PGC_REAL, sizeof(struct config_real));
5823         var->variable = valueAddr;
5824         var->boot_val = bootValue;
5825         var->reset_val = bootValue;
5826         var->min = minValue;
5827         var->max = maxValue;
5828         var->assign_hook = assign_hook;
5829         var->show_hook = show_hook;
5830         define_custom_variable(&var->gen);
5831 }
5832
5833 void
5834 DefineCustomStringVariable(const char *name,
5835                                                    const char *short_desc,
5836                                                    const char *long_desc,
5837                                                    char **valueAddr,
5838                                                    const char *bootValue,
5839                                                    GucContext context,
5840                                                    int flags,
5841                                                    GucStringAssignHook assign_hook,
5842                                                    GucShowHook show_hook)
5843 {
5844         struct config_string *var;
5845
5846         var = (struct config_string *)
5847                 init_custom_variable(name, short_desc, long_desc, context, flags,
5848                                                          PGC_STRING, sizeof(struct config_string));
5849         var->variable = valueAddr;
5850         var->boot_val = bootValue;
5851         /* we could probably do without strdup, but keep it like normal case */
5852         if (var->boot_val)
5853                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5854         var->assign_hook = assign_hook;
5855         var->show_hook = show_hook;
5856         define_custom_variable(&var->gen);
5857 }
5858
5859 void
5860 DefineCustomEnumVariable(const char *name,
5861                                                  const char *short_desc,
5862                                                  const char *long_desc,
5863                                                  int *valueAddr,
5864                                                  int bootValue,
5865                                                  const struct config_enum_entry * options,
5866                                                  GucContext context,
5867                                                  int flags,
5868                                                  GucEnumAssignHook assign_hook,
5869                                                  GucShowHook show_hook)
5870 {
5871         struct config_enum *var;
5872
5873         var = (struct config_enum *)
5874                 init_custom_variable(name, short_desc, long_desc, context, flags,
5875                                                          PGC_ENUM, sizeof(struct config_enum));
5876         var->variable = valueAddr;
5877         var->boot_val = bootValue;
5878         var->reset_val = bootValue;
5879         var->options = options;
5880         var->assign_hook = assign_hook;
5881         var->show_hook = show_hook;
5882         define_custom_variable(&var->gen);
5883 }
5884
5885 void
5886 EmitWarningsOnPlaceholders(const char *className)
5887 {
5888         int                     classLen = strlen(className);
5889         int                     i;
5890
5891         for (i = 0; i < num_guc_variables; i++)
5892         {
5893                 struct config_generic *var = guc_variables[i];
5894
5895                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5896                         strncmp(className, var->name, classLen) == 0 &&
5897                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5898                 {
5899                         ereport(WARNING,
5900                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5901                                          errmsg("unrecognized configuration parameter \"%s\"",
5902                                                         var->name)));
5903                 }
5904         }
5905 }
5906
5907
5908 /*
5909  * SHOW command
5910  */
5911 void
5912 GetPGVariable(const char *name, DestReceiver *dest)
5913 {
5914         if (guc_name_compare(name, "all") == 0)
5915                 ShowAllGUCConfig(dest);
5916         else
5917                 ShowGUCConfigOption(name, dest);
5918 }
5919
5920 TupleDesc
5921 GetPGVariableResultDesc(const char *name)
5922 {
5923         TupleDesc       tupdesc;
5924
5925         if (guc_name_compare(name, "all") == 0)
5926         {
5927                 /* need a tuple descriptor representing three TEXT columns */
5928                 tupdesc = CreateTemplateTupleDesc(3, false);
5929                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5930                                                    TEXTOID, -1, 0);
5931                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5932                                                    TEXTOID, -1, 0);
5933                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5934                                                    TEXTOID, -1, 0);
5935         }
5936         else
5937         {
5938                 const char *varname;
5939
5940                 /* Get the canonical spelling of name */
5941                 (void) GetConfigOptionByName(name, &varname);
5942
5943                 /* need a tuple descriptor representing a single TEXT column */
5944                 tupdesc = CreateTemplateTupleDesc(1, false);
5945                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5946                                                    TEXTOID, -1, 0);
5947         }
5948         return tupdesc;
5949 }
5950
5951
5952 /*
5953  * SHOW command
5954  */
5955 static void
5956 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5957 {
5958         TupOutputState *tstate;
5959         TupleDesc       tupdesc;
5960         const char *varname;
5961         char       *value;
5962
5963         /* Get the value and canonical spelling of name */
5964         value = GetConfigOptionByName(name, &varname);
5965
5966         /* need a tuple descriptor representing a single TEXT column */
5967         tupdesc = CreateTemplateTupleDesc(1, false);
5968         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5969                                            TEXTOID, -1, 0);
5970
5971         /* prepare for projection of tuples */
5972         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5973
5974         /* Send it */
5975         do_text_output_oneline(tstate, value);
5976
5977         end_tup_output(tstate);
5978 }
5979
5980 /*
5981  * SHOW ALL command
5982  */
5983 static void
5984 ShowAllGUCConfig(DestReceiver *dest)
5985 {
5986         bool            am_superuser = superuser();
5987         int                     i;
5988         TupOutputState *tstate;
5989         TupleDesc       tupdesc;
5990         Datum       values[3];
5991         bool            isnull[3] = { false, false, false };
5992
5993         /* need a tuple descriptor representing three TEXT columns */
5994         tupdesc = CreateTemplateTupleDesc(3, false);
5995         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5996                                            TEXTOID, -1, 0);
5997         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5998                                            TEXTOID, -1, 0);
5999         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6000                                            TEXTOID, -1, 0);
6001
6002         /* prepare for projection of tuples */
6003         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6004
6005         for (i = 0; i < num_guc_variables; i++)
6006         {
6007                 struct config_generic *conf = guc_variables[i];
6008                 char   *setting;
6009
6010                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6011                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6012                         continue;
6013
6014                 /* assign to the values array */
6015                 values[0] = PointerGetDatum(cstring_to_text(conf->name));
6016
6017                 setting = _ShowOption(conf, true);
6018                 if (setting)
6019                 {
6020                         values[1] = PointerGetDatum(cstring_to_text(setting));
6021                         isnull[1] = false;
6022                 }
6023                 else
6024                 {
6025                         values[1] = PointerGetDatum(NULL);
6026                         isnull[1] = true;
6027                 }
6028
6029                 values[2] = PointerGetDatum(cstring_to_text(conf->short_desc));
6030
6031                 /* send it to dest */
6032                 do_tup_output(tstate, values, isnull);
6033
6034                 /* clean up */
6035                 pfree(DatumGetPointer(values[0]));
6036                 if (setting)
6037                 {
6038                         pfree(setting);
6039                         pfree(DatumGetPointer(values[1]));
6040                 }
6041                 pfree(DatumGetPointer(values[2]));
6042         }
6043
6044         end_tup_output(tstate);
6045 }
6046
6047 /*
6048  * Return GUC variable value by name; optionally return canonical
6049  * form of name.  Return value is palloc'd.
6050  */
6051 char *
6052 GetConfigOptionByName(const char *name, const char **varname)
6053 {
6054         struct config_generic *record;
6055
6056         record = find_option(name, false, ERROR);
6057         if (record == NULL)
6058                 ereport(ERROR,
6059                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6060                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6061         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6062                 ereport(ERROR,
6063                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6064                                  errmsg("must be superuser to examine \"%s\"", name)));
6065
6066         if (varname)
6067                 *varname = record->name;
6068
6069         return _ShowOption(record, true);
6070 }
6071
6072 /*
6073  * Return GUC variable value by variable number; optionally return canonical
6074  * form of name.  Return value is palloc'd.
6075  */
6076 void
6077 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6078 {
6079         char            buffer[256];
6080         struct config_generic *conf;
6081
6082         /* check requested variable number valid */
6083         Assert((varnum >= 0) && (varnum < num_guc_variables));
6084
6085         conf = guc_variables[varnum];
6086
6087         if (noshow)
6088         {
6089                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6090                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6091                         *noshow = true;
6092                 else
6093                         *noshow = false;
6094         }
6095
6096         /* first get the generic attributes */
6097
6098         /* name */
6099         values[0] = conf->name;
6100
6101         /* setting : use _ShowOption in order to avoid duplicating the logic */
6102         values[1] = _ShowOption(conf, false);
6103
6104         /* unit */
6105         if (conf->vartype == PGC_INT)
6106         {
6107                 static char buf[8];
6108
6109                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6110                 {
6111                         case GUC_UNIT_KB:
6112                                 values[2] = "kB";
6113                                 break;
6114                         case GUC_UNIT_BLOCKS:
6115                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6116                                 values[2] = buf;
6117                                 break;
6118                         case GUC_UNIT_XBLOCKS:
6119                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6120                                 values[2] = buf;
6121                                 break;
6122                         case GUC_UNIT_MS:
6123                                 values[2] = "ms";
6124                                 break;
6125                         case GUC_UNIT_S:
6126                                 values[2] = "s";
6127                                 break;
6128                         case GUC_UNIT_MIN:
6129                                 values[2] = "min";
6130                                 break;
6131                         default:
6132                                 values[2] = "";
6133                                 break;
6134                 }
6135         }
6136         else
6137                 values[2] = NULL;
6138
6139         /* group */
6140         values[3] = config_group_names[conf->group];
6141
6142         /* short_desc */
6143         values[4] = conf->short_desc;
6144
6145         /* extra_desc */
6146         values[5] = conf->long_desc;
6147
6148         /* context */
6149         values[6] = GucContext_Names[conf->context];
6150
6151         /* vartype */
6152         values[7] = config_type_names[conf->vartype];
6153
6154         /* source */
6155         values[8] = GucSource_Names[conf->source];
6156
6157         /* now get the type specifc attributes */
6158         switch (conf->vartype)
6159         {
6160                 case PGC_BOOL:
6161                         {
6162                                 struct config_bool *lconf = (struct config_bool *) conf;
6163
6164                                 /* min_val */
6165                                 values[9] = NULL;
6166
6167                                 /* max_val */
6168                                 values[10] = NULL;
6169
6170                                 /* enumvals */
6171                                 values[11] = NULL;
6172
6173                                 /* boot_val */
6174                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6175
6176                                 /* reset_val */
6177                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6178                         }
6179                         break;
6180
6181                 case PGC_INT:
6182                         {
6183                                 struct config_int *lconf = (struct config_int *) conf;
6184
6185                                 /* min_val */
6186                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6187                                 values[9] = pstrdup(buffer);
6188
6189                                 /* max_val */
6190                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6191                                 values[10] = pstrdup(buffer);
6192
6193                                 /* enumvals */
6194                                 values[11] = NULL;
6195
6196                                 /* boot_val */
6197                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6198                                 values[12] = pstrdup(buffer);
6199
6200                                 /* reset_val */
6201                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6202                                 values[13] = pstrdup(buffer);
6203                         }
6204                         break;
6205
6206                 case PGC_REAL:
6207                         {
6208                                 struct config_real *lconf = (struct config_real *) conf;
6209
6210                                 /* min_val */
6211                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6212                                 values[9] = pstrdup(buffer);
6213
6214                                 /* max_val */
6215                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6216                                 values[10] = pstrdup(buffer);
6217
6218                                 /* enumvals */
6219                                 values[11] = NULL;
6220
6221                                 /* boot_val */
6222                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6223                                 values[12] = pstrdup(buffer);
6224
6225                                 /* reset_val */
6226                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6227                                 values[13] = pstrdup(buffer);
6228                         }
6229                         break;
6230
6231                 case PGC_STRING:
6232                         {
6233                                 struct config_string *lconf = (struct config_string *) conf;
6234
6235                                 /* min_val */
6236                                 values[9] = NULL;
6237
6238                                 /* max_val */
6239                                 values[10] = NULL;
6240
6241                                 /* enumvals */
6242                                 values[11] = NULL;
6243
6244                                 /* boot_val */
6245                                 if (lconf->boot_val == NULL)
6246                                         values[12] = NULL;
6247                                 else
6248                                         values[12] = pstrdup(lconf->boot_val);
6249
6250                                 /* reset_val */
6251                                 if (lconf->reset_val == NULL)
6252                                         values[13] = NULL;
6253                                 else
6254                                         values[13] = pstrdup(lconf->reset_val);
6255                         }
6256                         break;
6257
6258                 case PGC_ENUM:
6259                         {
6260                                 struct config_enum *lconf = (struct config_enum *) conf;
6261
6262                                 /* min_val */
6263                                 values[9] = NULL;
6264
6265                                 /* max_val */
6266                                 values[10] = NULL;
6267
6268                                 /* enumvals */
6269
6270                                 /*
6271                                  * NOTE! enumvals with double quotes in them are not
6272                                  * supported!
6273                                  */
6274                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6275                                                                                                          "{\"", "\"}", "\",\"");
6276
6277                                 /* boot_val */
6278                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6279                                                                                                                    lconf->boot_val));
6280
6281                                 /* reset_val */
6282                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6283                                                                                                                   lconf->reset_val));
6284                         }
6285                         break;
6286
6287                 default:
6288                         {
6289                                 /*
6290                                  * should never get here, but in case we do, set 'em to NULL
6291                                  */
6292
6293                                 /* min_val */
6294                                 values[9] = NULL;
6295
6296                                 /* max_val */
6297                                 values[10] = NULL;
6298
6299                                 /* enumvals */
6300                                 values[11] = NULL;
6301
6302                                 /* boot_val */
6303                                 values[12] = NULL;
6304
6305                                 /* reset_val */
6306                                 values[13] = NULL;
6307                         }
6308                         break;
6309         }
6310
6311         /*
6312          * If the setting came from a config file, set the source location. For
6313          * security reasons, we don't show source file/line number for
6314          * non-superusers.
6315          */
6316         if (conf->source == PGC_S_FILE && superuser())
6317         {
6318                 values[14] = conf->sourcefile;
6319                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6320                 values[15] = pstrdup(buffer);
6321         }
6322         else
6323         {
6324                 values[14] = NULL;
6325                 values[15] = NULL;
6326         }
6327 }
6328
6329 /*
6330  * Return the total number of GUC variables
6331  */
6332 int
6333 GetNumConfigOptions(void)
6334 {
6335         return num_guc_variables;
6336 }
6337
6338 /*
6339  * show_config_by_name - equiv to SHOW X command but implemented as
6340  * a function.
6341  */
6342 Datum
6343 show_config_by_name(PG_FUNCTION_ARGS)
6344 {
6345         char       *varname;
6346         char       *varval;
6347
6348         /* Get the GUC variable name */
6349         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6350
6351         /* Get the value */
6352         varval = GetConfigOptionByName(varname, NULL);
6353
6354         /* Convert to text */
6355         PG_RETURN_TEXT_P(cstring_to_text(varval));
6356 }
6357
6358 /*
6359  * show_all_settings - equiv to SHOW ALL command but implemented as
6360  * a Table Function.
6361  */
6362 #define NUM_PG_SETTINGS_ATTS    16
6363
6364 Datum
6365 show_all_settings(PG_FUNCTION_ARGS)
6366 {
6367         FuncCallContext *funcctx;
6368         TupleDesc       tupdesc;
6369         int                     call_cntr;
6370         int                     max_calls;
6371         AttInMetadata *attinmeta;
6372         MemoryContext oldcontext;
6373
6374         /* stuff done only on the first call of the function */
6375         if (SRF_IS_FIRSTCALL())
6376         {
6377                 /* create a function context for cross-call persistence */
6378                 funcctx = SRF_FIRSTCALL_INIT();
6379
6380                 /*
6381                  * switch to memory context appropriate for multiple function calls
6382                  */
6383                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6384
6385                 /*
6386                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6387                  * of the appropriate types
6388                  */
6389                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6390                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6391                                                    TEXTOID, -1, 0);
6392                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6393                                                    TEXTOID, -1, 0);
6394                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6395                                                    TEXTOID, -1, 0);
6396                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6397                                                    TEXTOID, -1, 0);
6398                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6399                                                    TEXTOID, -1, 0);
6400                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6401                                                    TEXTOID, -1, 0);
6402                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6403                                                    TEXTOID, -1, 0);
6404                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6405                                                    TEXTOID, -1, 0);
6406                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6407                                                    TEXTOID, -1, 0);
6408                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6409                                                    TEXTOID, -1, 0);
6410                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6411                                                    TEXTOID, -1, 0);
6412                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6413                                                    TEXTARRAYOID, -1, 0);
6414                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6415                                                    TEXTOID, -1, 0);
6416                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6417                                                    TEXTOID, -1, 0);
6418                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6419                                                    TEXTOID, -1, 0);
6420                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6421                                                    INT4OID, -1, 0);
6422
6423                 /*
6424                  * Generate attribute metadata needed later to produce tuples from raw
6425                  * C strings
6426                  */
6427                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6428                 funcctx->attinmeta = attinmeta;
6429
6430                 /* total number of tuples to be returned */
6431                 funcctx->max_calls = GetNumConfigOptions();
6432
6433                 MemoryContextSwitchTo(oldcontext);
6434         }
6435
6436         /* stuff done on every call of the function */
6437         funcctx = SRF_PERCALL_SETUP();
6438
6439         call_cntr = funcctx->call_cntr;
6440         max_calls = funcctx->max_calls;
6441         attinmeta = funcctx->attinmeta;
6442
6443         if (call_cntr < max_calls)      /* do when there is more left to send */
6444         {
6445                 char       *values[NUM_PG_SETTINGS_ATTS];
6446                 bool            noshow;
6447                 HeapTuple       tuple;
6448                 Datum           result;
6449
6450                 /*
6451                  * Get the next visible GUC variable name and value
6452                  */
6453                 do
6454                 {
6455                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6456                         if (noshow)
6457                         {
6458                                 /* bump the counter and get the next config setting */
6459                                 call_cntr = ++funcctx->call_cntr;
6460
6461                                 /* make sure we haven't gone too far now */
6462                                 if (call_cntr >= max_calls)
6463                                         SRF_RETURN_DONE(funcctx);
6464                         }
6465                 } while (noshow);
6466
6467                 /* build a tuple */
6468                 tuple = BuildTupleFromCStrings(attinmeta, values);
6469
6470                 /* make the tuple into a datum */
6471                 result = HeapTupleGetDatum(tuple);
6472
6473                 SRF_RETURN_NEXT(funcctx, result);
6474         }
6475         else
6476         {
6477                 /* do when there is no more left */
6478                 SRF_RETURN_DONE(funcctx);
6479         }
6480 }
6481
6482 static char *
6483 _ShowOption(struct config_generic * record, bool use_units)
6484 {
6485         char            buffer[256];
6486         const char *val;
6487
6488         switch (record->vartype)
6489         {
6490                 case PGC_BOOL:
6491                         {
6492                                 struct config_bool *conf = (struct config_bool *) record;
6493
6494                                 if (conf->show_hook)
6495                                         val = (*conf->show_hook) ();
6496                                 else
6497                                         val = *conf->variable ? "on" : "off";
6498                         }
6499                         break;
6500
6501                 case PGC_INT:
6502                         {
6503                                 struct config_int *conf = (struct config_int *) record;
6504
6505                                 if (conf->show_hook)
6506                                         val = (*conf->show_hook) ();
6507                                 else
6508                                 {
6509                                         /*
6510                                          * Use int64 arithmetic to avoid overflows in units
6511                                          * conversion.  If INT64_IS_BUSTED we might overflow
6512                                          * anyway and print bogus answers, but there are few
6513                                          * enough such machines that it doesn't seem worth trying
6514                                          * harder.
6515                                          */
6516                                         int64           result = *conf->variable;
6517                                         const char *unit;
6518
6519                                         if (use_units && result > 0 &&
6520                                                 (record->flags & GUC_UNIT_MEMORY))
6521                                         {
6522                                                 switch (record->flags & GUC_UNIT_MEMORY)
6523                                                 {
6524                                                         case GUC_UNIT_BLOCKS:
6525                                                                 result *= BLCKSZ / 1024;
6526                                                                 break;
6527                                                         case GUC_UNIT_XBLOCKS:
6528                                                                 result *= XLOG_BLCKSZ / 1024;
6529                                                                 break;
6530                                                 }
6531
6532                                                 if (result % KB_PER_GB == 0)
6533                                                 {
6534                                                         result /= KB_PER_GB;
6535                                                         unit = "GB";
6536                                                 }
6537                                                 else if (result % KB_PER_MB == 0)
6538                                                 {
6539                                                         result /= KB_PER_MB;
6540                                                         unit = "MB";
6541                                                 }
6542                                                 else
6543                                                 {
6544                                                         unit = "kB";
6545                                                 }
6546                                         }
6547                                         else if (use_units && result > 0 &&
6548                                                          (record->flags & GUC_UNIT_TIME))
6549                                         {
6550                                                 switch (record->flags & GUC_UNIT_TIME)
6551                                                 {
6552                                                         case GUC_UNIT_S:
6553                                                                 result *= MS_PER_S;
6554                                                                 break;
6555                                                         case GUC_UNIT_MIN:
6556                                                                 result *= MS_PER_MIN;
6557                                                                 break;
6558                                                 }
6559
6560                                                 if (result % MS_PER_D == 0)
6561                                                 {
6562                                                         result /= MS_PER_D;
6563                                                         unit = "d";
6564                                                 }
6565                                                 else if (result % MS_PER_H == 0)
6566                                                 {
6567                                                         result /= MS_PER_H;
6568                                                         unit = "h";
6569                                                 }
6570                                                 else if (result % MS_PER_MIN == 0)
6571                                                 {
6572                                                         result /= MS_PER_MIN;
6573                                                         unit = "min";
6574                                                 }
6575                                                 else if (result % MS_PER_S == 0)
6576                                                 {
6577                                                         result /= MS_PER_S;
6578                                                         unit = "s";
6579                                                 }
6580                                                 else
6581                                                 {
6582                                                         unit = "ms";
6583                                                 }
6584                                         }
6585                                         else
6586                                                 unit = "";
6587
6588                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6589                                                          result, unit);
6590                                         val = buffer;
6591                                 }
6592                         }
6593                         break;
6594
6595                 case PGC_REAL:
6596                         {
6597                                 struct config_real *conf = (struct config_real *) record;
6598
6599                                 if (conf->show_hook)
6600                                         val = (*conf->show_hook) ();
6601                                 else
6602                                 {
6603                                         snprintf(buffer, sizeof(buffer), "%g",
6604                                                          *conf->variable);
6605                                         val = buffer;
6606                                 }
6607                         }
6608                         break;
6609
6610                 case PGC_STRING:
6611                         {
6612                                 struct config_string *conf = (struct config_string *) record;
6613
6614                                 if (conf->show_hook)
6615                                         val = (*conf->show_hook) ();
6616                                 else if (*conf->variable && **conf->variable)
6617                                         val = *conf->variable;
6618                                 else
6619                                         val = "";
6620                         }
6621                         break;
6622
6623                 case PGC_ENUM:
6624                         {
6625                                 struct config_enum *conf = (struct config_enum *) record;
6626
6627                                 if (conf->show_hook)
6628                                         val = (*conf->show_hook) ();
6629                                 else
6630                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6631                         }
6632                         break;
6633
6634                 default:
6635                         /* just to keep compiler quiet */
6636                         val = "???";
6637                         break;
6638         }
6639
6640         return pstrdup(val);
6641 }
6642
6643
6644 /*
6645  * Attempt (badly) to detect if a proposed new GUC setting is the same
6646  * as the current value.
6647  *
6648  * XXX this does not really work because it doesn't account for the
6649  * effects of canonicalization of string values by assign_hooks.
6650  */
6651 static bool
6652 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6653 {
6654         /* newvalue == NULL isn't supported */
6655         Assert(newvalue != NULL);
6656
6657         switch (record->vartype)
6658         {
6659                 case PGC_BOOL:
6660                         {
6661                                 struct config_bool *conf = (struct config_bool *) record;
6662                                 bool            newval;
6663
6664                                 return parse_bool(newvalue, &newval)
6665                                         && *conf->variable == newval;
6666                         }
6667                 case PGC_INT:
6668                         {
6669                                 struct config_int *conf = (struct config_int *) record;
6670                                 int                     newval;
6671
6672                                 return parse_int(newvalue, &newval, record->flags, NULL)
6673                                         && *conf->variable == newval;
6674                         }
6675                 case PGC_REAL:
6676                         {
6677                                 struct config_real *conf = (struct config_real *) record;
6678                                 double          newval;
6679
6680                                 return parse_real(newvalue, &newval)
6681                                         && *conf->variable == newval;
6682                         }
6683                 case PGC_STRING:
6684                         {
6685                                 struct config_string *conf = (struct config_string *) record;
6686
6687                                 return *conf->variable != NULL &&
6688                                         strcmp(*conf->variable, newvalue) == 0;
6689                         }
6690
6691                 case PGC_ENUM:
6692                         {
6693                                 struct config_enum *conf = (struct config_enum *) record;
6694                                 int                     newval;
6695
6696                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6697                                         *conf->variable == newval;
6698                         }
6699         }
6700
6701         return false;
6702 }
6703
6704
6705 #ifdef EXEC_BACKEND
6706
6707 /*
6708  *      These routines dump out all non-default GUC options into a binary
6709  *      file that is read by all exec'ed backends.  The format is:
6710  *
6711  *              variable name, string, null terminated
6712  *              variable value, string, null terminated
6713  *              variable source, integer
6714  */
6715 static void
6716 write_one_nondefault_variable(FILE *fp, struct config_generic * gconf)
6717 {
6718         if (gconf->source == PGC_S_DEFAULT)
6719                 return;
6720
6721         fprintf(fp, "%s", gconf->name);
6722         fputc(0, fp);
6723
6724         switch (gconf->vartype)
6725         {
6726                 case PGC_BOOL:
6727                         {
6728                                 struct config_bool *conf = (struct config_bool *) gconf;
6729
6730                                 if (*conf->variable)
6731                                         fprintf(fp, "true");
6732                                 else
6733                                         fprintf(fp, "false");
6734                         }
6735                         break;
6736
6737                 case PGC_INT:
6738                         {
6739                                 struct config_int *conf = (struct config_int *) gconf;
6740
6741                                 fprintf(fp, "%d", *conf->variable);
6742                         }
6743                         break;
6744
6745                 case PGC_REAL:
6746                         {
6747                                 struct config_real *conf = (struct config_real *) gconf;
6748
6749                                 /* Could lose precision here? */
6750                                 fprintf(fp, "%f", *conf->variable);
6751                         }
6752                         break;
6753
6754                 case PGC_STRING:
6755                         {
6756                                 struct config_string *conf = (struct config_string *) gconf;
6757
6758                                 fprintf(fp, "%s", *conf->variable);
6759                         }
6760                         break;
6761
6762                 case PGC_ENUM:
6763                         {
6764                                 struct config_enum *conf = (struct config_enum *) gconf;
6765
6766                                 fprintf(fp, "%s",
6767                                                 config_enum_lookup_by_value(conf, *conf->variable));
6768                         }
6769                         break;
6770         }
6771
6772         fputc(0, fp);
6773
6774         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6775 }
6776
6777 void
6778 write_nondefault_variables(GucContext context)
6779 {
6780         int                     elevel;
6781         FILE       *fp;
6782         struct config_generic *cvc_conf;
6783         int                     i;
6784
6785         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6786
6787         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6788
6789         /*
6790          * Open file
6791          */
6792         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6793         if (!fp)
6794         {
6795                 ereport(elevel,
6796                                 (errcode_for_file_access(),
6797                                  errmsg("could not write to file \"%s\": %m",
6798                                                 CONFIG_EXEC_PARAMS_NEW)));
6799                 return;
6800         }
6801
6802         /*
6803          * custom_variable_classes must be written out first; otherwise we might
6804          * reject custom variable values while reading the file.
6805          */
6806         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6807         if (cvc_conf)
6808                 write_one_nondefault_variable(fp, cvc_conf);
6809
6810         for (i = 0; i < num_guc_variables; i++)
6811         {
6812                 struct config_generic *gconf = guc_variables[i];
6813
6814                 if (gconf != cvc_conf)
6815                         write_one_nondefault_variable(fp, gconf);
6816         }
6817
6818         if (FreeFile(fp))
6819         {
6820                 ereport(elevel,
6821                                 (errcode_for_file_access(),
6822                                  errmsg("could not write to file \"%s\": %m",
6823                                                 CONFIG_EXEC_PARAMS_NEW)));
6824                 return;
6825         }
6826
6827         /*
6828          * Put new file in place.  This could delay on Win32, but we don't hold
6829          * any exclusive locks.
6830          */
6831         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6832 }
6833
6834
6835 /*
6836  *      Read string, including null byte from file
6837  *
6838  *      Return NULL on EOF and nothing read
6839  */
6840 static char *
6841 read_string_with_null(FILE *fp)
6842 {
6843         int                     i = 0,
6844                                 ch,
6845                                 maxlen = 256;
6846         char       *str = NULL;
6847
6848         do
6849         {
6850                 if ((ch = fgetc(fp)) == EOF)
6851                 {
6852                         if (i == 0)
6853                                 return NULL;
6854                         else
6855                                 elog(FATAL, "invalid format of exec config params file");
6856                 }
6857                 if (i == 0)
6858                         str = guc_malloc(FATAL, maxlen);
6859                 else if (i == maxlen)
6860                         str = guc_realloc(FATAL, str, maxlen *= 2);
6861                 str[i++] = ch;
6862         } while (ch != 0);
6863
6864         return str;
6865 }
6866
6867
6868 /*
6869  *      This routine loads a previous postmaster dump of its non-default
6870  *      settings.
6871  */
6872 void
6873 read_nondefault_variables(void)
6874 {
6875         FILE       *fp;
6876         char       *varname,
6877                            *varvalue;
6878         int                     varsource;
6879
6880         /*
6881          * Open file
6882          */
6883         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6884         if (!fp)
6885         {
6886                 /* File not found is fine */
6887                 if (errno != ENOENT)
6888                         ereport(FATAL,
6889                                         (errcode_for_file_access(),
6890                                          errmsg("could not read from file \"%s\": %m",
6891                                                         CONFIG_EXEC_PARAMS)));
6892                 return;
6893         }
6894
6895         for (;;)
6896         {
6897                 struct config_generic *record;
6898
6899                 if ((varname = read_string_with_null(fp)) == NULL)
6900                         break;
6901
6902                 if ((record = find_option(varname, true, FATAL)) == NULL)
6903                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6904                 if ((varvalue = read_string_with_null(fp)) == NULL)
6905                         elog(FATAL, "invalid format of exec config params file");
6906                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6907                         elog(FATAL, "invalid format of exec config params file");
6908
6909                 (void) set_config_option(varname, varvalue, record->context,
6910                                                                  varsource, GUC_ACTION_SET, true);
6911                 free(varname);
6912                 free(varvalue);
6913         }
6914
6915         FreeFile(fp);
6916 }
6917 #endif   /* EXEC_BACKEND */
6918
6919
6920 /*
6921  * A little "long argument" simulation, although not quite GNU
6922  * compliant. Takes a string of the form "some-option=some value" and
6923  * returns name = "some_option" and value = "some value" in malloc'ed
6924  * storage. Note that '-' is converted to '_' in the option name. If
6925  * there is no '=' in the input string then value will be NULL.
6926  */
6927 void
6928 ParseLongOption(const char *string, char **name, char **value)
6929 {
6930         size_t          equal_pos;
6931         char       *cp;
6932
6933         AssertArg(string);
6934         AssertArg(name);
6935         AssertArg(value);
6936
6937         equal_pos = strcspn(string, "=");
6938
6939         if (string[equal_pos] == '=')
6940         {
6941                 *name = guc_malloc(FATAL, equal_pos + 1);
6942                 strlcpy(*name, string, equal_pos + 1);
6943
6944                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6945         }
6946         else
6947         {
6948                 /* no equal sign in string */
6949                 *name = guc_strdup(FATAL, string);
6950                 *value = NULL;
6951         }
6952
6953         for (cp = *name; *cp; cp++)
6954                 if (*cp == '-')
6955                         *cp = '_';
6956 }
6957
6958
6959 /*
6960  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6961  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6962  *
6963  * The array parameter must be an array of TEXT (it must not be NULL).
6964  */
6965 void
6966 ProcessGUCArray(ArrayType *array,
6967                                 GucContext context, GucSource source, GucAction action)
6968 {
6969         int                     i;
6970
6971         Assert(array != NULL);
6972         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6973         Assert(ARR_NDIM(array) == 1);
6974         Assert(ARR_LBOUND(array)[0] == 1);
6975
6976         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6977         {
6978                 Datum           d;
6979                 bool            isnull;
6980                 char       *s;
6981                 char       *name;
6982                 char       *value;
6983
6984                 d = array_ref(array, 1, &i,
6985                                           -1 /* varlenarray */ ,
6986                                           -1 /* TEXT's typlen */ ,
6987                                           false /* TEXT's typbyval */ ,
6988                                           'i' /* TEXT's typalign */ ,
6989                                           &isnull);
6990
6991                 if (isnull)
6992                         continue;
6993
6994                 s = TextDatumGetCString(d);
6995
6996                 ParseLongOption(s, &name, &value);
6997                 if (!value)
6998                 {
6999                         ereport(WARNING,
7000                                         (errcode(ERRCODE_SYNTAX_ERROR),
7001                                          errmsg("could not parse setting for parameter \"%s\"",
7002                                                         name)));
7003                         free(name);
7004                         continue;
7005                 }
7006
7007                 (void) set_config_option(name, value, context, source, action, true);
7008
7009                 free(name);
7010                 if (value)
7011                         free(value);
7012         }
7013 }
7014
7015
7016 /*
7017  * Add an entry to an option array.  The array parameter may be NULL
7018  * to indicate the current table entry is NULL.
7019  */
7020 ArrayType *
7021 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7022 {
7023         const char *varname;
7024         Datum           datum;
7025         char       *newval;
7026         ArrayType  *a;
7027
7028         Assert(name);
7029         Assert(value);
7030
7031         /* test if the option is valid */
7032         set_config_option(name, value,
7033                                           superuser() ? PGC_SUSET : PGC_USERSET,
7034                                           PGC_S_TEST, GUC_ACTION_SET, false);
7035
7036         /* convert name to canonical spelling, so we can use plain strcmp */
7037         (void) GetConfigOptionByName(name, &varname);
7038         name = varname;
7039
7040         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7041         sprintf(newval, "%s=%s", name, value);
7042         datum = CStringGetTextDatum(newval);
7043
7044         if (array)
7045         {
7046                 int                     index;
7047                 bool            isnull;
7048                 int                     i;
7049
7050                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7051                 Assert(ARR_NDIM(array) == 1);
7052                 Assert(ARR_LBOUND(array)[0] == 1);
7053
7054                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7055
7056                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7057                 {
7058                         Datum           d;
7059                         char       *current;
7060
7061                         d = array_ref(array, 1, &i,
7062                                                   -1 /* varlenarray */ ,
7063                                                   -1 /* TEXT's typlen */ ,
7064                                                   false /* TEXT's typbyval */ ,
7065                                                   'i' /* TEXT's typalign */ ,
7066                                                   &isnull);
7067                         if (isnull)
7068                                 continue;
7069                         current = TextDatumGetCString(d);
7070                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7071                         {
7072                                 index = i;
7073                                 break;
7074                         }
7075                 }
7076
7077                 a = array_set(array, 1, &index,
7078                                           datum,
7079                                           false,
7080                                           -1 /* varlena array */ ,
7081                                           -1 /* TEXT's typlen */ ,
7082                                           false /* TEXT's typbyval */ ,
7083                                           'i' /* TEXT's typalign */ );
7084         }
7085         else
7086                 a = construct_array(&datum, 1,
7087                                                         TEXTOID,
7088                                                         -1, false, 'i');
7089
7090         return a;
7091 }
7092
7093
7094 /*
7095  * Delete an entry from an option array.  The array parameter may be NULL
7096  * to indicate the current table entry is NULL.  Also, if the return value
7097  * is NULL then a null should be stored.
7098  */
7099 ArrayType *
7100 GUCArrayDelete(ArrayType *array, const char *name)
7101 {
7102         const char *varname;
7103         ArrayType  *newarray;
7104         int                     i;
7105         int                     index;
7106
7107         Assert(name);
7108
7109         /* test if the option is valid */
7110         set_config_option(name, NULL,
7111                                           superuser() ? PGC_SUSET : PGC_USERSET,
7112                                           PGC_S_TEST, GUC_ACTION_SET, false);
7113
7114         /* convert name to canonical spelling, so we can use plain strcmp */
7115         (void) GetConfigOptionByName(name, &varname);
7116         name = varname;
7117
7118         /* if array is currently null, then surely nothing to delete */
7119         if (!array)
7120                 return NULL;
7121
7122         newarray = NULL;
7123         index = 1;
7124
7125         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7126         {
7127                 Datum           d;
7128                 char       *val;
7129                 bool            isnull;
7130
7131                 d = array_ref(array, 1, &i,
7132                                           -1 /* varlenarray */ ,
7133                                           -1 /* TEXT's typlen */ ,
7134                                           false /* TEXT's typbyval */ ,
7135                                           'i' /* TEXT's typalign */ ,
7136                                           &isnull);
7137                 if (isnull)
7138                         continue;
7139                 val = TextDatumGetCString(d);
7140
7141                 /* ignore entry if it's what we want to delete */
7142                 if (strncmp(val, name, strlen(name)) == 0
7143                         && val[strlen(name)] == '=')
7144                         continue;
7145
7146                 /* else add it to the output array */
7147                 if (newarray)
7148                 {
7149                         newarray = array_set(newarray, 1, &index,
7150                                                                  d,
7151                                                                  false,
7152                                                                  -1 /* varlenarray */ ,
7153                                                                  -1 /* TEXT's typlen */ ,
7154                                                                  false /* TEXT's typbyval */ ,
7155                                                                  'i' /* TEXT's typalign */ );
7156                 }
7157                 else
7158                         newarray = construct_array(&d, 1,
7159                                                                            TEXTOID,
7160                                                                            -1, false, 'i');
7161
7162                 index++;
7163         }
7164
7165         return newarray;
7166 }
7167
7168
7169 /*
7170  * assign_hook and show_hook subroutines
7171  */
7172
7173 static const char *
7174 assign_log_destination(const char *value, bool doit, GucSource source)
7175 {
7176         char       *rawstring;
7177         List       *elemlist;
7178         ListCell   *l;
7179         int                     newlogdest = 0;
7180
7181         /* Need a modifiable copy of string */
7182         rawstring = pstrdup(value);
7183
7184         /* Parse string into list of identifiers */
7185         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7186         {
7187                 /* syntax error in list */
7188                 pfree(rawstring);
7189                 list_free(elemlist);
7190                 ereport(GUC_complaint_elevel(source),
7191                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7192                    errmsg("invalid list syntax for parameter \"log_destination\"")));
7193                 return NULL;
7194         }
7195
7196         foreach(l, elemlist)
7197         {
7198                 char       *tok = (char *) lfirst(l);
7199
7200                 if (pg_strcasecmp(tok, "stderr") == 0)
7201                         newlogdest |= LOG_DESTINATION_STDERR;
7202                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7203                         newlogdest |= LOG_DESTINATION_CSVLOG;
7204 #ifdef HAVE_SYSLOG
7205                 else if (pg_strcasecmp(tok, "syslog") == 0)
7206                         newlogdest |= LOG_DESTINATION_SYSLOG;
7207 #endif
7208 #ifdef WIN32
7209                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7210                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7211 #endif
7212                 else
7213                 {
7214                         ereport(GUC_complaint_elevel(source),
7215                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7216                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7217                                                  tok)));
7218                         pfree(rawstring);
7219                         list_free(elemlist);
7220                         return NULL;
7221                 }
7222         }
7223
7224         if (doit)
7225                 Log_destination = newlogdest;
7226
7227         pfree(rawstring);
7228         list_free(elemlist);
7229
7230         return value;
7231 }
7232
7233 #ifdef HAVE_SYSLOG
7234
7235 static bool
7236 assign_syslog_facility(int newval, bool doit, GucSource source)
7237 {
7238         if (doit)
7239                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7240                                                           newval);
7241
7242         return true;
7243 }
7244
7245 static const char *
7246 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7247 {
7248         if (doit)
7249                 set_syslog_parameters(ident, syslog_facility);
7250
7251         return ident;
7252 }
7253 #endif   /* HAVE_SYSLOG */
7254
7255
7256 static bool
7257 assign_session_replication_role(int newval, bool doit, GucSource source)
7258 {
7259         /*
7260          * Must flush the plan cache when changing replication role; but don't
7261          * flush unnecessarily.
7262          */
7263         if (doit && SessionReplicationRole != newval)
7264         {
7265                 ResetPlanCache();
7266         }
7267
7268         return true;
7269 }
7270
7271 static const char *
7272 show_num_temp_buffers(void)
7273 {
7274         /*
7275          * We show the GUC var until local buffers have been initialized, and
7276          * NLocBuffer afterwards.
7277          */
7278         static char nbuf[32];
7279
7280         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7281         return nbuf;
7282 }
7283
7284 static bool
7285 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7286 {
7287         if (!newval)
7288         {
7289                 ereport(GUC_complaint_elevel(source),
7290                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7291                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7292                 return false;
7293         }
7294         return true;
7295 }
7296
7297 static const char *
7298 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7299 {
7300         /*
7301          * Check syntax. newval must be a comma separated list of identifiers.
7302          * Whitespace is allowed but removed from the result.
7303          */
7304         bool            hasSpaceAfterToken = false;
7305         const char *cp = newval;
7306         int                     symLen = 0;
7307         char            c;
7308         StringInfoData buf;
7309
7310         initStringInfo(&buf);
7311         while ((c = *cp++) != '\0')
7312         {
7313                 if (isspace((unsigned char) c))
7314                 {
7315                         if (symLen > 0)
7316                                 hasSpaceAfterToken = true;
7317                         continue;
7318                 }
7319
7320                 if (c == ',')
7321                 {
7322                         if (symLen > 0)         /* terminate identifier */
7323                         {
7324                                 appendStringInfoChar(&buf, ',');
7325                                 symLen = 0;
7326                         }
7327                         hasSpaceAfterToken = false;
7328                         continue;
7329                 }
7330
7331                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7332                 {
7333                         /*
7334                          * Syntax error due to token following space after token or
7335                          * non-identifier character
7336                          */
7337                         pfree(buf.data);
7338                         return NULL;
7339                 }
7340                 appendStringInfoChar(&buf, c);
7341                 symLen++;
7342         }
7343
7344         /* Remove stray ',' at end */
7345         if (symLen == 0 && buf.len > 0)
7346                 buf.data[--buf.len] = '\0';
7347
7348         /* GUC wants the result malloc'd */
7349         newval = guc_strdup(LOG, buf.data);
7350
7351         pfree(buf.data);
7352         return newval;
7353 }
7354
7355 static bool
7356 assign_debug_assertions(bool newval, bool doit, GucSource source)
7357 {
7358 #ifndef USE_ASSERT_CHECKING
7359         if (newval)
7360         {
7361                 ereport(GUC_complaint_elevel(source),
7362                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7363                            errmsg("assertion checking is not supported by this build")));
7364                 return false;
7365         }
7366 #endif
7367         return true;
7368 }
7369
7370 static bool
7371 assign_ssl(bool newval, bool doit, GucSource source)
7372 {
7373 #ifndef USE_SSL
7374         if (newval)
7375         {
7376                 ereport(GUC_complaint_elevel(source),
7377                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7378                                  errmsg("SSL is not supported by this build")));
7379                 return false;
7380         }
7381 #endif
7382         return true;
7383 }
7384
7385 static bool
7386 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7387 {
7388         if (newval && log_statement_stats)
7389         {
7390                 ereport(GUC_complaint_elevel(source),
7391                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7392                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7393                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7394                 if (source != PGC_S_OVERRIDE)
7395                         return false;
7396         }
7397         return true;
7398 }
7399
7400 static bool
7401 assign_log_stats(bool newval, bool doit, GucSource source)
7402 {
7403         if (newval &&
7404                 (log_parser_stats || log_planner_stats || log_executor_stats))
7405         {
7406                 ereport(GUC_complaint_elevel(source),
7407                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7408                                  errmsg("cannot enable \"log_statement_stats\" when "
7409                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7410                                                 "or \"log_executor_stats\" is true")));
7411                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7412                 if (source != PGC_S_OVERRIDE)
7413                         return false;
7414         }
7415         return true;
7416 }
7417
7418 static bool
7419 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7420 {
7421         /* Can't go to r/w mode inside a r/o transaction */
7422         if (newval == false && XactReadOnly && IsSubTransaction())
7423         {
7424                 ereport(GUC_complaint_elevel(source),
7425                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7426                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7427                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7428                 if (source != PGC_S_OVERRIDE)
7429                         return false;
7430         }
7431         return true;
7432 }
7433
7434 static const char *
7435 assign_canonical_path(const char *newval, bool doit, GucSource source)
7436 {
7437         if (doit)
7438         {
7439                 char       *canon_val = guc_strdup(ERROR, newval);
7440
7441                 canonicalize_path(canon_val);
7442                 return canon_val;
7443         }
7444         else
7445                 return newval;
7446 }
7447
7448 static const char *
7449 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7450 {
7451         /*
7452          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7453          * When we see this we just do nothing.  If this value isn't overridden
7454          * from the config file then pg_timezone_abbrev_initialize() will
7455          * eventually replace it with "Default".  This hack has two purposes: to
7456          * avoid wasting cycles loading values that might soon be overridden from
7457          * the config file, and to avoid trying to read the timezone abbrev files
7458          * during InitializeGUCOptions().  The latter doesn't work in an
7459          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7460          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7461          * delay initializing TimeZone ... if we have any more, we should try to
7462          * clean up and centralize this mechanism ...)
7463          */
7464         if (strcmp(newval, "UNKNOWN") == 0)
7465         {
7466                 return newval;
7467         }
7468
7469         /* Loading abbrev file is expensive, so only do it when value changes */
7470         if (timezone_abbreviations_string == NULL ||
7471                 strcmp(timezone_abbreviations_string, newval) != 0)
7472         {
7473                 int                     elevel;
7474
7475                 /*
7476                  * If reading config file, only the postmaster should bleat loudly
7477                  * about problems.      Otherwise, it's just this one process doing it,
7478                  * and we use WARNING message level.
7479                  */
7480                 if (source == PGC_S_FILE)
7481                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7482                 else
7483                         elevel = WARNING;
7484                 if (!load_tzoffsets(newval, doit, elevel))
7485                         return NULL;
7486         }
7487         return newval;
7488 }
7489
7490 /*
7491  * pg_timezone_abbrev_initialize --- set default value if not done already
7492  *
7493  * This is called after initial loading of postgresql.conf.  If no
7494  * timezone_abbreviations setting was found therein, select default.
7495  */
7496 void
7497 pg_timezone_abbrev_initialize(void)
7498 {
7499         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7500         {
7501                 SetConfigOption("timezone_abbreviations", "Default",
7502                                                 PGC_POSTMASTER, PGC_S_ARGV);
7503         }
7504 }
7505
7506 static const char *
7507 show_archive_command(void)
7508 {
7509         if (XLogArchiveMode)
7510                 return XLogArchiveCommand;
7511         else
7512                 return "(disabled)";
7513 }
7514
7515 static bool
7516 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7517 {
7518         if (doit)
7519                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7520
7521         return true;
7522 }
7523
7524 static const char *
7525 show_tcp_keepalives_idle(void)
7526 {
7527         static char nbuf[16];
7528
7529         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7530         return nbuf;
7531 }
7532
7533 static bool
7534 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7535 {
7536         if (doit)
7537                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7538
7539         return true;
7540 }
7541
7542 static const char *
7543 show_tcp_keepalives_interval(void)
7544 {
7545         static char nbuf[16];
7546
7547         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7548         return nbuf;
7549 }
7550
7551 static bool
7552 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7553 {
7554         if (doit)
7555                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7556
7557         return true;
7558 }
7559
7560 static const char *
7561 show_tcp_keepalives_count(void)
7562 {
7563         static char nbuf[16];
7564
7565         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7566         return nbuf;
7567 }
7568
7569 static bool
7570 assign_maxconnections(int newval, bool doit, GucSource source)
7571 {
7572         if (newval + autovacuum_max_workers > INT_MAX / 4)
7573                 return false;
7574
7575         if (doit)
7576                 MaxBackends = newval + autovacuum_max_workers;
7577
7578         return true;
7579 }
7580
7581 static bool
7582 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7583 {
7584         if (newval + MaxConnections > INT_MAX / 4)
7585                 return false;
7586
7587         if (doit)
7588                 MaxBackends = newval + MaxConnections;
7589
7590         return true;
7591 }
7592
7593 static bool
7594 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7595 {
7596 #ifdef USE_PREFETCH
7597         double          new_prefetch_pages = 0.0;
7598         int                     i;
7599
7600         /*----------
7601          * The user-visible GUC parameter is the number of drives (spindles),
7602          * which we need to translate to a number-of-pages-to-prefetch target.
7603          *
7604          * The expected number of prefetch pages needed to keep N drives busy is:
7605          *
7606          * drives |   I/O requests
7607          * -------+----------------
7608          *              1 |   1
7609          *              2 |   2/1 + 2/2 = 3
7610          *              3 |   3/1 + 3/2 + 3/3 = 5 1/2
7611          *              4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7612          *              n |   n * H(n)
7613          *
7614          * This is called the "coupon collector problem" and H(n) is called the
7615          * harmonic series.  This could be approximated by n * ln(n), but for
7616          * reasonable numbers of drives we might as well just compute the series.
7617          *
7618          * Alternatively we could set the target to the number of pages necessary
7619          * so that the expected number of active spindles is some arbitrary
7620          * percentage of the total.  This sounds the same but is actually slightly
7621          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7622          * that desired fraction.
7623          *
7624          * Experimental results show that both of these formulas aren't aggressive
7625          * enough, but we don't really have any better proposals.
7626          *
7627          * Note that if newval = 0 (disabled), we must set target = 0.
7628          *----------
7629          */
7630
7631         for (i = 1; i <= newval; i++)
7632                 new_prefetch_pages += (double) newval / (double) i;
7633
7634         /* This range check shouldn't fail, but let's be paranoid */
7635         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7636         {
7637                 if (doit)
7638                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7639                 return true;
7640         }
7641         else
7642                 return false;
7643 #else
7644         return true;
7645 #endif   /* USE_PREFETCH */
7646 }
7647
7648 static const char *
7649 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7650 {
7651         if (doit)
7652         {
7653                 char       *canon_val = guc_strdup(ERROR, newval);
7654                 char       *tname;
7655                 char       *fname;
7656
7657                 canonicalize_path(canon_val);
7658
7659                 tname = guc_malloc(ERROR, strlen(canon_val) + 12);              /* /pgstat.tmp */
7660                 sprintf(tname, "%s/pgstat.tmp", canon_val);
7661                 fname = guc_malloc(ERROR, strlen(canon_val) + 13);              /* /pgstat.stat */
7662                 sprintf(fname, "%s/pgstat.stat", canon_val);
7663
7664                 if (pgstat_stat_tmpname)
7665                         free(pgstat_stat_tmpname);
7666                 pgstat_stat_tmpname = tname;
7667                 if (pgstat_stat_filename)
7668                         free(pgstat_stat_filename);
7669                 pgstat_stat_filename = fname;
7670
7671                 return canon_val;
7672         }
7673         else
7674                 return newval;
7675 }
7676
7677 #include "guc-file.c"