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) 2000-2008, 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 1.449 2008/04/29 20:44:49 tgl Exp $
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <limits.h>
  22 #include <unistd.h>
  23 #include <sys/stat.h>
  24 #ifdef HAVE_SYSLOG
  25 #include <syslog.h>
  26 #endif
  27
  28 #include "access/gin.h"
  29 #include "access/transam.h"
  30 #include "access/twophase.h"
  31 #include "access/xact.h"
  32 #include "catalog/namespace.h"
  33 #include "commands/async.h"
  34 #include "commands/prepare.h"
  35 #include "commands/vacuum.h"
  36 #include "commands/variable.h"
  37 #include "commands/trigger.h"
  38 #include "funcapi.h"
  39 #include "libpq/auth.h"
  40 #include "libpq/pqformat.h"
  41 #include "miscadmin.h"
  42 #include "optimizer/cost.h"
  43 #include "optimizer/geqo.h"
  44 #include "optimizer/paths.h"
  45 #include "optimizer/planmain.h"
  46 #include "parser/gramparse.h"
  47 #include "parser/parse_expr.h"
  48 #include "parser/parse_relation.h"
  49 #include "parser/parse_type.h"
  50 #include "parser/scansup.h"
  51 #include "pgstat.h"
  52 #include "postmaster/autovacuum.h"
  53 #include "postmaster/bgwriter.h"
  54 #include "postmaster/postmaster.h"
  55 #include "postmaster/syslogger.h"
  56 #include "postmaster/walwriter.h"
  57 #include "regex/regex.h"
  58 #include "storage/fd.h"
  59 #include "storage/freespace.h"
  60 #include "tcop/tcopprot.h"
  61 #include "tsearch/ts_cache.h"
  62 #include "utils/builtins.h"
  63 #include "utils/guc_tables.h"
  64 #include "utils/memutils.h"
  65 #include "utils/pg_locale.h"
  66 #include "utils/plancache.h"
  67 #include "utils/portal.h"
  68 #include "utils/ps_status.h"
  69 #include "utils/tzparser.h"
  70 #include "utils/xml.h"
  71
  72 #ifndef PG_KRB_SRVTAB
  73 #define PG_KRB_SRVTAB ""
  74 #endif
  75 #ifndef PG_KRB_SRVNAM
  76 #define PG_KRB_SRVNAM ""
  77 #endif
  78
  79 #define CONFIG_FILENAME "postgresql.conf"
  80 #define HBA_FILENAME    "pg_hba.conf"
  81 #define IDENT_FILENAME  "pg_ident.conf"
  82
  83 #ifdef EXEC_BACKEND
  84 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  85 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  86 #endif
  87
  88 /* upper limit for GUC variables measured in kilobytes of memory */
  89 #if SIZEOF_SIZE_T > 4
  90 #define MAX_KILOBYTES   INT_MAX
  91 #else
  92 #define MAX_KILOBYTES   (INT_MAX / 1024)
  93 #endif
  94
  95 #define KB_PER_MB (1024)
  96 #define KB_PER_GB (1024*1024)
  97
  98 #define MS_PER_S 1000
  99 #define S_PER_MIN 60
 100 #define MS_PER_MIN (1000 * 60)
 101 #define MIN_PER_H 60
 102 #define S_PER_H (60 * 60)
 103 #define MS_PER_H (1000 * 60 * 60)
 104 #define MIN_PER_D (60 * 24)
 105 #define S_PER_D (60 * 60 * 24)
 106 #define MS_PER_D (1000 * 60 * 60 * 24)
 107
 108 /* XXX these should appear in other modules' header files */
 109 extern bool Log_disconnections;
 110 extern int      CommitDelay;
 111 extern int      CommitSiblings;
 112 extern char *default_tablespace;
 113 extern char *temp_tablespaces;
 114 extern bool synchronize_seqscans;
 115 extern bool fullPageWrites;
 116
 117 #ifdef TRACE_SORT
 118 extern bool trace_sort;
 119 #endif
 120 #ifdef TRACE_SYNCSCAN
 121 extern bool trace_syncscan;
 122 #endif
 123 #ifdef DEBUG_BOUNDED_SORT
 124 extern bool optimize_bounded_sort;
 125 #endif
 126
 127 #ifdef USE_SSL
 128 extern char *SSLCipherSuites;
 129 #endif
 130
 131
 132 static const char *assign_log_destination(const char *value,
 133                                            bool doit, GucSource source);
 134
 135 #ifdef HAVE_SYSLOG
 136 static int      syslog_facility = LOG_LOCAL0;
 137
 138 static bool assign_syslog_facility(int newval,
 139                                     bool doit, GucSource source);
 140 static const char *assign_syslog_ident(const char *ident,
 141                                         bool doit, GucSource source);
 142 #endif
 143
 144 static bool assign_session_replication_role(int newval, bool doit,
 145                                                                 GucSource source);
 146 static const char *show_num_temp_buffers(void);
 147 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 148 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 149                                                            GucSource source);
 150 static bool assign_debug_assertions(bool newval, bool doit, GucSource source);
 151 static bool assign_ssl(bool newval, bool doit, GucSource source);
 152 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 153 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 154 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 155 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 156 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 157 static const char *show_archive_command(void);
 158 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 159 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 160 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 161 static const char *show_tcp_keepalives_idle(void);
 162 static const char *show_tcp_keepalives_interval(void);
 163 static const char *show_tcp_keepalives_count(void);
 164 static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource source);
 165 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 166
 167 static char *config_enum_get_options(struct config_enum *record,
 168                                                                          const char *prefix, const char *suffix);
 169
 170
 171
 172 /*
 173  * Options for enum values defined in this module.
 174  */
 175 static const struct config_enum_entry message_level_options[] = {
 176         {"debug", DEBUG2},
 177         {"debug5", DEBUG5},
 178         {"debug4", DEBUG4},
 179         {"debug3", DEBUG3},
 180         {"debug2", DEBUG2},
 181         {"debug1", DEBUG1},
 182         {"log", LOG},
 183         {"info", INFO},
 184         {"notice", NOTICE},
 185         {"warning", WARNING},
 186         {"error", ERROR},
 187         {"fatal", FATAL},
 188         {"panic", PANIC},
 189         {NULL, 0}
 190 };
 191
 192 static const struct config_enum_entry log_error_verbosity_options[] = {
 193         {"default", PGERROR_DEFAULT},
 194         {"terse", PGERROR_TERSE},
 195         {"verbose", PGERROR_VERBOSE},
 196         {NULL, 0}
 197 };
 198
 199 static const struct config_enum_entry log_statement_options[] = {
 200         {"none", LOGSTMT_NONE},
 201         {"ddl", LOGSTMT_DDL},
 202         {"mod", LOGSTMT_MOD},
 203         {"all", LOGSTMT_ALL},
 204         {NULL, 0}
 205 };
 206
 207 static const struct config_enum_entry regex_flavor_options[] = {
 208     {"advanced", REG_ADVANCED},
 209     {"extended", REG_EXTENDED},
 210     {"basic", REG_BASIC},
 211     {NULL, 0}
 212 };
 213
 214 static const struct config_enum_entry isolation_level_options[] = {
 215         {"serializable", XACT_SERIALIZABLE},
 216         {"repeatable read", XACT_REPEATABLE_READ},
 217         {"read committed", XACT_READ_COMMITTED},
 218         {"read uncommitted", XACT_READ_UNCOMMITTED},
 219         {NULL, 0}
 220 };
 221
 222 static const struct config_enum_entry session_replication_role_options[] = {
 223         {"origin", SESSION_REPLICATION_ROLE_ORIGIN},
 224         {"replica", SESSION_REPLICATION_ROLE_REPLICA},
 225         {"local", SESSION_REPLICATION_ROLE_LOCAL},
 226         {NULL, 0}
 227 };
 228
 229 #ifdef HAVE_SYSLOG
 230 static const struct config_enum_entry syslog_facility_options[] = {
 231         {"local0", LOG_LOCAL0},
 232         {"local1", LOG_LOCAL1},
 233         {"local2", LOG_LOCAL2},
 234         {"local3", LOG_LOCAL3},
 235         {"local4", LOG_LOCAL4},
 236         {"local5", LOG_LOCAL5},
 237         {"local6", LOG_LOCAL6},
 238         {"local7", LOG_LOCAL7},
 239         {NULL, 0}
 240 };
 241 #endif
 242
 243 static const struct config_enum_entry xmlbinary_options[] = {
 244         {"base64", XMLBINARY_BASE64},
 245         {"hex", XMLBINARY_HEX},
 246         {NULL, 0}
 247 };
 248
 249 static const struct config_enum_entry xmloption_options[] = {
 250         {"content", XMLOPTION_CONTENT},
 251         {"document", XMLOPTION_DOCUMENT},
 252         {NULL, 0}
 253 };
 254
 255 /*
 256  * Although only "on", "off", and "safe_encoding" are documented, we
 257  * accept all the likely variants of "on" and "off".
 258  */
 259 static const struct config_enum_entry backslash_quote_options[] = {
 260         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING},
 261         {"on", BACKSLASH_QUOTE_ON},
 262         {"off", BACKSLASH_QUOTE_OFF},
 263         {"true", BACKSLASH_QUOTE_ON},
 264         {"false", BACKSLASH_QUOTE_OFF},
 265         {"yes", BACKSLASH_QUOTE_ON},
 266         {"no", BACKSLASH_QUOTE_OFF},
 267         {"1", BACKSLASH_QUOTE_ON},
 268         {"0", BACKSLASH_QUOTE_OFF},
 269         {NULL, 0}
 270 };
 271
 272 /*
 273  * GUC option variables that are exported from this module
 274  */
 275 #ifdef USE_ASSERT_CHECKING
 276 bool            assert_enabled = true;
 277 #else
 278 bool            assert_enabled = false;
 279 #endif
 280 bool            log_duration = false;
 281 bool            Debug_print_plan = false;
 282 bool            Debug_print_parse = false;
 283 bool            Debug_print_rewritten = false;
 284 bool            Debug_pretty_print = false;
 285
 286 bool            log_parser_stats = false;
 287 bool            log_planner_stats = false;
 288 bool            log_executor_stats = false;
 289 bool            log_statement_stats = false;            /* this is sort of all three
 290                                                                                                  * above together */
 291 bool            log_btree_build_stats = false;
 292
 293 bool            check_function_bodies = true;
 294 bool            default_with_oids = false;
 295 bool            SQL_inheritance = true;
 296
 297 bool            Password_encryption = true;
 298
 299 int                     log_min_error_statement = ERROR;
 300 int                     log_min_messages = WARNING;
 301 int                     client_min_messages = NOTICE;
 302 int                     log_min_duration_statement = -1;
 303 int                     log_temp_files = -1;
 304
 305 int                     num_temp_buffers = 1000;
 306
 307 char       *ConfigFileName;
 308 char       *HbaFileName;
 309 char       *IdentFileName;
 310 char       *external_pid_file;
 311
 312 int                     tcp_keepalives_idle;
 313 int                     tcp_keepalives_interval;
 314 int                     tcp_keepalives_count;
 315
 316 /*
 317  * These variables are all dummies that don't do anything, except in some
 318  * cases provide the value for SHOW to display.  The real state is elsewhere
 319  * and is kept in sync by assign_hooks.
 320  */
 321 static char *log_destination_string;
 322
 323 #ifdef HAVE_SYSLOG
 324 static char *syslog_ident_str;
 325 #endif
 326 static bool phony_autocommit;
 327 static bool session_auth_is_superuser;
 328 static double phony_random_seed;
 329 static char *client_encoding_string;
 330 static char *datestyle_string;
 331 static char *locale_collate;
 332 static char *locale_ctype;
 333 static char *server_encoding_string;
 334 static char *server_version_string;
 335 static int      server_version_num;
 336 static char *timezone_string;
 337 static char *log_timezone_string;
 338 static char *timezone_abbreviations_string;
 339 static char *XactIsoLevel_string;
 340 static char *data_directory;
 341 static char *custom_variable_classes;
 342 static int      max_function_args;
 343 static int      max_index_keys;
 344 static int      max_identifier_length;
 345 static int      block_size;
 346 static bool integer_datetimes;
 347
 348 /* should be static, but commands/variable.c needs to get at these */
 349 char       *role_string;
 350 char       *session_authorization_string;
 351
 352
 353 /*
 354  * Displayable names for context types (enum GucContext)
 355  *
 356  * Note: these strings are deliberately not localized.
 357  */
 358 const char *const GucContext_Names[] =
 359 {
 360          /* PGC_INTERNAL */ "internal",
 361          /* PGC_POSTMASTER */ "postmaster",
 362          /* PGC_SIGHUP */ "sighup",
 363          /* PGC_BACKEND */ "backend",
 364          /* PGC_SUSET */ "superuser",
 365          /* PGC_USERSET */ "user"
 366 };
 367
 368 /*
 369  * Displayable names for source types (enum GucSource)
 370  *
 371  * Note: these strings are deliberately not localized.
 372  */
 373 const char *const GucSource_Names[] =
 374 {
 375          /* PGC_S_DEFAULT */ "default",
 376          /* PGC_S_ENV_VAR */ "environment variable",
 377          /* PGC_S_FILE */ "configuration file",
 378          /* PGC_S_ARGV */ "command line",
 379          /* PGC_S_DATABASE */ "database",
 380          /* PGC_S_USER */ "user",
 381          /* PGC_S_CLIENT */ "client",
 382          /* PGC_S_OVERRIDE */ "override",
 383          /* PGC_S_INTERACTIVE */ "interactive",
 384          /* PGC_S_TEST */ "test",
 385          /* PGC_S_SESSION */ "session"
 386 };
 387
 388 /*
 389  * Displayable names for the groupings defined in enum config_group
 390  */
 391 const char *const config_group_names[] =
 392 {
 393         /* UNGROUPED */
 394         gettext_noop("Ungrouped"),
 395         /* FILE_LOCATIONS */
 396         gettext_noop("File Locations"),
 397         /* CONN_AUTH */
 398         gettext_noop("Connections and Authentication"),
 399         /* CONN_AUTH_SETTINGS */
 400         gettext_noop("Connections and Authentication / Connection Settings"),
 401         /* CONN_AUTH_SECURITY */
 402         gettext_noop("Connections and Authentication / Security and Authentication"),
 403         /* RESOURCES */
 404         gettext_noop("Resource Usage"),
 405         /* RESOURCES_MEM */
 406         gettext_noop("Resource Usage / Memory"),
 407         /* RESOURCES_FSM */
 408         gettext_noop("Resource Usage / Free Space Map"),
 409         /* RESOURCES_KERNEL */
 410         gettext_noop("Resource Usage / Kernel Resources"),
 411         /* WAL */
 412         gettext_noop("Write-Ahead Log"),
 413         /* WAL_SETTINGS */
 414         gettext_noop("Write-Ahead Log / Settings"),
 415         /* WAL_CHECKPOINTS */
 416         gettext_noop("Write-Ahead Log / Checkpoints"),
 417         /* QUERY_TUNING */
 418         gettext_noop("Query Tuning"),
 419         /* QUERY_TUNING_METHOD */
 420         gettext_noop("Query Tuning / Planner Method Configuration"),
 421         /* QUERY_TUNING_COST */
 422         gettext_noop("Query Tuning / Planner Cost Constants"),
 423         /* QUERY_TUNING_GEQO */
 424         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 425         /* QUERY_TUNING_OTHER */
 426         gettext_noop("Query Tuning / Other Planner Options"),
 427         /* LOGGING */
 428         gettext_noop("Reporting and Logging"),
 429         /* LOGGING_WHERE */
 430         gettext_noop("Reporting and Logging / Where to Log"),
 431         /* LOGGING_WHEN */
 432         gettext_noop("Reporting and Logging / When to Log"),
 433         /* LOGGING_WHAT */
 434         gettext_noop("Reporting and Logging / What to Log"),
 435         /* STATS */
 436         gettext_noop("Statistics"),
 437         /* STATS_MONITORING */
 438         gettext_noop("Statistics / Monitoring"),
 439         /* STATS_COLLECTOR */
 440         gettext_noop("Statistics / Query and Index Statistics Collector"),
 441         /* AUTOVACUUM */
 442         gettext_noop("Autovacuum"),
 443         /* CLIENT_CONN */
 444         gettext_noop("Client Connection Defaults"),
 445         /* CLIENT_CONN_STATEMENT */
 446         gettext_noop("Client Connection Defaults / Statement Behavior"),
 447         /* CLIENT_CONN_LOCALE */
 448         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 449         /* CLIENT_CONN_OTHER */
 450         gettext_noop("Client Connection Defaults / Other Defaults"),
 451         /* LOCK_MANAGEMENT */
 452         gettext_noop("Lock Management"),
 453         /* COMPAT_OPTIONS */
 454         gettext_noop("Version and Platform Compatibility"),
 455         /* COMPAT_OPTIONS_PREVIOUS */
 456         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 457         /* COMPAT_OPTIONS_CLIENT */
 458         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 459         /* PRESET_OPTIONS */
 460         gettext_noop("Preset Options"),
 461         /* CUSTOM_OPTIONS */
 462         gettext_noop("Customized Options"),
 463         /* DEVELOPER_OPTIONS */
 464         gettext_noop("Developer Options"),
 465         /* help_config wants this array to be null-terminated */
 466         NULL
 467 };
 468
 469 /*
 470  * Displayable names for GUC variable types (enum config_type)
 471  *
 472  * Note: these strings are deliberately not localized.
 473  */
 474 const char *const config_type_names[] =
 475 {
 476          /* PGC_BOOL */ "bool",
 477          /* PGC_INT */ "integer",
 478          /* PGC_REAL */ "real",
 479          /* PGC_STRING */ "string",
 480          /* PGC_ENUM */ "enum"
 481 };
 482
 483
 484 /*
 485  * Contents of GUC tables
 486  *
 487  * See src/backend/utils/misc/README for design notes.
 488  *
 489  * TO ADD AN OPTION:
 490  *
 491  * 1. Declare a global variable of type bool, int, double, or char*
 492  *        and make use of it.
 493  *
 494  * 2. Decide at what times it's safe to set the option. See guc.h for
 495  *        details.
 496  *
 497  * 3. Decide on a name, a default value, upper and lower bounds (if
 498  *        applicable), etc.
 499  *
 500  * 4. Add a record below.
 501  *
 502  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 503  *        appropriate.
 504  *
 505  * 6. Don't forget to document the option (at least in config.sgml).
 506  *
 507  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 508  *        it is not single quoted at dump time.
 509  */
 510
 511
 512 /******** option records follow ********/
 513
 514 static struct config_bool ConfigureNamesBool[] =
 515 {
 516         {
 517                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 518                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 519                         NULL
 520                 },
 521                 &enable_seqscan,
 522                 true, NULL, NULL
 523         },
 524         {
 525                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 526                         gettext_noop("Enables the planner's use of index-scan plans."),
 527                         NULL
 528                 },
 529                 &enable_indexscan,
 530                 true, NULL, NULL
 531         },
 532         {
 533                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 534                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 535                         NULL
 536                 },
 537                 &enable_bitmapscan,
 538                 true, NULL, NULL
 539         },
 540         {
 541                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 542                         gettext_noop("Enables the planner's use of TID scan plans."),
 543                         NULL
 544                 },
 545                 &enable_tidscan,
 546                 true, NULL, NULL
 547         },
 548         {
 549                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 550                         gettext_noop("Enables the planner's use of explicit sort steps."),
 551                         NULL
 552                 },
 553                 &enable_sort,
 554                 true, NULL, NULL
 555         },
 556         {
 557                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 558                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 559                         NULL
 560                 },
 561                 &enable_hashagg,
 562                 true, NULL, NULL
 563         },
 564         {
 565                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 566                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 567                         NULL
 568                 },
 569                 &enable_nestloop,
 570                 true, NULL, NULL
 571         },
 572         {
 573                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 574                         gettext_noop("Enables the planner's use of merge join plans."),
 575                         NULL
 576                 },
 577                 &enable_mergejoin,
 578                 true, NULL, NULL
 579         },
 580         {
 581                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 582                         gettext_noop("Enables the planner's use of hash join plans."),
 583                         NULL
 584                 },
 585                 &enable_hashjoin,
 586                 true, NULL, NULL
 587         },
 588         {
 589                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
 590                         gettext_noop("Enables the planner to use constraints to optimize queries."),
 591                         gettext_noop("Child table scans will be skipped if their "
 592                                            "constraints guarantee that no rows match the query.")
 593                 },
 594                 &constraint_exclusion,
 595                 false, NULL, NULL
 596         },
 597         {
 598                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 599                         gettext_noop("Enables genetic query optimization."),
 600                         gettext_noop("This algorithm attempts to do planning without "
 601                                                  "exhaustive searching.")
 602                 },
 603                 &enable_geqo,
 604                 true, NULL, NULL
 605         },
 606         {
 607                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 608                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 609                         gettext_noop("Shows whether the current user is a superuser."),
 610                         NULL,
 611                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 612                 },
 613                 &session_auth_is_superuser,
 614                 false, NULL, NULL
 615         },
 616         {
 617                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 618                         gettext_noop("Enables SSL connections."),
 619                         NULL
 620                 },
 621                 &EnableSSL,
 622                 false, assign_ssl, NULL
 623         },
 624         {
 625                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 626                         gettext_noop("Forces synchronization of updates to disk."),
 627                         gettext_noop("The server will use the fsync() system call in several places to make "
 628                         "sure that updates are physically written to disk. This insures "
 629                                                  "that a database cluster will recover to a consistent state after "
 630                                                  "an operating system or hardware crash.")
 631                 },
 632                 &enableFsync,
 633                 true, NULL, NULL
 634         },
 635         {
 636                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 637                         gettext_noop("Sets immediate fsync at commit."),
 638                         NULL
 639                 },
 640                 &XactSyncCommit,
 641                 true, NULL, NULL
 642         },
 643         {
 644                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 645                         gettext_noop("Continues processing past damaged page headers."),
 646                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 647                                 "report an error, aborting the current transaction. Setting "
 648                                                  "zero_damaged_pages to true causes the system to instead report a "
 649                                                  "warning, zero out the damaged page, and continue processing. This "
 650                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 651                         GUC_NOT_IN_SAMPLE
 652                 },
 653                 &zero_damaged_pages,
 654                 false, NULL, NULL
 655         },
 656         {
 657                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 658                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 659                         gettext_noop("A page write in process during an operating system crash might be "
 660                                                  "only partially written to disk.  During recovery, the row changes "
 661                           "stored in WAL are not enough to recover.  This option writes "
 662                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 663                                                  "is possible.")
 664                 },
 665                 &fullPageWrites,
 666                 true, NULL, NULL
 667         },
 668         {
 669                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHEN,
 670                         gettext_noop("Runs the server silently."),
 671                         gettext_noop("If this parameter is set, the server will automatically run in the "
 672                                  "background and any controlling terminals are dissociated.")
 673                 },
 674                 &SilentMode,
 675                 false, NULL, NULL
 676         },
 677         {
 678                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 679                         gettext_noop("Logs each checkpoint."),
 680                         NULL
 681                 },
 682                 &log_checkpoints,
 683                 false, NULL, NULL
 684         },
 685         {
 686                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 687                         gettext_noop("Logs each successful connection."),
 688                         NULL
 689                 },
 690                 &Log_connections,
 691                 false, NULL, NULL
 692         },
 693         {
 694                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 695                         gettext_noop("Logs end of a session, including duration."),
 696                         NULL
 697                 },
 698                 &Log_disconnections,
 699                 false, NULL, NULL
 700         },
 701         {
 702                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 703                         gettext_noop("Turns on various assertion checks."),
 704                         gettext_noop("This is a debugging aid."),
 705                         GUC_NOT_IN_SAMPLE
 706                 },
 707                 &assert_enabled,
 708 #ifdef USE_ASSERT_CHECKING
 709                 true,
 710 #else
 711                 false,
 712 #endif
 713                 assign_debug_assertions, NULL
 714         },
 715         {
 716                 /* currently undocumented, so don't show in SHOW ALL */
 717                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 718                         gettext_noop("No description available."),
 719                         NULL,
 720                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 721                 },
 722                 &ExitOnAnyError,
 723                 false, NULL, NULL
 724         },
 725         {
 726                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 727                         gettext_noop("Logs the duration of each completed SQL statement."),
 728                         NULL
 729                 },
 730                 &log_duration,
 731                 false, NULL, NULL
 732         },
 733         {
 734                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 735                         gettext_noop("Prints the parse tree to the server log."),
 736                         NULL
 737                 },
 738                 &Debug_print_parse,
 739                 false, NULL, NULL
 740         },
 741         {
 742                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 743                         gettext_noop("Prints the parse tree after rewriting to server log."),
 744                         NULL
 745                 },
 746                 &Debug_print_rewritten,
 747                 false, NULL, NULL
 748         },
 749         {
 750                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 751                         gettext_noop("Prints the execution plan to server log."),
 752                         NULL
 753                 },
 754                 &Debug_print_plan,
 755                 false, NULL, NULL
 756         },
 757         {
 758                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 759                         gettext_noop("Indents parse and plan tree displays."),
 760                         NULL
 761                 },
 762                 &Debug_pretty_print,
 763                 false, NULL, NULL
 764         },
 765         {
 766                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 767                         gettext_noop("Writes parser performance statistics to the server log."),
 768                         NULL
 769                 },
 770                 &log_parser_stats,
 771                 false, assign_stage_log_stats, NULL
 772         },
 773         {
 774                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 775                         gettext_noop("Writes planner performance statistics to the server log."),
 776                         NULL
 777                 },
 778                 &log_planner_stats,
 779                 false, assign_stage_log_stats, NULL
 780         },
 781         {
 782                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 783                         gettext_noop("Writes executor performance statistics to the server log."),
 784                         NULL
 785                 },
 786                 &log_executor_stats,
 787                 false, assign_stage_log_stats, NULL
 788         },
 789         {
 790                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 791                         gettext_noop("Writes cumulative performance statistics to the server log."),
 792                         NULL
 793                 },
 794                 &log_statement_stats,
 795                 false, assign_log_stats, NULL
 796         },
 797 #ifdef BTREE_BUILD_STATS
 798         {
 799                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 800                         gettext_noop("No description available."),
 801                         NULL,
 802                         GUC_NOT_IN_SAMPLE
 803                 },
 804                 &log_btree_build_stats,
 805                 false, NULL, NULL
 806         },
 807 #endif
 808
 809         {
 810                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 811                         gettext_noop("Collects information about executing commands."),
 812                         gettext_noop("Enables the collection of information on the currently "
 813                                                  "executing command of each session, along with "
 814                                                  "the time at which that command began execution.")
 815                 },
 816                 &pgstat_track_activities,
 817                 true, NULL, NULL
 818         },
 819         {
 820                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 821                         gettext_noop("Collects statistics on database activity."),
 822                         NULL
 823                 },
 824                 &pgstat_track_counts,
 825                 true, NULL, NULL
 826         },
 827
 828         {
 829                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 830                         gettext_noop("Updates the process title to show the active SQL command."),
 831                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 832                 },
 833                 &update_process_title,
 834                 true, NULL, NULL
 835         },
 836
 837         {
 838                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 839                         gettext_noop("Starts the autovacuum subprocess."),
 840                         NULL
 841                 },
 842                 &autovacuum_start_daemon,
 843                 true, NULL, NULL
 844         },
 845
 846         {
 847                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 848                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 849                         NULL,
 850                         GUC_NOT_IN_SAMPLE
 851                 },
 852                 &Trace_notify,
 853                 false, NULL, NULL
 854         },
 855
 856 #ifdef LOCK_DEBUG
 857         {
 858                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 859                         gettext_noop("No description available."),
 860                         NULL,
 861                         GUC_NOT_IN_SAMPLE
 862                 },
 863                 &Trace_locks,
 864                 false, NULL, NULL
 865         },
 866         {
 867                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 868                         gettext_noop("No description available."),
 869                         NULL,
 870                         GUC_NOT_IN_SAMPLE
 871                 },
 872                 &Trace_userlocks,
 873                 false, NULL, NULL
 874         },
 875         {
 876                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 877                         gettext_noop("No description available."),
 878                         NULL,
 879                         GUC_NOT_IN_SAMPLE
 880                 },
 881                 &Trace_lwlocks,
 882                 false, NULL, NULL
 883         },
 884         {
 885                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 886                         gettext_noop("No description available."),
 887                         NULL,
 888                         GUC_NOT_IN_SAMPLE
 889                 },
 890                 &Debug_deadlocks,
 891                 false, NULL, NULL
 892         },
 893 #endif
 894
 895         {
 896                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 897                         gettext_noop("Logs long lock waits."),
 898                         NULL
 899                 },
 900                 &log_lock_waits,
 901                 false, NULL, NULL
 902         },
 903
 904         {
 905                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 906                         gettext_noop("Logs the host name in the connection logs."),
 907                         gettext_noop("By default, connection logs only show the IP address "
 908                                                  "of the connecting host. If you want them to show the host name you "
 909                           "can turn this on, but depending on your host name resolution "
 910                            "setup it might impose a non-negligible performance penalty.")
 911                 },
 912                 &log_hostname,
 913                 false, NULL, NULL
 914         },
 915         {
 916                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 917                         gettext_noop("Causes subtables to be included by default in various commands."),
 918                         NULL
 919                 },
 920                 &SQL_inheritance,
 921                 true, NULL, NULL
 922         },
 923         {
 924                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 925                         gettext_noop("Encrypt passwords."),
 926                         gettext_noop("When a password is specified in CREATE USER or "
 927                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 928                                                  "this parameter determines whether the password is to be encrypted.")
 929                 },
 930                 &Password_encryption,
 931                 true, NULL, NULL
 932         },
 933         {
 934                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
 935                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
 936                         gettext_noop("When turned on, expressions of the form expr = NULL "
 937                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
 938                                 "return true if expr evaluates to the null value, and false "
 939                            "otherwise. The correct behavior of expr = NULL is to always "
 940                                                  "return null (unknown).")
 941                 },
 942                 &Transform_null_equals,
 943                 false, NULL, NULL
 944         },
 945         {
 946                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
 947                         gettext_noop("Enables per-database user names."),
 948                         NULL
 949                 },
 950                 &Db_user_namespace,
 951                 false, NULL, NULL
 952         },
 953         {
 954                 /* only here for backwards compatibility */
 955                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
 956                         gettext_noop("This parameter doesn't do anything."),
 957                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
 958                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 959                 },
 960                 &phony_autocommit,
 961                 true, assign_phony_autocommit, NULL
 962         },
 963         {
 964                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
 965                         gettext_noop("Sets the default read-only status of new transactions."),
 966                         NULL
 967                 },
 968                 &DefaultXactReadOnly,
 969                 false, NULL, NULL
 970         },
 971         {
 972                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
 973                         gettext_noop("Sets the current transaction's read-only status."),
 974                         NULL,
 975                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 976                 },
 977                 &XactReadOnly,
 978                 false, assign_transaction_read_only, NULL
 979         },
 980         {
 981                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 982                         gettext_noop("Automatically adds missing table references to FROM clauses."),
 983                         NULL
 984                 },
 985                 &add_missing_from,
 986                 false, NULL, NULL
 987         },
 988         {
 989                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
 990                         gettext_noop("Check function bodies during CREATE FUNCTION."),
 991                         NULL
 992                 },
 993                 &check_function_bodies,
 994                 true, NULL, NULL
 995         },
 996         {
 997                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 998                         gettext_noop("Enable input of NULL elements in arrays."),
 999                         gettext_noop("When turned on, unquoted NULL in an array input "
1000                                                  "value means a null value; "
1001                                                  "otherwise it is taken literally.")
1002                 },
1003                 &Array_nulls,
1004                 true, NULL, NULL
1005         },
1006         {
1007                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1008                         gettext_noop("Create new tables with OIDs by default."),
1009                         NULL
1010                 },
1011                 &default_with_oids,
1012                 false, NULL, NULL
1013         },
1014         {
1015                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1016                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1017                         NULL
1018                 },
1019                 &Logging_collector,
1020                 false, NULL, NULL
1021         },
1022         {
1023                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1024                         gettext_noop("Truncate existing log files of same name during log rotation."),
1025                         NULL
1026                 },
1027                 &Log_truncate_on_rotation,
1028                 false, NULL, NULL
1029         },
1030
1031 #ifdef TRACE_SORT
1032         {
1033                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1034                         gettext_noop("Emit information about resource usage in sorting."),
1035                         NULL,
1036                         GUC_NOT_IN_SAMPLE
1037                 },
1038                 &trace_sort,
1039                 false, NULL, NULL
1040         },
1041 #endif
1042
1043 #ifdef TRACE_SYNCSCAN
1044         /* this is undocumented because not exposed in a standard build */
1045         {
1046                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1047                         gettext_noop("Generate debugging output for synchronized scanning."),
1048                         NULL,
1049                         GUC_NOT_IN_SAMPLE
1050                 },
1051                 &trace_syncscan,
1052                 false, NULL, NULL
1053         },
1054 #endif
1055
1056 #ifdef DEBUG_BOUNDED_SORT
1057         /* this is undocumented because not exposed in a standard build */
1058         {
1059                 {
1060                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1061                         gettext_noop("Enable bounded sorting using heap sort."),
1062                         NULL,
1063                         GUC_NOT_IN_SAMPLE
1064                 },
1065                 &optimize_bounded_sort,
1066                 true, NULL, NULL
1067         },
1068 #endif
1069
1070 #ifdef WAL_DEBUG
1071         {
1072                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1073                         gettext_noop("Emit WAL-related debugging output."),
1074                         NULL,
1075                         GUC_NOT_IN_SAMPLE
1076                 },
1077                 &XLOG_DEBUG,
1078                 false, NULL, NULL
1079         },
1080 #endif
1081
1082         {
1083                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1084                         gettext_noop("Datetimes are integer based."),
1085                         NULL,
1086                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1087                 },
1088                 &integer_datetimes,
1089 #ifdef HAVE_INT64_TIMESTAMP
1090                 true, NULL, NULL
1091 #else
1092                 false, NULL, NULL
1093 #endif
1094         },
1095
1096         {
1097                 {"krb_caseins_users", PGC_POSTMASTER, CONN_AUTH_SECURITY,
1098                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1099                         NULL
1100                 },
1101                 &pg_krb_caseins_users,
1102                 false, NULL, NULL
1103         },
1104
1105         {
1106                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1107                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1108                         NULL
1109                 },
1110                 &escape_string_warning,
1111                 true, NULL, NULL
1112         },
1113
1114         {
1115                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1116                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1117                         NULL,
1118                         GUC_REPORT
1119                 },
1120                 &standard_conforming_strings,
1121                 false, NULL, NULL
1122         },
1123
1124         {
1125                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1126                         gettext_noop("Enable synchronized sequential scans."),
1127                         NULL
1128                 },
1129                 &synchronize_seqscans,
1130                 true, NULL, NULL
1131         },
1132
1133         {
1134                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1135                         gettext_noop("Allows archiving of WAL files using archive_command."),
1136                         NULL
1137                 },
1138                 &XLogArchiveMode,
1139                 false, NULL, NULL
1140         },
1141
1142         {
1143                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1144                         gettext_noop("Allows modifications of the structure of system tables."),
1145                         NULL,
1146                         GUC_NOT_IN_SAMPLE
1147                 },
1148                 &allowSystemTableMods,
1149                 false, NULL, NULL
1150         },
1151
1152         {
1153                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1154                         gettext_noop("Disables reading from system indexes."),
1155                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1156                                                  "to use.  The worst consequence is slowness."),
1157                         GUC_NOT_IN_SAMPLE
1158                 },
1159                 &IgnoreSystemIndexes,
1160                 false, NULL, NULL
1161         },
1162
1163         /* End-of-list marker */
1164         {
1165                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1166         }
1167 };
1168
1169
1170 static struct config_int ConfigureNamesInt[] =
1171 {
1172         {
1173                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1174                         gettext_noop("Forces a switch to the next xlog file if a "
1175                                                  "new file has not been started within N seconds."),
1176                         NULL,
1177                         GUC_UNIT_S
1178                 },
1179                 &XLogArchiveTimeout,
1180                 0, 0, INT_MAX, NULL, NULL
1181         },
1182         {
1183                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1184                         gettext_noop("Waits N seconds on connection startup after authentication."),
1185                         gettext_noop("This allows attaching a debugger to the process."),
1186                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1187                 },
1188                 &PostAuthDelay,
1189                 0, 0, INT_MAX, NULL, NULL
1190         },
1191         {
1192                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1193                         gettext_noop("Sets the default statistics target."),
1194                         gettext_noop("This applies to table columns that have not had a "
1195                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1196                 },
1197                 &default_statistics_target,
1198                 10, 1, 1000, NULL, NULL
1199         },
1200         {
1201                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1202                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1203                                                  "are not collapsed."),
1204                         gettext_noop("The planner will merge subqueries into upper "
1205                                 "queries if the resulting FROM list would have no more than "
1206                                                  "this many items.")
1207                 },
1208                 &from_collapse_limit,
1209                 8, 1, INT_MAX, NULL, NULL
1210         },
1211         {
1212                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1213                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1214                                                  "constructs are not flattened."),
1215                         gettext_noop("The planner will flatten explicit JOIN "
1216                                                  "constructs into lists of FROM items whenever a "
1217                                                  "list of no more than this many items would result.")
1218                 },
1219                 &join_collapse_limit,
1220                 8, 1, INT_MAX, NULL, NULL
1221         },
1222         {
1223                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1224                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1225                         NULL
1226                 },
1227                 &geqo_threshold,
1228                 12, 2, INT_MAX, NULL, NULL
1229         },
1230         {
1231                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1232                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1233                         NULL
1234                 },
1235                 &Geqo_effort,
1236                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1237         },
1238         {
1239                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1240                         gettext_noop("GEQO: number of individuals in the population."),
1241                         gettext_noop("Zero selects a suitable default value.")
1242                 },
1243                 &Geqo_pool_size,
1244                 0, 0, INT_MAX, NULL, NULL
1245         },
1246         {
1247                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1248                         gettext_noop("GEQO: number of iterations of the algorithm."),
1249                         gettext_noop("Zero selects a suitable default value.")
1250                 },
1251                 &Geqo_generations,
1252                 0, 0, INT_MAX, NULL, NULL
1253         },
1254
1255         {
1256                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1257                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1258                         NULL,
1259                         GUC_UNIT_MS
1260                 },
1261                 &DeadlockTimeout,
1262                 1000, 1, INT_MAX / 1000, NULL, NULL
1263         },
1264
1265         /*
1266          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1267          * 4*MaxBackends without any overflow check.  This check is made in
1268          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1269          * plus autovacuum_max_workers.
1270          *
1271          * Likewise we have to limit NBuffers to INT_MAX/2.
1272          */
1273         {
1274                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1275                         gettext_noop("Sets the maximum number of concurrent connections."),
1276                         NULL
1277                 },
1278                 &MaxConnections,
1279                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1280         },
1281
1282         {
1283                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1284                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1285                         NULL
1286                 },
1287                 &ReservedBackends,
1288                 3, 0, INT_MAX / 4, NULL, NULL
1289         },
1290
1291         {
1292                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1293                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1294                         NULL,
1295                         GUC_UNIT_BLOCKS
1296                 },
1297                 &NBuffers,
1298                 1024, 16, INT_MAX / 2, NULL, NULL
1299         },
1300
1301         {
1302                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1303                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1304                         NULL,
1305                         GUC_UNIT_BLOCKS
1306                 },
1307                 &num_temp_buffers,
1308                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1309         },
1310
1311         {
1312                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1313                         gettext_noop("Sets the TCP port the server listens on."),
1314                         NULL
1315                 },
1316                 &PostPortNumber,
1317                 DEF_PGPORT, 1, 65535, NULL, NULL
1318         },
1319
1320         {
1321                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1322                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1323                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1324                                                  "permission set. The parameter value is expected to be an numeric mode "
1325                                                  "specification in the form accepted by the chmod and umask system "
1326                                                  "calls. (To use the customary octal format the number must start with "
1327                                                  "a 0 (zero).)")
1328                 },
1329                 &Unix_socket_permissions,
1330                 0777, 0000, 0777, NULL, NULL
1331         },
1332
1333         {
1334                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1335                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1336                         gettext_noop("This much memory can be used by each internal "
1337                                                  "sort operation and hash table before switching to "
1338                                                  "temporary disk files."),
1339                         GUC_UNIT_KB
1340                 },
1341                 &work_mem,
1342                 1024, 8 * BLCKSZ / 1024, MAX_KILOBYTES, NULL, NULL
1343         },
1344
1345         {
1346                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1347                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1348                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1349                         GUC_UNIT_KB
1350                 },
1351                 &maintenance_work_mem,
1352                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1353         },
1354
1355         {
1356                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1357                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1358                         NULL,
1359                         GUC_UNIT_KB
1360                 },
1361                 &max_stack_depth,
1362                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1363         },
1364
1365         {
1366                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1367                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1368                         NULL
1369                 },
1370                 &VacuumCostPageHit,
1371                 1, 0, 10000, NULL, NULL
1372         },
1373
1374         {
1375                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1376                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1377                         NULL
1378                 },
1379                 &VacuumCostPageMiss,
1380                 10, 0, 10000, NULL, NULL
1381         },
1382
1383         {
1384                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1385                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1386                         NULL
1387                 },
1388                 &VacuumCostPageDirty,
1389                 20, 0, 10000, NULL, NULL
1390         },
1391
1392         {
1393                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1394                         gettext_noop("Vacuum cost amount available before napping."),
1395                         NULL
1396                 },
1397                 &VacuumCostLimit,
1398                 200, 1, 10000, NULL, NULL
1399         },
1400
1401         {
1402                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1403                         gettext_noop("Vacuum cost delay in milliseconds."),
1404                         NULL,
1405                         GUC_UNIT_MS
1406                 },
1407                 &VacuumCostDelay,
1408                 0, 0, 1000, NULL, NULL
1409         },
1410
1411         {
1412                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1413                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1414                         NULL,
1415                         GUC_UNIT_MS
1416                 },
1417                 &autovacuum_vac_cost_delay,
1418                 20, -1, 1000, NULL, NULL
1419         },
1420
1421         {
1422                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1423                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1424                         NULL
1425                 },
1426                 &autovacuum_vac_cost_limit,
1427                 -1, -1, 10000, NULL, NULL
1428         },
1429
1430         {
1431                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1432                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1433                         NULL
1434                 },
1435                 &max_files_per_process,
1436                 1000, 25, INT_MAX, NULL, NULL
1437         },
1438
1439         {
1440                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1441                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1442                         NULL
1443                 },
1444                 &max_prepared_xacts,
1445                 5, 0, INT_MAX, NULL, NULL
1446         },
1447
1448 #ifdef LOCK_DEBUG
1449         {
1450                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1451                         gettext_noop("No description available."),
1452                         NULL,
1453                         GUC_NOT_IN_SAMPLE
1454                 },
1455                 &Trace_lock_oidmin,
1456                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1457         },
1458         {
1459                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1460                         gettext_noop("No description available."),
1461                         NULL,
1462                         GUC_NOT_IN_SAMPLE
1463                 },
1464                 &Trace_lock_table,
1465                 0, 0, INT_MAX, NULL, NULL
1466         },
1467 #endif
1468
1469         {
1470                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1471                         gettext_noop("Sets the maximum allowed duration of any statement."),
1472                         gettext_noop("A value of 0 turns off the timeout."),
1473                         GUC_UNIT_MS
1474                 },
1475                 &StatementTimeout,
1476                 0, 0, INT_MAX, NULL, NULL
1477         },
1478
1479         {
1480                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1481                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1482                         NULL
1483                 },
1484                 &vacuum_freeze_min_age,
1485                 100000000, 0, 1000000000, NULL, NULL
1486         },
1487
1488         {
1489                 {"max_fsm_relations", PGC_POSTMASTER, RESOURCES_FSM,
1490                         gettext_noop("Sets the maximum number of tables and indexes for which free space is tracked."),
1491                         NULL
1492                 },
1493                 &MaxFSMRelations,
1494                 1000, 100, INT_MAX, NULL, NULL
1495         },
1496         {
1497                 {"max_fsm_pages", PGC_POSTMASTER, RESOURCES_FSM,
1498                         gettext_noop("Sets the maximum number of disk pages for which free space is tracked."),
1499                         NULL
1500                 },
1501                 &MaxFSMPages,
1502                 20000, 1000, INT_MAX, NULL, NULL
1503         },
1504
1505         {
1506                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1507                         gettext_noop("Sets the maximum number of locks per transaction."),
1508                         gettext_noop("The shared lock table is sized on the assumption that "
1509                           "at most max_locks_per_transaction * max_connections distinct "
1510                                                  "objects will need to be locked at any one time.")
1511                 },
1512                 &max_locks_per_xact,
1513                 64, 10, INT_MAX, NULL, NULL
1514         },
1515
1516         {
1517                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1518                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1519                         NULL,
1520                         GUC_UNIT_S
1521                 },
1522                 &AuthenticationTimeout,
1523                 60, 1, 600, NULL, NULL
1524         },
1525
1526         {
1527                 /* Not for general use */
1528                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1529                         gettext_noop("Waits N seconds on connection startup before authentication."),
1530                         gettext_noop("This allows attaching a debugger to the process."),
1531                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1532                 },
1533                 &PreAuthDelay,
1534                 0, 0, 60, NULL, NULL
1535         },
1536
1537         {
1538                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1539                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1540                         NULL
1541                 },
1542                 &CheckPointSegments,
1543                 3, 1, INT_MAX, NULL, NULL
1544         },
1545
1546         {
1547                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1548                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1549                         NULL,
1550                         GUC_UNIT_S
1551                 },
1552                 &CheckPointTimeout,
1553                 300, 30, 3600, NULL, NULL
1554         },
1555
1556         {
1557                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1558                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1559                                                  "frequently than this."),
1560                         gettext_noop("Write a message to the server log if checkpoints "
1561                         "caused by the filling of checkpoint segment files happens more "
1562                                                  "frequently than this number of seconds. Zero turns off the warning."),
1563                         GUC_UNIT_S
1564                 },
1565                 &CheckPointWarning,
1566                 30, 0, INT_MAX, NULL, NULL
1567         },
1568
1569         {
1570                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1571                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1572                         NULL,
1573                         GUC_UNIT_XBLOCKS
1574                 },
1575                 &XLOGbuffers,
1576                 8, 4, INT_MAX, NULL, NULL
1577         },
1578
1579         {
1580                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1581                         gettext_noop("WAL writer sleep time between WAL flushes."),
1582                         NULL,
1583                         GUC_UNIT_MS
1584                 },
1585                 &WalWriterDelay,
1586                 200, 1, 10000, NULL, NULL
1587         },
1588
1589         {
1590                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1591                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1592                                                  "flushing WAL to disk."),
1593                         NULL
1594                 },
1595                 &CommitDelay,
1596                 0, 0, 100000, NULL, NULL
1597         },
1598
1599         {
1600                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1601                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1602                                                  "commit_delay."),
1603                         NULL
1604                 },
1605                 &CommitSiblings,
1606                 5, 1, 1000, NULL, NULL
1607         },
1608
1609         {
1610                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1611                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1612                         gettext_noop("This affects real, double precision, and geometric data types. "
1613                          "The parameter value is added to the standard number of digits "
1614                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1615                 },
1616                 &extra_float_digits,
1617                 0, -15, 2, NULL, NULL
1618         },
1619
1620         {
1621                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1622                         gettext_noop("Sets the minimum execution time above which "
1623                                                  "statements will be logged."),
1624                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1625                         GUC_UNIT_MS
1626                 },
1627                 &log_min_duration_statement,
1628                 -1, -1, INT_MAX / 1000, NULL, NULL
1629         },
1630
1631         {
1632                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1633                         gettext_noop("Sets the minimum execution time above which "
1634                                                  "autovacuum actions will be logged."),
1635                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1636                         GUC_UNIT_MS
1637                 },
1638                 &Log_autovacuum_min_duration,
1639                 -1, -1, INT_MAX / 1000, NULL, NULL
1640         },
1641
1642         {
1643                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1644                         gettext_noop("Background writer sleep time between rounds."),
1645                         NULL,
1646                         GUC_UNIT_MS
1647                 },
1648                 &BgWriterDelay,
1649                 200, 10, 10000, NULL, NULL
1650         },
1651
1652         {
1653                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1654                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1655                         NULL
1656                 },
1657                 &bgwriter_lru_maxpages,
1658                 100, 0, 1000, NULL, NULL
1659         },
1660
1661         {
1662                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1663                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1664                         NULL,
1665                         GUC_UNIT_MIN
1666                 },
1667                 &Log_RotationAge,
1668                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1669         },
1670
1671         {
1672                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1673                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1674                         NULL,
1675                         GUC_UNIT_KB
1676                 },
1677                 &Log_RotationSize,
1678                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1679         },
1680
1681         {
1682                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1683                         gettext_noop("Shows the maximum number of function arguments."),
1684                         NULL,
1685                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1686                 },
1687                 &max_function_args,
1688                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1689         },
1690
1691         {
1692                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1693                         gettext_noop("Shows the maximum number of index keys."),
1694                         NULL,
1695                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1696                 },
1697                 &max_index_keys,
1698                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1699         },
1700
1701         {
1702                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1703                         gettext_noop("Shows the maximum identifier length."),
1704                         NULL,
1705                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1706                 },
1707                 &max_identifier_length,
1708                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1709         },
1710
1711         {
1712                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1713                         gettext_noop("Shows the size of a disk block."),
1714                         NULL,
1715                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1716                 },
1717                 &block_size,
1718                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1719         },
1720
1721         {
1722                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1723                         gettext_noop("Time to sleep between autovacuum runs."),
1724                         NULL,
1725                         GUC_UNIT_S
1726                 },
1727                 &autovacuum_naptime,
1728                 60, 1, INT_MAX / 1000, NULL, NULL
1729         },
1730         {
1731                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1732                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1733                         NULL
1734                 },
1735                 &autovacuum_vac_thresh,
1736                 50, 0, INT_MAX, NULL, NULL
1737         },
1738         {
1739                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1740                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1741                         NULL
1742                 },
1743                 &autovacuum_anl_thresh,
1744                 50, 0, INT_MAX, NULL, NULL
1745         },
1746         {
1747                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1748                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1749                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1750                         NULL
1751                 },
1752                 &autovacuum_freeze_max_age,
1753                 200000000, 100000000, 2000000000, NULL, NULL
1754         },
1755         {
1756                 /* see max_connections */
1757                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1758                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1759                         NULL
1760                 },
1761                 &autovacuum_max_workers,
1762                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1763         },
1764
1765         {
1766                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1767                         gettext_noop("Time between issuing TCP keepalives."),
1768                         gettext_noop("A value of 0 uses the system default."),
1769                         GUC_UNIT_S
1770                 },
1771                 &tcp_keepalives_idle,
1772                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1773         },
1774
1775         {
1776                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1777                         gettext_noop("Time between TCP keepalive retransmits."),
1778                         gettext_noop("A value of 0 uses the system default."),
1779                         GUC_UNIT_S
1780                 },
1781                 &tcp_keepalives_interval,
1782                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1783         },
1784
1785         {
1786                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1787                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1788                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1789                                                  "lost before a connection is considered dead. A value of 0 uses the "
1790                                                  "system default."),
1791                 },
1792                 &tcp_keepalives_count,
1793                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1794         },
1795
1796         {
1797                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1798                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1799                         NULL,
1800                         0
1801                 },
1802                 &GinFuzzySearchLimit,
1803                 0, 0, INT_MAX, NULL, NULL
1804         },
1805
1806         {
1807                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1808                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1809                         gettext_noop("That is, the portion of the kernel's disk cache that "
1810                                                  "will be used for PostgreSQL data files. This is measured in disk "
1811                                                  "pages, which are normally 8 kB each."),
1812                         GUC_UNIT_BLOCKS,
1813                 },
1814                 &effective_cache_size,
1815                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1816         },
1817
1818         {
1819                 /* Can't be set in postgresql.conf */
1820                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1821                         gettext_noop("Shows the server version as an integer."),
1822                         NULL,
1823                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1824                 },
1825                 &server_version_num,
1826                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1827         },
1828
1829         {
1830                 {"log_temp_files", PGC_USERSET, LOGGING_WHAT,
1831                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1832                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1833                         GUC_UNIT_KB
1834                 },
1835                 &log_temp_files,
1836                 -1, -1, INT_MAX, NULL, NULL
1837         },
1838
1839         /* End-of-list marker */
1840         {
1841                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1842         }
1843 };
1844
1845
1846 static struct config_real ConfigureNamesReal[] =
1847 {
1848         {
1849                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1850                         gettext_noop("Sets the planner's estimate of the cost of a "
1851                                                  "sequentially fetched disk page."),
1852                         NULL
1853                 },
1854                 &seq_page_cost,
1855                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1856         },
1857         {
1858                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1859                         gettext_noop("Sets the planner's estimate of the cost of a "
1860                                                  "nonsequentially fetched disk page."),
1861                         NULL
1862                 },
1863                 &random_page_cost,
1864                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1865         },
1866         {
1867                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1868                         gettext_noop("Sets the planner's estimate of the cost of "
1869                                                  "processing each tuple (row)."),
1870                         NULL
1871                 },
1872                 &cpu_tuple_cost,
1873                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1874         },
1875         {
1876                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1877                         gettext_noop("Sets the planner's estimate of the cost of "
1878                                                  "processing each index entry during an index scan."),
1879                         NULL
1880                 },
1881                 &cpu_index_tuple_cost,
1882                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1883         },
1884         {
1885                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
1886                         gettext_noop("Sets the planner's estimate of the cost of "
1887                                                  "processing each operator or function call."),
1888                         NULL
1889                 },
1890                 &cpu_operator_cost,
1891                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
1892         },
1893
1894         {
1895                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
1896                         gettext_noop("GEQO: selective pressure within the population."),
1897                         NULL
1898                 },
1899                 &Geqo_selection_bias,
1900                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
1901                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
1902         },
1903
1904         {
1905                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
1906                         gettext_noop("Multiple of the average buffer usage to free per round."),
1907                         NULL
1908                 },
1909                 &bgwriter_lru_multiplier,
1910                 2.0, 0.0, 10.0, NULL, NULL
1911         },
1912
1913         {
1914                 {"seed", PGC_USERSET, UNGROUPED,
1915                         gettext_noop("Sets the seed for random-number generation."),
1916                         NULL,
1917                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1918                 },
1919                 &phony_random_seed,
1920                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
1921         },
1922
1923         {
1924                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
1925                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
1926                         NULL
1927                 },
1928                 &autovacuum_vac_scale,
1929                 0.2, 0.0, 100.0, NULL, NULL
1930         },
1931         {
1932                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
1933                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
1934                         NULL
1935                 },
1936                 &autovacuum_anl_scale,
1937                 0.1, 0.0, 100.0, NULL, NULL
1938         },
1939
1940         {
1941                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
1942                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
1943                         NULL
1944                 },
1945                 &CheckPointCompletionTarget,
1946                 0.5, 0.0, 1.0, NULL, NULL
1947         },
1948
1949         /* End-of-list marker */
1950         {
1951                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
1952         }
1953 };
1954
1955
1956 static struct config_string ConfigureNamesString[] =
1957 {
1958         {
1959                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
1960                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
1961                         NULL
1962                 },
1963                 &XLogArchiveCommand,
1964                 "", NULL, show_archive_command
1965         },
1966
1967         {
1968                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
1969                         gettext_noop("Sets the client's character set encoding."),
1970                         NULL,
1971                         GUC_IS_NAME | GUC_REPORT
1972                 },
1973                 &client_encoding_string,
1974                 "SQL_ASCII", assign_client_encoding, NULL
1975         },
1976
1977         {
1978                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
1979                         gettext_noop("Controls information prefixed to each log line."),
1980                         gettext_noop("If blank, no prefix is used.")
1981                 },
1982                 &Log_line_prefix,
1983                 "", NULL, NULL
1984         },
1985
1986         {
1987                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
1988                         gettext_noop("Sets the time zone to use in log messages."),
1989                         NULL
1990                 },
1991                 &log_timezone_string,
1992                 "UNKNOWN", assign_log_timezone, show_log_timezone
1993         },
1994
1995         {
1996                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
1997                         gettext_noop("Sets the display format for date and time values."),
1998                         gettext_noop("Also controls interpretation of ambiguous "
1999                                                  "date inputs."),
2000                         GUC_LIST_INPUT | GUC_REPORT
2001                 },
2002                 &datestyle_string,
2003                 "ISO, MDY", assign_datestyle, NULL
2004         },
2005
2006         {
2007                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2008                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2009                         gettext_noop("An empty string selects the database's default tablespace."),
2010                         GUC_IS_NAME
2011                 },
2012                 &default_tablespace,
2013                 "", assign_default_tablespace, NULL
2014         },
2015
2016         {
2017                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2018                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2019                         NULL,
2020                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2021                 },
2022                 &temp_tablespaces,
2023                 "", assign_temp_tablespaces, NULL
2024         },
2025
2026         {
2027                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2028                         gettext_noop("Sets the path for dynamically loadable modules."),
2029                         gettext_noop("If a dynamically loadable module needs to be opened and "
2030                                                  "the specified name does not have a directory component (i.e., the "
2031                                                  "name does not contain a slash), the system will search this path for "
2032                                                  "the specified file."),
2033                         GUC_SUPERUSER_ONLY
2034                 },
2035                 &Dynamic_library_path,
2036                 "$libdir", NULL, NULL
2037         },
2038
2039         {
2040                 {"krb_realm", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2041                         gettext_noop("Sets realm to match Kerberos and GSSAPI users against."),
2042                         NULL,
2043                         GUC_SUPERUSER_ONLY
2044                 },
2045                 &pg_krb_realm,
2046                 NULL, NULL, NULL
2047         },
2048
2049         {
2050                 {"krb_server_keyfile", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2051                         gettext_noop("Sets the location of the Kerberos server key file."),
2052                         NULL,
2053                         GUC_SUPERUSER_ONLY
2054                 },
2055                 &pg_krb_server_keyfile,
2056                 PG_KRB_SRVTAB, NULL, NULL
2057         },
2058
2059         {
2060                 {"krb_srvname", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2061                         gettext_noop("Sets the name of the Kerberos service."),
2062                         NULL
2063                 },
2064                 &pg_krb_srvnam,
2065                 PG_KRB_SRVNAM, NULL, NULL
2066         },
2067
2068         {
2069                 {"krb_server_hostname", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2070                         gettext_noop("Sets the hostname of the Kerberos server."),
2071                         NULL
2072                 },
2073                 &pg_krb_server_hostname,
2074                 NULL, NULL, NULL
2075         },
2076
2077         {
2078                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2079                         gettext_noop("Sets the Bonjour broadcast service name."),
2080                         NULL
2081                 },
2082                 &bonjour_name,
2083                 "", NULL, NULL
2084         },
2085
2086         /* See main.c about why defaults for LC_foo are not all alike */
2087
2088         {
2089                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2090                         gettext_noop("Shows the collation order locale."),
2091                         NULL,
2092                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2093                 },
2094                 &locale_collate,
2095                 "C", NULL, NULL
2096         },
2097
2098         {
2099                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2100                         gettext_noop("Shows the character classification and case conversion locale."),
2101                         NULL,
2102                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2103                 },
2104                 &locale_ctype,
2105                 "C", NULL, NULL
2106         },
2107
2108         {
2109                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2110                         gettext_noop("Sets the language in which messages are displayed."),
2111                         NULL
2112                 },
2113                 &locale_messages,
2114                 "", locale_messages_assign, NULL
2115         },
2116
2117         {
2118                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2119                         gettext_noop("Sets the locale for formatting monetary amounts."),
2120                         NULL
2121                 },
2122                 &locale_monetary,
2123                 "C", locale_monetary_assign, NULL
2124         },
2125
2126         {
2127                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2128                         gettext_noop("Sets the locale for formatting numbers."),
2129                         NULL
2130                 },
2131                 &locale_numeric,
2132                 "C", locale_numeric_assign, NULL
2133         },
2134
2135         {
2136                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2137                         gettext_noop("Sets the locale for formatting date and time values."),
2138                         NULL
2139                 },
2140                 &locale_time,
2141                 "C", locale_time_assign, NULL
2142         },
2143
2144         {
2145                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2146                         gettext_noop("Lists shared libraries to preload into server."),
2147                         NULL,
2148                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2149                 },
2150                 &shared_preload_libraries_string,
2151                 "", NULL, NULL
2152         },
2153
2154         {
2155                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2156                         gettext_noop("Lists shared libraries to preload into each backend."),
2157                         NULL,
2158                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2159                 },
2160                 &local_preload_libraries_string,
2161                 "", NULL, NULL
2162         },
2163
2164         {
2165                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2166                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2167                         NULL,
2168                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2169                 },
2170                 &namespace_search_path,
2171                 "\"$user\",public", assign_search_path, NULL
2172         },
2173
2174         {
2175                 /* Can't be set in postgresql.conf */
2176                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2177                         gettext_noop("Sets the server (database) character set encoding."),
2178                         NULL,
2179                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2180                 },
2181                 &server_encoding_string,
2182                 "SQL_ASCII", NULL, NULL
2183         },
2184
2185         {
2186                 /* Can't be set in postgresql.conf */
2187                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2188                         gettext_noop("Shows the server version."),
2189                         NULL,
2190                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2191                 },
2192                 &server_version_string,
2193                 PG_VERSION, NULL, NULL
2194         },
2195
2196         {
2197                 /* Not for general use --- used by SET ROLE */
2198                 {"role", PGC_USERSET, UNGROUPED,
2199                         gettext_noop("Sets the current role."),
2200                         NULL,
2201                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2202                 },
2203                 &role_string,
2204                 "none", assign_role, show_role
2205         },
2206
2207         {
2208                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2209                 {"session_authorization", PGC_USERSET, UNGROUPED,
2210                         gettext_noop("Sets the session user name."),
2211                         NULL,
2212                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2213                 },
2214                 &session_authorization_string,
2215                 NULL, assign_session_authorization, show_session_authorization
2216         },
2217
2218         {
2219                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2220                         gettext_noop("Sets the destination for server log output."),
2221                         gettext_noop("Valid values are combinations of \"stderr\", "
2222                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2223                                                  "depending on the platform."),
2224                         GUC_LIST_INPUT
2225                 },
2226                 &log_destination_string,
2227                 "stderr", assign_log_destination, NULL
2228         },
2229         {
2230                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2231                         gettext_noop("Sets the destination directory for log files."),
2232                         gettext_noop("Can be specified as relative to the data directory "
2233                                                  "or as absolute path."),
2234                         GUC_SUPERUSER_ONLY
2235                 },
2236                 &Log_directory,
2237                 "pg_log", assign_canonical_path, NULL
2238         },
2239         {
2240                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2241                         gettext_noop("Sets the file name pattern for log files."),
2242                         NULL,
2243                         GUC_SUPERUSER_ONLY
2244                 },
2245                 &Log_filename,
2246                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2247         },
2248
2249 #ifdef HAVE_SYSLOG
2250         {
2251                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2252                         gettext_noop("Sets the program name used to identify PostgreSQL "
2253                                                  "messages in syslog."),
2254                         NULL
2255                 },
2256                 &syslog_ident_str,
2257                 "postgres", assign_syslog_ident, NULL
2258         },
2259 #endif
2260
2261         {
2262                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2263                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2264                         NULL,
2265                         GUC_REPORT
2266                 },
2267                 &timezone_string,
2268                 "UNKNOWN", assign_timezone, show_timezone
2269         },
2270         {
2271                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2272                         gettext_noop("Selects a file of time zone abbreviations."),
2273                         NULL,
2274                 },
2275                 &timezone_abbreviations_string,
2276                 "UNKNOWN", assign_timezone_abbreviations, NULL
2277         },
2278
2279         {
2280                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2281                         gettext_noop("Sets the current transaction's isolation level."),
2282                         NULL,
2283                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2284                 },
2285                 &XactIsoLevel_string,
2286                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2287         },
2288
2289         {
2290                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2291                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2292                         gettext_noop("The owning user of the socket is always the user "
2293                                                  "that starts the server.")
2294                 },
2295                 &Unix_socket_group,
2296                 "", NULL, NULL
2297         },
2298
2299         {
2300                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2301                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2302                         NULL,
2303                         GUC_SUPERUSER_ONLY
2304                 },
2305                 &UnixSocketDir,
2306                 "", assign_canonical_path, NULL
2307         },
2308
2309         {
2310                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2311                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2312                         NULL,
2313                         GUC_LIST_INPUT
2314                 },
2315                 &ListenAddresses,
2316                 "localhost", NULL, NULL
2317         },
2318
2319         {
2320                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2321                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2322                         NULL
2323                 },
2324                 &XLOG_sync_method,
2325                 XLOG_sync_method_default, assign_xlog_sync_method, NULL
2326         },
2327
2328         {
2329                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2330                         gettext_noop("Sets the list of known custom variable classes."),
2331                         NULL,
2332                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2333                 },
2334                 &custom_variable_classes,
2335                 NULL, assign_custom_variable_classes, NULL
2336         },
2337
2338         {
2339                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2340                         gettext_noop("Sets the server's data directory."),
2341                         NULL,
2342                         GUC_SUPERUSER_ONLY
2343                 },
2344                 &data_directory,
2345                 NULL, NULL, NULL
2346         },
2347
2348         {
2349                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2350                         gettext_noop("Sets the server's main configuration file."),
2351                         NULL,
2352                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2353                 },
2354                 &ConfigFileName,
2355                 NULL, NULL, NULL
2356         },
2357
2358         {
2359                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2360                         gettext_noop("Sets the server's \"hba\" configuration file."),
2361                         NULL,
2362                         GUC_SUPERUSER_ONLY
2363                 },
2364                 &HbaFileName,
2365                 NULL, NULL, NULL
2366         },
2367
2368         {
2369                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2370                         gettext_noop("Sets the server's \"ident\" configuration file."),
2371                         NULL,
2372                         GUC_SUPERUSER_ONLY
2373                 },
2374                 &IdentFileName,
2375                 NULL, NULL, NULL
2376         },
2377
2378         {
2379                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2380                         gettext_noop("Writes the postmaster PID to the specified file."),
2381                         NULL,
2382                         GUC_SUPERUSER_ONLY
2383                 },
2384                 &external_pid_file,
2385                 NULL, assign_canonical_path, NULL
2386         },
2387
2388         {
2389                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2390                         gettext_noop("Sets default text search configuration."),
2391                         NULL
2392                 },
2393                 &TSCurrentConfig,
2394                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2395         },
2396
2397 #ifdef USE_SSL
2398         {
2399                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2400                         gettext_noop("Sets the list of allowed SSL ciphers."),
2401                         NULL,
2402                         GUC_SUPERUSER_ONLY
2403                 },
2404                 &SSLCipherSuites,
2405                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2406         },
2407 #endif   /* USE_SSL */
2408
2409         /* End-of-list marker */
2410         {
2411                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2412         }
2413 };
2414
2415
2416 static struct config_enum ConfigureNamesEnum[] =
2417 {
2418         {
2419                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2420                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2421                         gettext_noop("Valid values are ON, OFF, and SAFE_ENCODING.")
2422                 },
2423                 &backslash_quote,
2424                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2425         },
2426
2427         {
2428                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2429                         gettext_noop("Sets the message levels that are sent to the client."),
2430                         gettext_noop("Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, "
2431                                                  "DEBUG1, LOG, NOTICE, WARNING, and ERROR. Each level includes all the "
2432                                                  "levels that follow it. The later the level, the fewer messages are "
2433                                                  "sent.")
2434                 },
2435                 &client_min_messages,
2436                 NOTICE, message_level_options,NULL, NULL
2437         },
2438
2439         {
2440                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2441                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2442                         gettext_noop("Each SQL transaction has an isolation level, which "
2443                                                  "can be either \"read uncommitted\", \"read committed\", \"repeatable read\", or \"serializable\".")
2444                 },
2445                 &DefaultXactIsoLevel,
2446                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2447         },
2448
2449         {
2450                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2451                         gettext_noop("Sets the verbosity of logged messages."),
2452                         gettext_noop("Valid values are \"terse\", \"default\", and \"verbose\".")
2453                 },
2454                 &Log_error_verbosity,
2455                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2456         },
2457
2458         {
2459                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2460                         gettext_noop("Sets the message levels that are logged."),
2461                         gettext_noop("Valid values are DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1, "
2462                         "INFO, NOTICE, WARNING, ERROR, LOG, FATAL, and PANIC. Each level "
2463                                                  "includes all the levels that follow it.")
2464                 },
2465                 &log_min_messages,
2466                 WARNING, message_level_options, NULL, NULL
2467         },
2468
2469         {
2470                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2471                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2472                         gettext_noop("All SQL statements that cause an error of the "
2473                                                  "specified level or a higher level are logged.")
2474                 },
2475                 &log_min_error_statement,
2476                 ERROR, message_level_options, NULL, NULL
2477         },
2478
2479         {
2480                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2481                         gettext_noop("Sets the type of statements logged."),
2482                         gettext_noop("Valid values are \"none\", \"ddl\", \"mod\", and \"all\".")
2483                 },
2484                 &log_statement,
2485                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2486         },
2487
2488 #ifdef HAVE_SYSLOG
2489         {
2490                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2491                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2492                         gettext_noop("Valid values are LOCAL0, LOCAL1, LOCAL2, LOCAL3, "
2493                                                  "LOCAL4, LOCAL5, LOCAL6, LOCAL7.")
2494                 },
2495                 &syslog_facility,
2496                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2497         },
2498 #endif
2499
2500         {
2501                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2502                         gettext_noop("Sets the regular expression \"flavor\"."),
2503                         gettext_noop("This can be set to advanced, extended, or basic.")
2504                 },
2505                 &regex_flavor,
2506                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2507         },
2508
2509         {
2510                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2511                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2512                         gettext_noop("Each session can be either"
2513                                                  " \"origin\", \"replica\", or \"local\".")
2514                 },
2515                 &SessionReplicationRole,
2516                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2517                 assign_session_replication_role, NULL
2518         },
2519
2520         {
2521                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2522                         gettext_noop("Sets how binary values are to be encoded in XML."),
2523                         gettext_noop("Valid values are BASE64 and HEX.")
2524                 },
2525                 &xmlbinary,
2526                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2527         },
2528
2529         {
2530                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2531                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2532                                                  "operations is to be considered as documents or content fragments."),
2533                         gettext_noop("Valid values are DOCUMENT and CONTENT.")
2534                 },
2535                 &xmloption,
2536                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2537         },
2538
2539
2540         /* End-of-list marker */
2541         {
2542                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2543         }
2544 };
2545
2546 /******** end of options list ********/
2547
2548
2549 /*
2550  * To allow continued support of obsolete names for GUC variables, we apply
2551  * the following mappings to any unrecognized name.  Note that an old name
2552  * should be mapped to a new one only if the new variable has very similar
2553  * semantics to the old.
2554  */
2555 static const char *const map_old_guc_names[] = {
2556         "sort_mem", "work_mem",
2557         "vacuum_mem", "maintenance_work_mem",
2558         NULL
2559 };
2560
2561
2562 /*
2563  * Actual lookup of variables is done through this single, sorted array.
2564  */
2565 static struct config_generic **guc_variables;
2566
2567 /* Current number of variables contained in the vector */
2568 static int      num_guc_variables;
2569
2570 /* Vector capacity */
2571 static int      size_guc_variables;
2572
2573
2574 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2575
2576 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2577
2578 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2579
2580
2581 static int      guc_var_compare(const void *a, const void *b);
2582 static int      guc_name_compare(const char *namea, const char *nameb);
2583 static void push_old_value(struct config_generic * gconf, GucAction action);
2584 static void ReportGUCOption(struct config_generic * record);
2585 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2586 static void ShowAllGUCConfig(DestReceiver *dest);
2587 static char *_ShowOption(struct config_generic * record, bool use_units);
2588 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2589
2590
2591 /*
2592  * Some infrastructure for checking malloc/strdup/realloc calls
2593  */
2594 static void *
2595 guc_malloc(int elevel, size_t size)
2596 {
2597         void       *data;
2598
2599         data = malloc(size);
2600         if (data == NULL)
2601                 ereport(elevel,
2602                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2603                                  errmsg("out of memory")));
2604         return data;
2605 }
2606
2607 static void *
2608 guc_realloc(int elevel, void *old, size_t size)
2609 {
2610         void       *data;
2611
2612         data = realloc(old, size);
2613         if (data == NULL)
2614                 ereport(elevel,
2615                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2616                                  errmsg("out of memory")));
2617         return data;
2618 }
2619
2620 static char *
2621 guc_strdup(int elevel, const char *src)
2622 {
2623         char       *data;
2624
2625         data = strdup(src);
2626         if (data == NULL)
2627                 ereport(elevel,
2628                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2629                                  errmsg("out of memory")));
2630         return data;
2631 }
2632
2633
2634 /*
2635  * Support for assigning to a field of a string GUC item.  Free the prior
2636  * value if it's not referenced anywhere else in the item (including stacked
2637  * states).
2638  */
2639 static void
2640 set_string_field(struct config_string * conf, char **field, char *newval)
2641 {
2642         char       *oldval = *field;
2643         GucStack   *stack;
2644
2645         /* Do the assignment */
2646         *field = newval;
2647
2648         /* Exit if any duplicate references, or if old value was NULL anyway */
2649         if (oldval == NULL ||
2650                 oldval == *(conf->variable) ||
2651                 oldval == conf->reset_val ||
2652                 oldval == conf->boot_val)
2653                 return;
2654         for (stack = conf->gen.stack; stack; stack = stack->prev)
2655         {
2656                 if (oldval == stack->prior.stringval ||
2657                         oldval == stack->masked.stringval)
2658                         return;
2659         }
2660
2661         /* Not used anymore, so free it */
2662         free(oldval);
2663 }
2664
2665 /*
2666  * Detect whether strval is referenced anywhere in a GUC string item
2667  */
2668 static bool
2669 string_field_used(struct config_string * conf, char *strval)
2670 {
2671         GucStack   *stack;
2672
2673         if (strval == *(conf->variable) ||
2674                 strval == conf->reset_val ||
2675                 strval == conf->boot_val)
2676                 return true;
2677         for (stack = conf->gen.stack; stack; stack = stack->prev)
2678         {
2679                 if (strval == stack->prior.stringval ||
2680                         strval == stack->masked.stringval)
2681                         return true;
2682         }
2683         return false;
2684 }
2685
2686 /*
2687  * Support for copying a variable's active value into a stack entry
2688  */
2689 static void
2690 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2691 {
2692         switch (gconf->vartype)
2693         {
2694                 case PGC_BOOL:
2695                         val->boolval =
2696                                 *((struct config_bool *) gconf)->variable;
2697                         break;
2698                 case PGC_INT:
2699                         val->intval =
2700                                 *((struct config_int *) gconf)->variable;
2701                         break;
2702                 case PGC_REAL:
2703                         val->realval =
2704                                 *((struct config_real *) gconf)->variable;
2705                         break;
2706                 case PGC_STRING:
2707                         /* we assume stringval is NULL if not valid */
2708                         set_string_field((struct config_string *) gconf,
2709                                                          &(val->stringval),
2710                                                          *((struct config_string *) gconf)->variable);
2711                         break;
2712                 case PGC_ENUM:
2713                         val->enumval =
2714                                 *((struct config_enum *) gconf)->variable;
2715                         break;
2716         }
2717 }
2718
2719 /*
2720  * Support for discarding a no-longer-needed value in a stack entry
2721  */
2722 static void
2723 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2724 {
2725         switch (gconf->vartype)
2726         {
2727                 case PGC_BOOL:
2728                 case PGC_INT:
2729                 case PGC_REAL:
2730                 case PGC_ENUM:
2731                         /* no need to do anything */
2732                         break;
2733                 case PGC_STRING:
2734                         set_string_field((struct config_string *) gconf,
2735                                                          &(val->stringval),
2736                                                          NULL);
2737                         break;
2738         }
2739 }
2740
2741
2742 /*
2743  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2744  */
2745 struct config_generic **
2746 get_guc_variables(void)
2747 {
2748         return guc_variables;
2749 }
2750
2751
2752 /*
2753  * Build the sorted array.      This is split out so that it could be
2754  * re-executed after startup (eg, we could allow loadable modules to
2755  * add vars, and then we'd need to re-sort).
2756  */
2757 void
2758 build_guc_variables(void)
2759 {
2760         int                     size_vars;
2761         int                     num_vars = 0;
2762         struct config_generic **guc_vars;
2763         int                     i;
2764
2765         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2766         {
2767                 struct config_bool *conf = &ConfigureNamesBool[i];
2768
2769                 /* Rather than requiring vartype to be filled in by hand, do this: */
2770                 conf->gen.vartype = PGC_BOOL;
2771                 num_vars++;
2772         }
2773
2774         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2775         {
2776                 struct config_int *conf = &ConfigureNamesInt[i];
2777
2778                 conf->gen.vartype = PGC_INT;
2779                 num_vars++;
2780         }
2781
2782         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2783         {
2784                 struct config_real *conf = &ConfigureNamesReal[i];
2785
2786                 conf->gen.vartype = PGC_REAL;
2787                 num_vars++;
2788         }
2789
2790         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2791         {
2792                 struct config_string *conf = &ConfigureNamesString[i];
2793
2794                 conf->gen.vartype = PGC_STRING;
2795                 num_vars++;
2796         }
2797
2798         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2799         {
2800                 struct config_enum *conf = &ConfigureNamesEnum[i];
2801
2802                 conf->gen.vartype = PGC_ENUM;
2803                 num_vars++;
2804         }
2805
2806         /*
2807          * Create table with 20% slack
2808          */
2809         size_vars = num_vars + num_vars / 4;
2810
2811         guc_vars = (struct config_generic **)
2812                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2813
2814         num_vars = 0;
2815
2816         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2817                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2818
2819         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2820                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2821
2822         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2823                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2824
2825         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2826                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2827
2828         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2829                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2830
2831         if (guc_variables)
2832                 free(guc_variables);
2833         guc_variables = guc_vars;
2834         num_guc_variables = num_vars;
2835         size_guc_variables = size_vars;
2836         qsort((void *) guc_variables, num_guc_variables,
2837                   sizeof(struct config_generic *), guc_var_compare);
2838 }
2839
2840 /*
2841  * Add a new GUC variable to the list of known variables. The
2842  * list is expanded if needed.
2843  */
2844 static bool
2845 add_guc_variable(struct config_generic * var, int elevel)
2846 {
2847         if (num_guc_variables + 1 >= size_guc_variables)
2848         {
2849                 /*
2850                  * Increase the vector by 25%
2851                  */
2852                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
2853                 struct config_generic **guc_vars;
2854
2855                 if (size_vars == 0)
2856                 {
2857                         size_vars = 100;
2858                         guc_vars = (struct config_generic **)
2859                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
2860                 }
2861                 else
2862                 {
2863                         guc_vars = (struct config_generic **)
2864                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
2865                 }
2866
2867                 if (guc_vars == NULL)
2868                         return false;           /* out of memory */
2869
2870                 guc_variables = guc_vars;
2871                 size_guc_variables = size_vars;
2872         }
2873         guc_variables[num_guc_variables++] = var;
2874         qsort((void *) guc_variables, num_guc_variables,
2875                   sizeof(struct config_generic *), guc_var_compare);
2876         return true;
2877 }
2878
2879 /*
2880  * Create and add a placeholder variable. It's presumed to belong
2881  * to a valid custom variable class at this point.
2882  */
2883 static struct config_generic *
2884 add_placeholder_variable(const char *name, int elevel)
2885 {
2886         size_t          sz = sizeof(struct config_string) + sizeof(char *);
2887         struct config_string *var;
2888         struct config_generic *gen;
2889
2890         var = (struct config_string *) guc_malloc(elevel, sz);
2891         if (var == NULL)
2892                 return NULL;
2893         memset(var, 0, sz);
2894         gen = &var->gen;
2895
2896         gen->name = guc_strdup(elevel, name);
2897         if (gen->name == NULL)
2898         {
2899                 free(var);
2900                 return NULL;
2901         }
2902
2903         gen->context = PGC_USERSET;
2904         gen->group = CUSTOM_OPTIONS;
2905         gen->short_desc = "GUC placeholder variable";
2906         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
2907         gen->vartype = PGC_STRING;
2908
2909         /*
2910          * The char* is allocated at the end of the struct since we have no
2911          * 'static' place to point to.  Note that the current value, as well as
2912          * the boot and reset values, start out NULL.
2913          */
2914         var->variable = (char **) (var + 1);
2915
2916         if (!add_guc_variable((struct config_generic *) var, elevel))
2917         {
2918                 free((void *) gen->name);
2919                 free(var);
2920                 return NULL;
2921         }
2922
2923         return gen;
2924 }
2925
2926 /*
2927  * Detect whether the portion of "name" before dotPos matches any custom
2928  * variable class name listed in custom_var_classes.  The latter must be
2929  * formatted the way that assign_custom_variable_classes does it, ie,
2930  * no whitespace.  NULL is valid for custom_var_classes.
2931  */
2932 static bool
2933 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
2934 {
2935         bool            result = false;
2936         const char *ccs = custom_var_classes;
2937
2938         if (ccs != NULL)
2939         {
2940                 const char *start = ccs;
2941
2942                 for (;; ++ccs)
2943                 {
2944                         char            c = *ccs;
2945
2946                         if (c == '\0' || c == ',')
2947                         {
2948                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
2949                                 {
2950                                         result = true;
2951                                         break;
2952                                 }
2953                                 if (c == '\0')
2954                                         break;
2955                                 start = ccs + 1;
2956                         }
2957                 }
2958         }
2959         return result;
2960 }
2961
2962 /*
2963  * Look up option NAME.  If it exists, return a pointer to its record,
2964  * else return NULL.  If create_placeholders is TRUE, we'll create a
2965  * placeholder record for a valid-looking custom variable name.
2966  */
2967 static struct config_generic *
2968 find_option(const char *name, bool create_placeholders, int elevel)
2969 {
2970         const char **key = &name;
2971         struct config_generic **res;
2972         int                     i;
2973
2974         Assert(name);
2975
2976         /*
2977          * By equating const char ** with struct config_generic *, we are assuming
2978          * the name field is first in config_generic.
2979          */
2980         res = (struct config_generic **) bsearch((void *) &key,
2981                                                                                          (void *) guc_variables,
2982                                                                                          num_guc_variables,
2983                                                                                          sizeof(struct config_generic *),
2984                                                                                          guc_var_compare);
2985         if (res)
2986                 return *res;
2987
2988         /*
2989          * See if the name is an obsolete name for a variable.  We assume that the
2990          * set of supported old names is short enough that a brute-force search is
2991          * the best way.
2992          */
2993         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
2994         {
2995                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
2996                         return find_option(map_old_guc_names[i + 1], false, elevel);
2997         }
2998
2999         if (create_placeholders)
3000         {
3001                 /*
3002                  * Check if the name is qualified, and if so, check if the qualifier
3003                  * matches any custom variable class.  If so, add a placeholder.
3004                  */
3005                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3006
3007                 if (dot != NULL &&
3008                         is_custom_class(name, dot - name, custom_variable_classes))
3009                         return add_placeholder_variable(name, elevel);
3010         }
3011
3012         /* Unknown name */
3013         return NULL;
3014 }
3015
3016
3017 /*
3018  * comparator for qsorting and bsearching guc_variables array
3019  */
3020 static int
3021 guc_var_compare(const void *a, const void *b)
3022 {
3023         struct config_generic *confa = *(struct config_generic **) a;
3024         struct config_generic *confb = *(struct config_generic **) b;
3025
3026         return guc_name_compare(confa->name, confb->name);
3027 }
3028
3029 /*
3030  * the bare comparison function for GUC names
3031  */
3032 static int
3033 guc_name_compare(const char *namea, const char *nameb)
3034 {
3035         /*
3036          * The temptation to use strcasecmp() here must be resisted, because the
3037          * array ordering has to remain stable across setlocale() calls. So, build
3038          * our own with a simple ASCII-only downcasing.
3039          */
3040         while (*namea && *nameb)
3041         {
3042                 char            cha = *namea++;
3043                 char            chb = *nameb++;
3044
3045                 if (cha >= 'A' && cha <= 'Z')
3046                         cha += 'a' - 'A';
3047                 if (chb >= 'A' && chb <= 'Z')
3048                         chb += 'a' - 'A';
3049                 if (cha != chb)
3050                         return cha - chb;
3051         }
3052         if (*namea)
3053                 return 1;                               /* a is longer */
3054         if (*nameb)
3055                 return -1;                              /* b is longer */
3056         return 0;
3057 }
3058
3059
3060 /*
3061  * Initialize GUC options during program startup.
3062  *
3063  * Note that we cannot read the config file yet, since we have not yet
3064  * processed command-line switches.
3065  */
3066 void
3067 InitializeGUCOptions(void)
3068 {
3069         int                     i;
3070         char       *env;
3071         long            stack_rlimit;
3072
3073         /*
3074          * Before log_line_prefix could possibly receive a nonempty setting, make
3075          * sure that timezone processing is minimally alive (see elog.c).
3076          */
3077         pg_timezone_pre_initialize();
3078
3079         /*
3080          * Build sorted array of all GUC variables.
3081          */
3082         build_guc_variables();
3083
3084         /*
3085          * Load all variables with their compiled-in defaults, and initialize
3086          * status fields as needed.
3087          */
3088         for (i = 0; i < num_guc_variables; i++)
3089         {
3090                 struct config_generic *gconf = guc_variables[i];
3091
3092                 gconf->status = 0;
3093                 gconf->reset_source = PGC_S_DEFAULT;
3094                 gconf->source = PGC_S_DEFAULT;
3095                 gconf->stack = NULL;
3096
3097                 switch (gconf->vartype)
3098                 {
3099                         case PGC_BOOL:
3100                                 {
3101                                         struct config_bool *conf = (struct config_bool *) gconf;
3102
3103                                         if (conf->assign_hook)
3104                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3105                                                                                                    PGC_S_DEFAULT))
3106                                                         elog(FATAL, "failed to initialize %s to %d",
3107                                                                  conf->gen.name, (int) conf->boot_val);
3108                                         *conf->variable = conf->reset_val = conf->boot_val;
3109                                         break;
3110                                 }
3111                         case PGC_INT:
3112                                 {
3113                                         struct config_int *conf = (struct config_int *) gconf;
3114
3115                                         Assert(conf->boot_val >= conf->min);
3116                                         Assert(conf->boot_val <= conf->max);
3117                                         if (conf->assign_hook)
3118                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3119                                                                                                    PGC_S_DEFAULT))
3120                                                         elog(FATAL, "failed to initialize %s to %d",
3121                                                                  conf->gen.name, conf->boot_val);
3122                                         *conf->variable = conf->reset_val = conf->boot_val;
3123                                         break;
3124                                 }
3125                         case PGC_REAL:
3126                                 {
3127                                         struct config_real *conf = (struct config_real *) gconf;
3128
3129                                         Assert(conf->boot_val >= conf->min);
3130                                         Assert(conf->boot_val <= conf->max);
3131                                         if (conf->assign_hook)
3132                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3133                                                                                                    PGC_S_DEFAULT))
3134                                                         elog(FATAL, "failed to initialize %s to %g",
3135                                                                  conf->gen.name, conf->boot_val);
3136                                         *conf->variable = conf->reset_val = conf->boot_val;
3137                                         break;
3138                                 }
3139                         case PGC_STRING:
3140                                 {
3141                                         struct config_string *conf = (struct config_string *) gconf;
3142                                         char       *str;
3143
3144                                         *conf->variable = NULL;
3145                                         conf->reset_val = NULL;
3146
3147                                         if (conf->boot_val == NULL)
3148                                         {
3149                                                 /* leave the value NULL, do not call assign hook */
3150                                                 break;
3151                                         }
3152
3153                                         str = guc_strdup(FATAL, conf->boot_val);
3154                                         conf->reset_val = str;
3155
3156                                         if (conf->assign_hook)
3157                                         {
3158                                                 const char *newstr;
3159
3160                                                 newstr = (*conf->assign_hook) (str, true,
3161                                                                                                            PGC_S_DEFAULT);
3162                                                 if (newstr == NULL)
3163                                                 {
3164                                                         elog(FATAL, "failed to initialize %s to \"%s\"",
3165                                                                  conf->gen.name, str);
3166                                                 }
3167                                                 else if (newstr != str)
3168                                                 {
3169                                                         free(str);
3170
3171                                                         /*
3172                                                          * See notes in set_config_option about casting
3173                                                          */
3174                                                         str = (char *) newstr;
3175                                                         conf->reset_val = str;
3176                                                 }
3177                                         }
3178                                         *conf->variable = str;
3179                                         break;
3180                                 }
3181                         case PGC_ENUM:
3182                                 {
3183                                         struct config_enum *conf = (struct config_enum *) gconf;
3184
3185                                         if (conf->assign_hook)
3186                                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3187                                                                                                    PGC_S_DEFAULT))
3188                                                         elog(FATAL, "failed to initialize %s to %s",
3189                                                                  conf->gen.name,
3190                                                                  config_enum_lookup_by_value(conf, conf->boot_val));
3191                                         *conf->variable = conf->reset_val = conf->boot_val;
3192                                         break;
3193                                 }
3194                 }
3195         }
3196
3197         guc_dirty = false;
3198
3199         reporting_enabled = false;
3200
3201         /*
3202          * Prevent any attempt to override the transaction modes from
3203          * non-interactive sources.
3204          */
3205         SetConfigOption("transaction_isolation", "default",
3206                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3207         SetConfigOption("transaction_read_only", "no",
3208                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3209
3210         /*
3211          * For historical reasons, some GUC parameters can receive defaults from
3212          * environment variables.  Process those settings.      NB: if you add or
3213          * remove anything here, see also ProcessConfigFile().
3214          */
3215
3216         env = getenv("PGPORT");
3217         if (env != NULL)
3218                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3219
3220         env = getenv("PGDATESTYLE");
3221         if (env != NULL)
3222                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3223
3224         env = getenv("PGCLIENTENCODING");
3225         if (env != NULL)
3226                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3227
3228         /*
3229          * rlimit isn't exactly an "environment variable", but it behaves about
3230          * the same.  If we can identify the platform stack depth rlimit, increase
3231          * default stack depth setting up to whatever is safe (but at most 2MB).
3232          */
3233         stack_rlimit = get_stack_depth_rlimit();
3234         if (stack_rlimit > 0)
3235         {
3236                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3237
3238                 if (new_limit > 100)
3239                 {
3240                         char            limbuf[16];
3241
3242                         new_limit = Min(new_limit, 2048);
3243                         sprintf(limbuf, "%d", new_limit);
3244                         SetConfigOption("max_stack_depth", limbuf,
3245                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3246                 }
3247         }
3248 }
3249
3250
3251 /*
3252  * Select the configuration files and data directory to be used, and
3253  * do the initial read of postgresql.conf.
3254  *
3255  * This is called after processing command-line switches.
3256  *              userDoption is the -D switch value if any (NULL if unspecified).
3257  *              progname is just for use in error messages.
3258  *
3259  * Returns true on success; on failure, prints a suitable error message
3260  * to stderr and returns false.
3261  */
3262 bool
3263 SelectConfigFiles(const char *userDoption, const char *progname)
3264 {
3265         char       *configdir;
3266         char       *fname;
3267         struct stat stat_buf;
3268
3269         /* configdir is -D option, or $PGDATA if no -D */
3270         if (userDoption)
3271                 configdir = make_absolute_path(userDoption);
3272         else
3273                 configdir = make_absolute_path(getenv("PGDATA"));
3274
3275         /*
3276          * Find the configuration file: if config_file was specified on the
3277          * command line, use it, else use configdir/postgresql.conf.  In any case
3278          * ensure the result is an absolute path, so that it will be interpreted
3279          * the same way by future backends.
3280          */
3281         if (ConfigFileName)
3282                 fname = make_absolute_path(ConfigFileName);
3283         else if (configdir)
3284         {
3285                 fname = guc_malloc(FATAL,
3286                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3287                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3288         }
3289         else
3290         {
3291                 write_stderr("%s does not know where to find the server configuration file.\n"
3292                                          "You must specify the --config-file or -D invocation "
3293                                          "option or set the PGDATA environment variable.\n",
3294                                          progname);
3295                 return false;
3296         }
3297
3298         /*
3299          * Set the ConfigFileName GUC variable to its final value, ensuring that
3300          * it can't be overridden later.
3301          */
3302         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3303         free(fname);
3304
3305         /*
3306          * Now read the config file for the first time.
3307          */
3308         if (stat(ConfigFileName, &stat_buf) != 0)
3309         {
3310                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3311                                          progname, ConfigFileName, strerror(errno));
3312                 return false;
3313         }
3314
3315         ProcessConfigFile(PGC_POSTMASTER);
3316
3317         /*
3318          * If the data_directory GUC variable has been set, use that as DataDir;
3319          * otherwise use configdir if set; else punt.
3320          *
3321          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3322          * have to.
3323          */
3324         if (data_directory)
3325                 SetDataDir(data_directory);
3326         else if (configdir)
3327                 SetDataDir(configdir);
3328         else
3329         {
3330                 write_stderr("%s does not know where to find the database system data.\n"
3331                                          "This can be specified as \"data_directory\" in \"%s\", "
3332                                          "or by the -D invocation option, or by the "
3333                                          "PGDATA environment variable.\n",
3334                                          progname, ConfigFileName);
3335                 return false;
3336         }
3337
3338         /*
3339          * Reflect the final DataDir value back into the data_directory GUC var.
3340          * (If you are wondering why we don't just make them a single variable,
3341          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3342          * child backends specially.  XXX is that still true?  Given that we now
3343          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3344          * DataDir in advance.)
3345          */
3346         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3347
3348         /*
3349          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3350          */
3351         if (HbaFileName)
3352                 fname = make_absolute_path(HbaFileName);
3353         else if (configdir)
3354         {
3355                 fname = guc_malloc(FATAL,
3356                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3357                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3358         }
3359         else
3360         {
3361                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3362                                          "This can be specified as \"hba_file\" in \"%s\", "
3363                                          "or by the -D invocation option, or by the "
3364                                          "PGDATA environment variable.\n",
3365                                          progname, ConfigFileName);
3366                 return false;
3367         }
3368         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3369         free(fname);
3370
3371         /*
3372          * Likewise for pg_ident.conf.
3373          */
3374         if (IdentFileName)
3375                 fname = make_absolute_path(IdentFileName);
3376         else if (configdir)
3377         {
3378                 fname = guc_malloc(FATAL,
3379                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3380                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3381         }
3382         else
3383         {
3384                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3385                                          "This can be specified as \"ident_file\" in \"%s\", "
3386                                          "or by the -D invocation option, or by the "
3387                                          "PGDATA environment variable.\n",
3388                                          progname, ConfigFileName);
3389                 return false;
3390         }
3391         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3392         free(fname);
3393
3394         free(configdir);
3395
3396         return true;
3397 }
3398
3399
3400 /*
3401  * Reset all options to their saved default values (implements RESET ALL)
3402  */
3403 void
3404 ResetAllOptions(void)
3405 {
3406         int                     i;
3407
3408         for (i = 0; i < num_guc_variables; i++)
3409         {
3410                 struct config_generic *gconf = guc_variables[i];
3411
3412                 /* Don't reset non-SET-able values */
3413                 if (gconf->context != PGC_SUSET &&
3414                         gconf->context != PGC_USERSET)
3415                         continue;
3416                 /* Don't reset if special exclusion from RESET ALL */
3417                 if (gconf->flags & GUC_NO_RESET_ALL)
3418                         continue;
3419                 /* No need to reset if wasn't SET */
3420                 if (gconf->source <= PGC_S_OVERRIDE)
3421                         continue;
3422
3423                 /* Save old value to support transaction abort */
3424                 push_old_value(gconf, GUC_ACTION_SET);
3425
3426                 switch (gconf->vartype)
3427                 {
3428                         case PGC_BOOL:
3429                                 {
3430                                         struct config_bool *conf = (struct config_bool *) gconf;
3431
3432                                         if (conf->assign_hook)
3433                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3434                                                                                                    PGC_S_SESSION))
3435                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3436                                         *conf->variable = conf->reset_val;
3437                                         conf->gen.source = conf->gen.reset_source;
3438                                         break;
3439                                 }
3440                         case PGC_INT:
3441                                 {
3442                                         struct config_int *conf = (struct config_int *) gconf;
3443
3444                                         if (conf->assign_hook)
3445                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3446                                                                                                    PGC_S_SESSION))
3447                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3448                                         *conf->variable = conf->reset_val;
3449                                         conf->gen.source = conf->gen.reset_source;
3450                                         break;
3451                                 }
3452                         case PGC_REAL:
3453                                 {
3454                                         struct config_real *conf = (struct config_real *) gconf;
3455
3456                                         if (conf->assign_hook)
3457                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3458                                                                                                    PGC_S_SESSION))
3459                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3460                                         *conf->variable = conf->reset_val;
3461                                         conf->gen.source = conf->gen.reset_source;
3462                                         break;
3463                                 }
3464                         case PGC_STRING:
3465                                 {
3466                                         struct config_string *conf = (struct config_string *) gconf;
3467                                         char       *str;
3468
3469                                         /* We need not strdup here */
3470                                         str = conf->reset_val;
3471
3472                                         if (conf->assign_hook && str)
3473                                         {
3474                                                 const char *newstr;
3475
3476                                                 newstr = (*conf->assign_hook) (str, true,
3477                                                                                                            PGC_S_SESSION);
3478                                                 if (newstr == NULL)
3479                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3480                                                 else if (newstr != str)
3481                                                 {
3482                                                         /*
3483                                                          * See notes in set_config_option about casting
3484                                                          */
3485                                                         str = (char *) newstr;
3486                                                 }
3487                                         }
3488
3489                                         set_string_field(conf, conf->variable, str);
3490                                         conf->gen.source = conf->gen.reset_source;
3491                                         break;
3492                                 }
3493                         case PGC_ENUM:
3494                                 {
3495                                         struct config_enum *conf = (struct config_enum *) gconf;
3496
3497                                         if (conf->assign_hook)
3498                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3499                                                                                                    PGC_S_SESSION))
3500                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3501                                         *conf->variable = conf->reset_val;
3502                                         conf->gen.source = conf->gen.reset_source;
3503                                         break;
3504                                 }
3505                 }
3506
3507                 if (gconf->flags & GUC_REPORT)
3508                         ReportGUCOption(gconf);
3509         }
3510 }
3511
3512
3513 /*
3514  * push_old_value
3515  *              Push previous state during transactional assignment to a GUC variable.
3516  */
3517 static void
3518 push_old_value(struct config_generic * gconf, GucAction action)
3519 {
3520         GucStack   *stack;
3521
3522         /* If we're not inside a nest level, do nothing */
3523         if (GUCNestLevel == 0)
3524                 return;
3525
3526         /* Do we already have a stack entry of the current nest level? */
3527         stack = gconf->stack;
3528         if (stack && stack->nest_level >= GUCNestLevel)
3529         {
3530                 /* Yes, so adjust its state if necessary */
3531                 Assert(stack->nest_level == GUCNestLevel);
3532                 switch (action)
3533                 {
3534                         case GUC_ACTION_SET:
3535                                 /* SET overrides any prior action at same nest level */
3536                                 if (stack->state == GUC_SET_LOCAL)
3537                                 {
3538                                         /* must discard old masked value */
3539                                         discard_stack_value(gconf, &stack->masked);
3540                                 }
3541                                 stack->state = GUC_SET;
3542                                 break;
3543                         case GUC_ACTION_LOCAL:
3544                                 if (stack->state == GUC_SET)
3545                                 {
3546                                         /* SET followed by SET LOCAL, remember SET's value */
3547                                         set_stack_value(gconf, &stack->masked);
3548                                         stack->state = GUC_SET_LOCAL;
3549                                 }
3550                                 /* in all other cases, no change to stack entry */
3551                                 break;
3552                         case GUC_ACTION_SAVE:
3553                                 /* Could only have a prior SAVE of same variable */
3554                                 Assert(stack->state == GUC_SAVE);
3555                                 break;
3556                 }
3557                 Assert(guc_dirty);              /* must be set already */
3558                 return;
3559         }
3560
3561         /*
3562          * Push a new stack entry
3563          *
3564          * We keep all the stack entries in TopTransactionContext for simplicity.
3565          */
3566         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3567                                                                                                 sizeof(GucStack));
3568
3569         stack->prev = gconf->stack;
3570         stack->nest_level = GUCNestLevel;
3571         switch (action)
3572         {
3573                 case GUC_ACTION_SET:
3574                         stack->state = GUC_SET;
3575                         break;
3576                 case GUC_ACTION_LOCAL:
3577                         stack->state = GUC_LOCAL;
3578                         break;
3579                 case GUC_ACTION_SAVE:
3580                         stack->state = GUC_SAVE;
3581                         break;
3582         }
3583         stack->source = gconf->source;
3584         set_stack_value(gconf, &stack->prior);
3585
3586         gconf->stack = stack;
3587
3588         /* Ensure we remember to pop at end of xact */
3589         guc_dirty = true;
3590 }
3591
3592
3593 /*
3594  * Do GUC processing at main transaction start.
3595  */
3596 void
3597 AtStart_GUC(void)
3598 {
3599         /*
3600          * The nest level should be 0 between transactions; if it isn't, somebody
3601          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3602          * throw a warning but make no other effort to clean up.
3603          */
3604         if (GUCNestLevel != 0)
3605                 elog(WARNING, "GUC nest level = %d at transaction start",
3606                          GUCNestLevel);
3607         GUCNestLevel = 1;
3608 }
3609
3610 /*
3611  * Enter a new nesting level for GUC values.  This is called at subtransaction
3612  * start and when entering a function that has proconfig settings.      NOTE that
3613  * we must not risk error here, else subtransaction start will be unhappy.
3614  */
3615 int
3616 NewGUCNestLevel(void)
3617 {
3618         return ++GUCNestLevel;
3619 }
3620
3621 /*
3622  * Do GUC processing at transaction or subtransaction commit or abort, or
3623  * when exiting a function that has proconfig settings.  (The name is thus
3624  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3625  * During abort, we discard all GUC settings that were applied at nesting
3626  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3627  */
3628 void
3629 AtEOXact_GUC(bool isCommit, int nestLevel)
3630 {
3631         bool            still_dirty;
3632         int                     i;
3633
3634         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3635
3636         /* Quick exit if nothing's changed in this transaction */
3637         if (!guc_dirty)
3638         {
3639                 GUCNestLevel = nestLevel - 1;
3640                 return;
3641         }
3642
3643         still_dirty = false;
3644         for (i = 0; i < num_guc_variables; i++)
3645         {
3646                 struct config_generic *gconf = guc_variables[i];
3647                 GucStack   *stack;
3648
3649                 /*
3650                  * Process and pop each stack entry within the nest level.      To
3651                  * simplify fmgr_security_definer(), we allow failure exit from a
3652                  * function-with-SET-options to be recovered at the surrounding
3653                  * transaction or subtransaction abort; so there could be more than
3654                  * one stack entry to pop.
3655                  */
3656                 while ((stack = gconf->stack) != NULL &&
3657                            stack->nest_level >= nestLevel)
3658                 {
3659                         GucStack   *prev = stack->prev;
3660                         bool            restorePrior = false;
3661                         bool            restoreMasked = false;
3662                         bool            changed;
3663
3664                         /*
3665                          * In this next bit, if we don't set either restorePrior or
3666                          * restoreMasked, we must "discard" any unwanted fields of the
3667                          * stack entries to avoid leaking memory.  If we do set one of
3668                          * those flags, unused fields will be cleaned up after restoring.
3669                          */
3670                         if (!isCommit)          /* if abort, always restore prior value */
3671                                 restorePrior = true;
3672                         else if (stack->state == GUC_SAVE)
3673                                 restorePrior = true;
3674                         else if (stack->nest_level == 1)
3675                         {
3676                                 /* transaction commit */
3677                                 if (stack->state == GUC_SET_LOCAL)
3678                                         restoreMasked = true;
3679                                 else if (stack->state == GUC_SET)
3680                                 {
3681                                         /* we keep the current active value */
3682                                         discard_stack_value(gconf, &stack->prior);
3683                                 }
3684                                 else    /* must be GUC_LOCAL */
3685                                         restorePrior = true;
3686                         }
3687                         else if (prev == NULL ||
3688                                          prev->nest_level < stack->nest_level - 1)
3689                         {
3690                                 /* decrement entry's level and do not pop it */
3691                                 stack->nest_level--;
3692                                 continue;
3693                         }
3694                         else
3695                         {
3696                                 /*
3697                                  * We have to merge this stack entry into prev. See README for
3698                                  * discussion of this bit.
3699                                  */
3700                                 switch (stack->state)
3701                                 {
3702                                         case GUC_SAVE:
3703                                                 Assert(false);  /* can't get here */
3704
3705                                         case GUC_SET:
3706                                                 /* next level always becomes SET */
3707                                                 discard_stack_value(gconf, &stack->prior);
3708                                                 if (prev->state == GUC_SET_LOCAL)
3709                                                         discard_stack_value(gconf, &prev->masked);
3710                                                 prev->state = GUC_SET;
3711                                                 break;
3712
3713                                         case GUC_LOCAL:
3714                                                 if (prev->state == GUC_SET)
3715                                                 {
3716                                                         /* LOCAL migrates down */
3717                                                         prev->masked = stack->prior;
3718                                                         prev->state = GUC_SET_LOCAL;
3719                                                 }
3720                                                 else
3721                                                 {
3722                                                         /* else just forget this stack level */
3723                                                         discard_stack_value(gconf, &stack->prior);
3724                                                 }
3725                                                 break;
3726
3727                                         case GUC_SET_LOCAL:
3728                                                 /* prior state at this level no longer wanted */
3729                                                 discard_stack_value(gconf, &stack->prior);
3730                                                 /* copy down the masked state */
3731                                                 if (prev->state == GUC_SET_LOCAL)
3732                                                         discard_stack_value(gconf, &prev->masked);
3733                                                 prev->masked = stack->masked;
3734                                                 prev->state = GUC_SET_LOCAL;
3735                                                 break;
3736                                 }
3737                         }
3738
3739                         changed = false;
3740
3741                         if (restorePrior || restoreMasked)
3742                         {
3743                                 /* Perform appropriate restoration of the stacked value */
3744                                 union config_var_value newvalue;
3745                                 GucSource       newsource;
3746
3747                                 if (restoreMasked)
3748                                 {
3749                                         newvalue = stack->masked;
3750                                         newsource = PGC_S_SESSION;
3751                                 }
3752                                 else
3753                                 {
3754                                         newvalue = stack->prior;
3755                                         newsource = stack->source;
3756                                 }
3757
3758                                 switch (gconf->vartype)
3759                                 {
3760                                         case PGC_BOOL:
3761                                                 {
3762                                                         struct config_bool *conf = (struct config_bool *) gconf;
3763                                                         bool            newval = newvalue.boolval;
3764
3765                                                         if (*conf->variable != newval)
3766                                                         {
3767                                                                 if (conf->assign_hook)
3768                                                                         if (!(*conf->assign_hook) (newval,
3769                                                                                                            true, PGC_S_OVERRIDE))
3770                                                                                 elog(LOG, "failed to commit %s",
3771                                                                                          conf->gen.name);
3772                                                                 *conf->variable = newval;
3773                                                                 changed = true;
3774                                                         }
3775                                                         break;
3776                                                 }
3777                                         case PGC_INT:
3778                                                 {
3779                                                         struct config_int *conf = (struct config_int *) gconf;
3780                                                         int                     newval = newvalue.intval;
3781
3782                                                         if (*conf->variable != newval)
3783                                                         {
3784                                                                 if (conf->assign_hook)
3785                                                                         if (!(*conf->assign_hook) (newval,
3786                                                                                                            true, PGC_S_OVERRIDE))
3787                                                                                 elog(LOG, "failed to commit %s",
3788                                                                                          conf->gen.name);
3789                                                                 *conf->variable = newval;
3790                                                                 changed = true;
3791                                                         }
3792                                                         break;
3793                                                 }
3794                                         case PGC_REAL:
3795                                                 {
3796                                                         struct config_real *conf = (struct config_real *) gconf;
3797                                                         double          newval = newvalue.realval;
3798
3799                                                         if (*conf->variable != newval)
3800                                                         {
3801                                                                 if (conf->assign_hook)
3802                                                                         if (!(*conf->assign_hook) (newval,
3803                                                                                                            true, PGC_S_OVERRIDE))
3804                                                                                 elog(LOG, "failed to commit %s",
3805                                                                                          conf->gen.name);
3806                                                                 *conf->variable = newval;
3807                                                                 changed = true;
3808                                                         }
3809                                                         break;
3810                                                 }
3811                                         case PGC_STRING:
3812                                                 {
3813                                                         struct config_string *conf = (struct config_string *) gconf;
3814                                                         char       *newval = newvalue.stringval;
3815
3816                                                         if (*conf->variable != newval)
3817                                                         {
3818                                                                 if (conf->assign_hook && newval)
3819                                                                 {
3820                                                                         const char *newstr;
3821
3822                                                                         newstr = (*conf->assign_hook) (newval, true,
3823                                                                                                                          PGC_S_OVERRIDE);
3824                                                                         if (newstr == NULL)
3825                                                                                 elog(LOG, "failed to commit %s",
3826                                                                                          conf->gen.name);
3827                                                                         else if (newstr != newval)
3828                                                                         {
3829                                                                                 /*
3830                                                                                  * If newval should now be freed,
3831                                                                                  * it'll be taken care of below.
3832                                                                                  *
3833                                                                                  * See notes in set_config_option
3834                                                                                  * about casting
3835                                                                                  */
3836                                                                                 newval = (char *) newstr;
3837                                                                         }
3838                                                                 }
3839
3840                                                                 set_string_field(conf, conf->variable, newval);
3841                                                                 changed = true;
3842                                                         }
3843
3844                                                         /*
3845                                                          * Release stacked values if not used anymore. We
3846                                                          * could use discard_stack_value() here, but since
3847                                                          * we have type-specific code anyway, might as
3848                                                          * well inline it.
3849                                                          */
3850                                                         set_string_field(conf, &stack->prior.stringval, NULL);
3851                                                         set_string_field(conf, &stack->masked.stringval, NULL);
3852                                                         break;
3853                                                 }
3854                                         case PGC_ENUM:
3855                                                 {
3856                                                         struct config_enum *conf = (struct config_enum *) gconf;
3857                                                         int newval = newvalue.enumval;
3858
3859                                                         if (*conf->variable != newval)
3860                                                         {
3861                                                                 if (conf->assign_hook)
3862                                                                         if (!(*conf->assign_hook) (newval,
3863                                                                                                                            true, PGC_S_OVERRIDE))
3864                                                                                 elog(LOG, "failed to commit %s",
3865                                                                                          conf->gen.name);
3866                                                                 *conf->variable = newval;
3867                                                                 changed = true;
3868                                                         }
3869                                                         break;
3870                                                 }
3871                                 }
3872
3873                                 gconf->source = newsource;
3874                         }
3875
3876                         /* Finish popping the state stack */
3877                         gconf->stack = prev;
3878                         pfree(stack);
3879
3880                         /* Report new value if we changed it */
3881                         if (changed && (gconf->flags & GUC_REPORT))
3882                                 ReportGUCOption(gconf);
3883                 }                                               /* end of stack-popping loop */
3884
3885                 if (stack != NULL)
3886                         still_dirty = true;
3887         }
3888
3889         /* If there are no remaining stack entries, we can reset guc_dirty */
3890         guc_dirty = still_dirty;
3891
3892         /* Update nesting level */
3893         GUCNestLevel = nestLevel - 1;
3894 }
3895
3896
3897 /*
3898  * Start up automatic reporting of changes to variables marked GUC_REPORT.
3899  * This is executed at completion of backend startup.
3900  */
3901 void
3902 BeginReportingGUCOptions(void)
3903 {
3904         int                     i;
3905
3906         /*
3907          * Don't do anything unless talking to an interactive frontend of protocol
3908          * 3.0 or later.
3909          */
3910         if (whereToSendOutput != DestRemote ||
3911                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
3912                 return;
3913
3914         reporting_enabled = true;
3915
3916         /* Transmit initial values of interesting variables */
3917         for (i = 0; i < num_guc_variables; i++)
3918         {
3919                 struct config_generic *conf = guc_variables[i];
3920
3921                 if (conf->flags & GUC_REPORT)
3922                         ReportGUCOption(conf);
3923         }
3924 }
3925
3926 /*
3927  * ReportGUCOption: if appropriate, transmit option value to frontend
3928  */
3929 static void
3930 ReportGUCOption(struct config_generic * record)
3931 {
3932         if (reporting_enabled && (record->flags & GUC_REPORT))
3933         {
3934                 char       *val = _ShowOption(record, false);
3935                 StringInfoData msgbuf;
3936
3937                 pq_beginmessage(&msgbuf, 'S');
3938                 pq_sendstring(&msgbuf, record->name);
3939                 pq_sendstring(&msgbuf, val);
3940                 pq_endmessage(&msgbuf);
3941
3942                 pfree(val);
3943         }
3944 }
3945
3946
3947 /*
3948  * Try to interpret value as boolean value.  Valid values are: true,
3949  * false, yes, no, on, off, 1, 0; as well as unique prefixes thereof.
3950  * If the string parses okay, return true, else false.
3951  * If okay and result is not NULL, return the value in *result.
3952  */
3953 static bool
3954 parse_bool(const char *value, bool *result)
3955 {
3956         size_t          len = strlen(value);
3957
3958         if (pg_strncasecmp(value, "true", len) == 0)
3959         {
3960                 if (result)
3961                         *result = true;
3962         }
3963         else if (pg_strncasecmp(value, "false", len) == 0)
3964         {
3965                 if (result)
3966                         *result = false;
3967         }
3968
3969         else if (pg_strncasecmp(value, "yes", len) == 0)
3970         {
3971                 if (result)
3972                         *result = true;
3973         }
3974         else if (pg_strncasecmp(value, "no", len) == 0)
3975         {
3976                 if (result)
3977                         *result = false;
3978         }
3979
3980         /* 'o' is not unique enough */
3981         else if (pg_strncasecmp(value, "on", (len > 2 ? len : 2)) == 0)
3982         {
3983                 if (result)
3984                         *result = true;
3985         }
3986         else if (pg_strncasecmp(value, "off", (len > 2 ? len : 2)) == 0)
3987         {
3988                 if (result)
3989                         *result = false;
3990         }
3991
3992         else if (pg_strcasecmp(value, "1") == 0)
3993         {
3994                 if (result)
3995                         *result = true;
3996         }
3997         else if (pg_strcasecmp(value, "0") == 0)
3998         {
3999                 if (result)
4000                         *result = false;
4001         }
4002
4003         else
4004         {
4005                 if (result)
4006                         *result = false;        /* suppress compiler warning */
4007                 return false;
4008         }
4009         return true;
4010 }
4011
4012
4013
4014 /*
4015  * Try to parse value as an integer.  The accepted formats are the
4016  * usual decimal, octal, or hexadecimal formats, optionally followed by
4017  * a unit name if "flags" indicates a unit is allowed.
4018  *
4019  * If the string parses okay, return true, else false.
4020  * If okay and result is not NULL, return the value in *result.
4021  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4022  *      HINT message, or NULL if no hint provided.
4023  */
4024 static bool
4025 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4026 {
4027         int64           val;
4028         char       *endptr;
4029
4030         /* To suppress compiler warnings, always set output params */
4031         if (result)
4032                 *result = 0;
4033         if (hintmsg)
4034                 *hintmsg = NULL;
4035
4036         /* We assume here that int64 is at least as wide as long */
4037         errno = 0;
4038         val = strtol(value, &endptr, 0);
4039
4040         if (endptr == value)
4041                 return false;                   /* no HINT for integer syntax error */
4042
4043         if (errno == ERANGE || val != (int64) ((int32) val))
4044         {
4045                 if (hintmsg)
4046                         *hintmsg = gettext_noop("Value exceeds integer range.");
4047                 return false;
4048         }
4049
4050         /* allow whitespace between integer and unit */
4051         while (isspace((unsigned char) *endptr))
4052                 endptr++;
4053
4054         /* Handle possible unit */
4055         if (*endptr != '\0')
4056         {
4057                 /*
4058                  * Note: the multiple-switch coding technique here is a bit tedious,
4059                  * but seems necessary to avoid intermediate-value overflows.
4060                  *
4061                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4062                  * overflow due to units conversion, but there are few enough such
4063                  * machines that it does not seem worth trying to be smarter.
4064                  */
4065                 if (flags & GUC_UNIT_MEMORY)
4066                 {
4067                         /* Set hint for use if no match or trailing garbage */
4068                         if (hintmsg)
4069                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4070
4071 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4072 #error BLCKSZ must be between 1KB and 1MB
4073 #endif
4074 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4075 #error XLOG_BLCKSZ must be between 1KB and 1MB
4076 #endif
4077
4078                         if (strncmp(endptr, "kB", 2) == 0)
4079                         {
4080                                 endptr += 2;
4081                                 switch (flags & GUC_UNIT_MEMORY)
4082                                 {
4083                                         case GUC_UNIT_BLOCKS:
4084                                                 val /= (BLCKSZ / 1024);
4085                                                 break;
4086                                         case GUC_UNIT_XBLOCKS:
4087                                                 val /= (XLOG_BLCKSZ / 1024);
4088                                                 break;
4089                                 }
4090                         }
4091                         else if (strncmp(endptr, "MB", 2) == 0)
4092                         {
4093                                 endptr += 2;
4094                                 switch (flags & GUC_UNIT_MEMORY)
4095                                 {
4096                                         case GUC_UNIT_KB:
4097                                                 val *= KB_PER_MB;
4098                                                 break;
4099                                         case GUC_UNIT_BLOCKS:
4100                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4101                                                 break;
4102                                         case GUC_UNIT_XBLOCKS:
4103                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4104                                                 break;
4105                                 }
4106                         }
4107                         else if (strncmp(endptr, "GB", 2) == 0)
4108                         {
4109                                 endptr += 2;
4110                                 switch (flags & GUC_UNIT_MEMORY)
4111                                 {
4112                                         case GUC_UNIT_KB:
4113                                                 val *= KB_PER_GB;
4114                                                 break;
4115                                         case GUC_UNIT_BLOCKS:
4116                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4117                                                 break;
4118                                         case GUC_UNIT_XBLOCKS:
4119                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4120                                                 break;
4121                                 }
4122                         }
4123                 }
4124                 else if (flags & GUC_UNIT_TIME)
4125                 {
4126                         /* Set hint for use if no match or trailing garbage */
4127                         if (hintmsg)
4128                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4129
4130                         if (strncmp(endptr, "ms", 2) == 0)
4131                         {
4132                                 endptr += 2;
4133                                 switch (flags & GUC_UNIT_TIME)
4134                                 {
4135                                         case GUC_UNIT_S:
4136                                                 val /= MS_PER_S;
4137                                                 break;
4138                                         case GUC_UNIT_MIN:
4139                                                 val /= MS_PER_MIN;
4140                                                 break;
4141                                 }
4142                         }
4143                         else if (strncmp(endptr, "s", 1) == 0)
4144                         {
4145                                 endptr += 1;
4146                                 switch (flags & GUC_UNIT_TIME)
4147                                 {
4148                                         case GUC_UNIT_MS:
4149                                                 val *= MS_PER_S;
4150                                                 break;
4151                                         case GUC_UNIT_MIN:
4152                                                 val /= S_PER_MIN;
4153                                                 break;
4154                                 }
4155                         }
4156                         else if (strncmp(endptr, "min", 3) == 0)
4157                         {
4158                                 endptr += 3;
4159                                 switch (flags & GUC_UNIT_TIME)
4160                                 {
4161                                         case GUC_UNIT_MS:
4162                                                 val *= MS_PER_MIN;
4163                                                 break;
4164                                         case GUC_UNIT_S:
4165                                                 val *= S_PER_MIN;
4166                                                 break;
4167                                 }
4168                         }
4169                         else if (strncmp(endptr, "h", 1) == 0)
4170                         {
4171                                 endptr += 1;
4172                                 switch (flags & GUC_UNIT_TIME)
4173                                 {
4174                                         case GUC_UNIT_MS:
4175                                                 val *= MS_PER_H;
4176                                                 break;
4177                                         case GUC_UNIT_S:
4178                                                 val *= S_PER_H;
4179                                                 break;
4180                                         case GUC_UNIT_MIN:
4181                                                 val *= MIN_PER_H;
4182                                                 break;
4183                                 }
4184                         }
4185                         else if (strncmp(endptr, "d", 1) == 0)
4186                         {
4187                                 endptr += 1;
4188                                 switch (flags & GUC_UNIT_TIME)
4189                                 {
4190                                         case GUC_UNIT_MS:
4191                                                 val *= MS_PER_D;
4192                                                 break;
4193                                         case GUC_UNIT_S:
4194                                                 val *= S_PER_D;
4195                                                 break;
4196                                         case GUC_UNIT_MIN:
4197                                                 val *= MIN_PER_D;
4198                                                 break;
4199                                 }
4200                         }
4201                 }
4202
4203                 /* allow whitespace after unit */
4204                 while (isspace((unsigned char) *endptr))
4205                         endptr++;
4206
4207                 if (*endptr != '\0')
4208                         return false;           /* appropriate hint, if any, already set */
4209
4210                 /* Check for overflow due to units conversion */
4211                 if (val != (int64) ((int32) val))
4212                 {
4213                         if (hintmsg)
4214                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4215                         return false;
4216                 }
4217         }
4218
4219         if (result)
4220                 *result = (int) val;
4221         return true;
4222 }
4223
4224
4225
4226 /*
4227  * Try to parse value as a floating point number in the usual format.
4228  * If the string parses okay, return true, else false.
4229  * If okay and result is not NULL, return the value in *result.
4230  */
4231 static bool
4232 parse_real(const char *value, double *result)
4233 {
4234         double          val;
4235         char       *endptr;
4236
4237         if (result)
4238                 *result = 0;                    /* suppress compiler warning */
4239
4240         errno = 0;
4241         val = strtod(value, &endptr);
4242         if (endptr == value || errno == ERANGE)
4243                 return false;
4244
4245         /* allow whitespace after number */
4246         while (isspace((unsigned char) *endptr))
4247                 endptr++;
4248         if (*endptr != '\0')
4249                 return false;
4250
4251         if (result)
4252                 *result = val;
4253         return true;
4254 }
4255
4256
4257 /*
4258  * Lookup the name for an enum option with the selected value.
4259  * Should only ever be called with known-valid values, so throws
4260  * an elog(ERROR) if the enum option is not found.
4261  *
4262  * The returned string is a pointer to static data and not
4263  * allocated for modification.
4264  */
4265 const char *
4266 config_enum_lookup_by_value(struct config_enum *record, int val)
4267 {
4268         const struct config_enum_entry *entry = record->options;
4269         while (entry && entry->name)
4270         {
4271                 if (entry->val == val)
4272                         return entry->name;
4273                 entry++;
4274         }
4275         elog(ERROR, "could not find enum option %d for %s",
4276                  val, record->gen.name);
4277         return NULL; /* silence compiler */
4278 }
4279
4280
4281 /*
4282  * Lookup the value for an enum option with the selected name
4283  * (case-insensitive).
4284  * If the enum option is found, sets the retval value and returns
4285  * true. If it's not found, return FALSE and retval is set to 0.
4286  *
4287  */
4288 bool
4289 config_enum_lookup_by_name(struct config_enum *record, const char *value, int *retval)
4290 {
4291         const struct config_enum_entry *entry = record->options;
4292
4293         if (retval)
4294                 *retval = 0;                    /* suppress compiler warning */
4295
4296         while (entry && entry->name)
4297         {
4298                 if (pg_strcasecmp(value, entry->name) == 0)
4299                 {
4300                         *retval = entry->val;
4301                         return TRUE;
4302                 }
4303                 entry++;
4304         }
4305         return FALSE;
4306 }
4307
4308
4309 /*
4310  * Return a list of all available options for an enum, separated
4311  * by ", " (comma-space).
4312  * If prefix is non-NULL, it is added before the first enum value.
4313  * If suffix is non-NULL, it is added to the end of the string.
4314  */
4315 static char *
4316 config_enum_get_options(struct config_enum *record, const char *prefix, const char *suffix)
4317 {
4318         const struct config_enum_entry *entry = record->options;
4319         int             len = 0;
4320         char   *hintmsg;
4321
4322         if (!entry || !entry->name)
4323                 return NULL;                                    /* Should not happen */
4324
4325         while (entry && entry->name)
4326         {
4327                 len += strlen(entry->name) + 2; /* string and ", " */
4328                 entry++;
4329         }
4330
4331         hintmsg = palloc(len + strlen(prefix) + strlen(suffix) + 2);
4332
4333         strcpy(hintmsg, prefix);
4334
4335         entry = record->options;
4336         while (entry && entry->name)
4337         {
4338                 strcat(hintmsg, entry->name);
4339                 strcat(hintmsg, ", ");
4340                 entry++;
4341         }
4342
4343         /* Replace final comma/space */
4344         hintmsg[strlen(hintmsg)-2] = '\0';
4345         strcat(hintmsg, suffix);
4346
4347         return hintmsg;
4348 }
4349
4350
4351 /*
4352  * Call a GucStringAssignHook function, being careful to free the
4353  * "newval" string if the hook ereports.
4354  *
4355  * This is split out of set_config_option just to avoid the "volatile"
4356  * qualifiers that would otherwise have to be plastered all over.
4357  */
4358 static const char *
4359 call_string_assign_hook(GucStringAssignHook assign_hook,
4360                                                 char *newval, bool doit, GucSource source)
4361 {
4362         const char *result;
4363
4364         PG_TRY();
4365         {
4366                 result = (*assign_hook) (newval, doit, source);
4367         }
4368         PG_CATCH();
4369         {
4370                 free(newval);
4371                 PG_RE_THROW();
4372         }
4373         PG_END_TRY();
4374
4375         return result;
4376 }
4377
4378
4379 /*
4380  * Sets option `name' to given value. The value should be a string
4381  * which is going to be parsed and converted to the appropriate data
4382  * type.  The context and source parameters indicate in which context this
4383  * function is being called so it can apply the access restrictions
4384  * properly.
4385  *
4386  * If value is NULL, set the option to its default value (normally the
4387  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4388  *
4389  * action indicates whether to set the value globally in the session, locally
4390  * to the current top transaction, or just for the duration of a function call.
4391  *
4392  * If changeVal is false then don't really set the option but do all
4393  * the checks to see if it would work.
4394  *
4395  * If there is an error (non-existing option, invalid value) then an
4396  * ereport(ERROR) is thrown *unless* this is called in a context where we
4397  * don't want to ereport (currently, startup or SIGHUP config file reread).
4398  * In that case we write a suitable error message via ereport(LOG) and
4399  * return false. This is working around the deficiencies in the ereport
4400  * mechanism, so don't blame me.  In all other cases, the function
4401  * returns true, including cases where the input is valid but we chose
4402  * not to apply it because of context or source-priority considerations.
4403  *
4404  * See also SetConfigOption for an external interface.
4405  */
4406 bool
4407 set_config_option(const char *name, const char *value,
4408                                   GucContext context, GucSource source,
4409                                   GucAction action, bool changeVal)
4410 {
4411         struct config_generic *record;
4412         int                     elevel;
4413         bool            makeDefault;
4414
4415         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4416         {
4417                 /*
4418                  * To avoid cluttering the log, only the postmaster bleats loudly
4419                  * about problems with the config file.
4420                  */
4421                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4422         }
4423         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4424                 elevel = INFO;
4425         else
4426                 elevel = ERROR;
4427
4428         record = find_option(name, true, elevel);
4429         if (record == NULL)
4430         {
4431                 ereport(elevel,
4432                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4433                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4434                 return false;
4435         }
4436
4437         /*
4438          * If source is postgresql.conf, mark the found record with
4439          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4440          * that we do it even if changeVal is false, since ProcessConfigFile wants
4441          * the marking to occur during its testing pass.
4442          */
4443         if (source == PGC_S_FILE)
4444                 record->status |= GUC_IS_IN_FILE;
4445
4446         /*
4447          * Check if the option can be set at this time. See guc.h for the precise
4448          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4449          * context. In that case we just ignore the attempt and return true.
4450          */
4451         switch (record->context)
4452         {
4453                 case PGC_INTERNAL:
4454                         if (context == PGC_SIGHUP)
4455                                 return true;
4456                         if (context != PGC_INTERNAL)
4457                         {
4458                                 ereport(elevel,
4459                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4460                                                  errmsg("parameter \"%s\" cannot be changed",
4461                                                                 name)));
4462                                 return false;
4463                         }
4464                         break;
4465                 case PGC_POSTMASTER:
4466                         if (context == PGC_SIGHUP)
4467                         {
4468                                 /*
4469                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4470                                  * We can't change the setting, so give a warning if the DBA
4471                                  * tries to change it.  (Throwing an error would be more
4472                                  * consistent, but seems overly rigid.)
4473                                  */
4474                                 if (changeVal && !is_newvalue_equal(record, value))
4475                                         ereport(elevel,
4476                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4477                                                          errmsg("parameter \"%s\" cannot be changed after server start; configuration file change ignored",
4478                                                                         name)));
4479                                 return true;
4480                         }
4481                         if (context != PGC_POSTMASTER)
4482                         {
4483                                 ereport(elevel,
4484                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4485                                                  errmsg("parameter \"%s\" cannot be changed after server start",
4486                                                                 name)));
4487                                 return false;
4488                         }
4489                         break;
4490                 case PGC_SIGHUP:
4491                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4492                         {
4493                                 ereport(elevel,
4494                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4495                                                  errmsg("parameter \"%s\" cannot be changed now",
4496                                                                 name)));
4497                                 return false;
4498                         }
4499
4500                         /*
4501                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4502                          * can be changed after postmaster start". But there's nothing
4503                          * that prevents a crafty administrator from sending SIGHUP
4504                          * signals to individual backends only.
4505                          */
4506                         break;
4507                 case PGC_BACKEND:
4508                         if (context == PGC_SIGHUP)
4509                         {
4510                                 /*
4511                                  * If a PGC_BACKEND parameter is changed in the config file,
4512                                  * we want to accept the new value in the postmaster (whence
4513                                  * it will propagate to subsequently-started backends), but
4514                                  * ignore it in existing backends.      This is a tad klugy, but
4515                                  * necessary because we don't re-read the config file during
4516                                  * backend start.
4517                                  */
4518                                 if (IsUnderPostmaster)
4519                                         return true;
4520                         }
4521                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
4522                         {
4523                                 ereport(elevel,
4524                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4525                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4526                                                                 name)));
4527                                 return false;
4528                         }
4529                         break;
4530                 case PGC_SUSET:
4531                         if (context == PGC_USERSET || context == PGC_BACKEND)
4532                         {
4533                                 ereport(elevel,
4534                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4535                                                  errmsg("permission denied to set parameter \"%s\"",
4536                                                                 name)));
4537                                 return false;
4538                         }
4539                         break;
4540                 case PGC_USERSET:
4541                         /* always okay */
4542                         break;
4543         }
4544
4545         /*
4546          * Should we set reset/stacked values?  (If so, the behavior is not
4547          * transactional.)      This is done either when we get a default value from
4548          * the database's/user's/client's default settings or when we reset a
4549          * value to its default.
4550          */
4551         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4552                 ((value != NULL) || source == PGC_S_DEFAULT);
4553
4554         /*
4555          * Ignore attempted set if overridden by previously processed setting.
4556          * However, if changeVal is false then plow ahead anyway since we are
4557          * trying to find out if the value is potentially good, not actually use
4558          * it. Also keep going if makeDefault is true, since we may want to set
4559          * the reset/stacked values even if we can't set the variable itself.
4560          */
4561         if (record->source > source)
4562         {
4563                 if (changeVal && !makeDefault)
4564                 {
4565                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4566                                  name);
4567                         return true;
4568                 }
4569                 changeVal = false;
4570         }
4571
4572         /*
4573          * Evaluate value and set variable.
4574          */
4575         switch (record->vartype)
4576         {
4577                 case PGC_BOOL:
4578                         {
4579                                 struct config_bool *conf = (struct config_bool *) record;
4580                                 bool            newval;
4581
4582                                 if (value)
4583                                 {
4584                                         if (!parse_bool(value, &newval))
4585                                         {
4586                                                 ereport(elevel,
4587                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4588                                                   errmsg("parameter \"%s\" requires a Boolean value",
4589                                                                  name)));
4590                                                 return false;
4591                                         }
4592                                 }
4593                                 else if (source == PGC_S_DEFAULT)
4594                                         newval = conf->boot_val;
4595                                 else
4596                                 {
4597                                         newval = conf->reset_val;
4598                                         source = conf->gen.reset_source;
4599                                 }
4600
4601                                 if (conf->assign_hook)
4602                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4603                                         {
4604                                                 ereport(elevel,
4605                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4606                                                          errmsg("invalid value for parameter \"%s\": %d",
4607                                                                         name, (int) newval)));
4608                                                 return false;
4609                                         }
4610
4611                                 if (changeVal || makeDefault)
4612                                 {
4613                                         /* Save old value to support transaction abort */
4614                                         if (!makeDefault)
4615                                                 push_old_value(&conf->gen, action);
4616                                         if (changeVal)
4617                                         {
4618                                                 *conf->variable = newval;
4619                                                 conf->gen.source = source;
4620                                         }
4621                                         if (makeDefault)
4622                                         {
4623                                                 GucStack   *stack;
4624
4625                                                 if (conf->gen.reset_source <= source)
4626                                                 {
4627                                                         conf->reset_val = newval;
4628                                                         conf->gen.reset_source = source;
4629                                                 }
4630                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4631                                                 {
4632                                                         if (stack->source <= source)
4633                                                         {
4634                                                                 stack->prior.boolval = newval;
4635                                                                 stack->source = source;
4636                                                         }
4637                                                 }
4638                                         }
4639                                 }
4640                                 break;
4641                         }
4642
4643                 case PGC_INT:
4644                         {
4645                                 struct config_int *conf = (struct config_int *) record;
4646                                 int                     newval;
4647
4648                                 if (value)
4649                                 {
4650                                         const char *hintmsg;
4651
4652                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4653                                         {
4654                                                 ereport(elevel,
4655                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4656                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4657                                                                 name, value),
4658                                                                  hintmsg ? errhint(hintmsg) : 0));
4659                                                 return false;
4660                                         }
4661                                         if (newval < conf->min || newval > conf->max)
4662                                         {
4663                                                 ereport(elevel,
4664                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4665                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4666                                                                                 newval, name, conf->min, conf->max)));
4667                                                 return false;
4668                                         }
4669                                 }
4670                                 else if (source == PGC_S_DEFAULT)
4671                                         newval = conf->boot_val;
4672                                 else
4673                                 {
4674                                         newval = conf->reset_val;
4675                                         source = conf->gen.reset_source;
4676                                 }
4677
4678                                 if (conf->assign_hook)
4679                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4680                                         {
4681                                                 ereport(elevel,
4682                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4683                                                          errmsg("invalid value for parameter \"%s\": %d",
4684                                                                         name, newval)));
4685                                                 return false;
4686                                         }
4687
4688                                 if (changeVal || makeDefault)
4689                                 {
4690                                         /* Save old value to support transaction abort */
4691                                         if (!makeDefault)
4692                                                 push_old_value(&conf->gen, action);
4693                                         if (changeVal)
4694                                         {
4695                                                 *conf->variable = newval;
4696                                                 conf->gen.source = source;
4697                                         }
4698                                         if (makeDefault)
4699                                         {
4700                                                 GucStack   *stack;
4701
4702                                                 if (conf->gen.reset_source <= source)
4703                                                 {
4704                                                         conf->reset_val = newval;
4705                                                         conf->gen.reset_source = source;
4706                                                 }
4707                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4708                                                 {
4709                                                         if (stack->source <= source)
4710                                                         {
4711                                                                 stack->prior.intval = newval;
4712                                                                 stack->source = source;
4713                                                         }
4714                                                 }
4715                                         }
4716                                 }
4717                                 break;
4718                         }
4719
4720                 case PGC_REAL:
4721                         {
4722                                 struct config_real *conf = (struct config_real *) record;
4723                                 double          newval;
4724
4725                                 if (value)
4726                                 {
4727                                         if (!parse_real(value, &newval))
4728                                         {
4729                                                 ereport(elevel,
4730                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4731                                                   errmsg("parameter \"%s\" requires a numeric value",
4732                                                                  name)));
4733                                                 return false;
4734                                         }
4735                                         if (newval < conf->min || newval > conf->max)
4736                                         {
4737                                                 ereport(elevel,
4738                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4739                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4740                                                                                 newval, name, conf->min, conf->max)));
4741                                                 return false;
4742                                         }
4743                                 }
4744                                 else if (source == PGC_S_DEFAULT)
4745                                         newval = conf->boot_val;
4746                                 else
4747                                 {
4748                                         newval = conf->reset_val;
4749                                         source = conf->gen.reset_source;
4750                                 }
4751
4752                                 if (conf->assign_hook)
4753                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4754                                         {
4755                                                 ereport(elevel,
4756                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4757                                                          errmsg("invalid value for parameter \"%s\": %g",
4758                                                                         name, newval)));
4759                                                 return false;
4760                                         }
4761
4762                                 if (changeVal || makeDefault)
4763                                 {
4764                                         /* Save old value to support transaction abort */
4765                                         if (!makeDefault)
4766                                                 push_old_value(&conf->gen, action);
4767                                         if (changeVal)
4768                                         {
4769                                                 *conf->variable = newval;
4770                                                 conf->gen.source = source;
4771                                         }
4772                                         if (makeDefault)
4773                                         {
4774                                                 GucStack   *stack;
4775
4776                                                 if (conf->gen.reset_source <= source)
4777                                                 {
4778                                                         conf->reset_val = newval;
4779                                                         conf->gen.reset_source = source;
4780                                                 }
4781                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4782                                                 {
4783                                                         if (stack->source <= source)
4784                                                         {
4785                                                                 stack->prior.realval = newval;
4786                                                                 stack->source = source;
4787                                                         }
4788                                                 }
4789                                         }
4790                                 }
4791                                 break;
4792                         }
4793
4794                 case PGC_STRING:
4795                         {
4796                                 struct config_string *conf = (struct config_string *) record;
4797                                 char       *newval;
4798
4799                                 if (value)
4800                                 {
4801                                         newval = guc_strdup(elevel, value);
4802                                         if (newval == NULL)
4803                                                 return false;
4804
4805                                         /*
4806                                          * The only sort of "parsing" check we need to do is apply
4807                                          * truncation if GUC_IS_NAME.
4808                                          */
4809                                         if (conf->gen.flags & GUC_IS_NAME)
4810                                                 truncate_identifier(newval, strlen(newval), true);
4811                                 }
4812                                 else if (source == PGC_S_DEFAULT)
4813                                 {
4814                                         if (conf->boot_val == NULL)
4815                                                 newval = NULL;
4816                                         else
4817                                         {
4818                                                 newval = guc_strdup(elevel, conf->boot_val);
4819                                                 if (newval == NULL)
4820                                                         return false;
4821                                         }
4822                                 }
4823                                 else
4824                                 {
4825                                         /*
4826                                          * We could possibly avoid strdup here, but easier to make
4827                                          * this case work the same as the normal assignment case;
4828                                          * note the possible free of newval below.
4829                                          */
4830                                         if (conf->reset_val == NULL)
4831                                                 newval = NULL;
4832                                         else
4833                                         {
4834                                                 newval = guc_strdup(elevel, conf->reset_val);
4835                                                 if (newval == NULL)
4836                                                         return false;
4837                                         }
4838                                         source = conf->gen.reset_source;
4839                                 }
4840
4841                                 if (conf->assign_hook && newval)
4842                                 {
4843                                         const char *hookresult;
4844
4845                                         /*
4846                                          * If the hook ereports, we have to make sure we free
4847                                          * newval, else it will be a permanent memory leak.
4848                                          */
4849                                         hookresult = call_string_assign_hook(conf->assign_hook,
4850                                                                                                                  newval,
4851                                                                                                                  changeVal,
4852                                                                                                                  source);
4853                                         if (hookresult == NULL)
4854                                         {
4855                                                 free(newval);
4856                                                 ereport(elevel,
4857                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4858                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4859                                                                 name, value ? value : "")));
4860                                                 return false;
4861                                         }
4862                                         else if (hookresult != newval)
4863                                         {
4864                                                 free(newval);
4865
4866                                                 /*
4867                                                  * Having to cast away const here is annoying, but the
4868                                                  * alternative is to declare assign_hooks as returning
4869                                                  * char*, which would mean they'd have to cast away
4870                                                  * const, or as both taking and returning char*, which
4871                                                  * doesn't seem attractive either --- we don't want
4872                                                  * them to scribble on the passed str.
4873                                                  */
4874                                                 newval = (char *) hookresult;
4875                                         }
4876                                 }
4877
4878                                 if (changeVal || makeDefault)
4879                                 {
4880                                         /* Save old value to support transaction abort */
4881                                         if (!makeDefault)
4882                                                 push_old_value(&conf->gen, action);
4883                                         if (changeVal)
4884                                         {
4885                                                 set_string_field(conf, conf->variable, newval);
4886                                                 conf->gen.source = source;
4887                                         }
4888                                         if (makeDefault)
4889                                         {
4890                                                 GucStack   *stack;
4891
4892                                                 if (conf->gen.reset_source <= source)
4893                                                 {
4894                                                         set_string_field(conf, &conf->reset_val, newval);
4895                                                         conf->gen.reset_source = source;
4896                                                 }
4897                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4898                                                 {
4899                                                         if (stack->source <= source)
4900                                                         {
4901                                                                 set_string_field(conf, &stack->prior.stringval,
4902                                                                                                  newval);
4903                                                                 stack->source = source;
4904                                                         }
4905                                                 }
4906                                                 /* Perhaps we didn't install newval anywhere */
4907                                                 if (newval && !string_field_used(conf, newval))
4908                                                         free(newval);
4909                                         }
4910                                 }
4911                                 else if (newval)
4912                                         free(newval);
4913                                 break;
4914                         }
4915                 case PGC_ENUM:
4916                         {
4917                                 struct config_enum *conf = (struct config_enum *) record;
4918                                 int                     newval;
4919
4920                                 if (value)
4921                                 {
4922                                         if (!config_enum_lookup_by_name(conf, value, &newval))
4923                                         {
4924                                                 char *hintmsg = config_enum_get_options(conf, "Available values: ", ".");
4925
4926                                                 ereport(elevel,
4927                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4928                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4929                                                                                 name, value),
4930                                                                  hintmsg ? errhint(hintmsg) : 0));
4931
4932                                                 if (hintmsg)
4933                                                         pfree(hintmsg);
4934                                                 return false;
4935                                         }
4936                                 }
4937                                 else if (source == PGC_S_DEFAULT)
4938                                         newval = conf->boot_val;
4939                                 else
4940                                 {
4941                                         newval = conf->reset_val;
4942                                         source = conf->gen.reset_source;
4943                                 }
4944
4945                                 if (conf->assign_hook)
4946                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4947                                         {
4948                                                 ereport(elevel,
4949                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4950                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4951                                                                                 name,
4952                                                                                 config_enum_lookup_by_value(conf, newval))));
4953                                                 return false;
4954                                         }
4955
4956                                 if (changeVal || makeDefault)
4957                                 {
4958                                         /* Save old value to support transaction abort */
4959                                         if (!makeDefault)
4960                                                 push_old_value(&conf->gen, action);
4961                                         if (changeVal)
4962                                         {
4963                                                 *conf->variable = newval;
4964                                                 conf->gen.source = source;
4965                                         }
4966                                         if (makeDefault)
4967                                         {
4968                                                 GucStack   *stack;
4969
4970                                                 if (conf->gen.reset_source <= source)
4971                                                 {
4972                                                         conf->reset_val = newval;
4973                                                         conf->gen.reset_source = source;
4974                                                 }
4975                                                 for (stack = conf->gen.stack; stack; stack = stack->prev)
4976                                                 {
4977                                                         if (stack->source <= source)
4978                                                         {
4979                                                                 stack->prior.enumval = newval;
4980                                                                 stack->source = source;
4981                                                         }
4982                                                 }
4983                                         }
4984                                 }
4985                                 break;
4986                         }
4987         }
4988
4989         if (changeVal && (record->flags & GUC_REPORT))
4990                 ReportGUCOption(record);
4991
4992         return true;
4993 }
4994
4995
4996 /*
4997  * Set a config option to the given value. See also set_config_option,
4998  * this is just the wrapper to be called from outside GUC.      NB: this
4999  * is used only for non-transactional operations.
5000  */
5001 void
5002 SetConfigOption(const char *name, const char *value,
5003                                 GucContext context, GucSource source)
5004 {
5005         (void) set_config_option(name, value, context, source,
5006                                                          GUC_ACTION_SET, true);
5007 }
5008
5009
5010
5011 /*
5012  * Fetch the current value of the option `name'. If the option doesn't exist,
5013  * throw an ereport and don't return.
5014  *
5015  * The string is *not* allocated for modification and is really only
5016  * valid until the next call to configuration related functions.
5017  */
5018 const char *
5019 GetConfigOption(const char *name)
5020 {
5021         struct config_generic *record;
5022         static char buffer[256];
5023
5024         record = find_option(name, false, ERROR);
5025         if (record == NULL)
5026                 ereport(ERROR,
5027                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5028                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5029         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5030                 ereport(ERROR,
5031                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5032                                  errmsg("must be superuser to examine \"%s\"", name)));
5033
5034         switch (record->vartype)
5035         {
5036                 case PGC_BOOL:
5037                         return *((struct config_bool *) record)->variable ? "on" : "off";
5038
5039                 case PGC_INT:
5040                         snprintf(buffer, sizeof(buffer), "%d",
5041                                          *((struct config_int *) record)->variable);
5042                         return buffer;
5043
5044                 case PGC_REAL:
5045                         snprintf(buffer, sizeof(buffer), "%g",
5046                                          *((struct config_real *) record)->variable);
5047                         return buffer;
5048
5049                 case PGC_STRING:
5050                         return *((struct config_string *) record)->variable;
5051
5052                 case PGC_ENUM:
5053                         return config_enum_lookup_by_value((struct config_enum *) record,
5054                                                                                         *((struct config_enum *) record)->variable);
5055         }
5056         return NULL;
5057 }
5058
5059 /*
5060  * Get the RESET value associated with the given option.
5061  *
5062  * Note: this is not re-entrant, due to use of static result buffer;
5063  * not to mention that a string variable could have its reset_val changed.
5064  * Beware of assuming the result value is good for very long.
5065  */
5066 const char *
5067 GetConfigOptionResetString(const char *name)
5068 {
5069         struct config_generic *record;
5070         static char buffer[256];
5071
5072         record = find_option(name, false, ERROR);
5073         if (record == NULL)
5074                 ereport(ERROR,
5075                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5076                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5077         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5078                 ereport(ERROR,
5079                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5080                                  errmsg("must be superuser to examine \"%s\"", name)));
5081
5082         switch (record->vartype)
5083         {
5084                 case PGC_BOOL:
5085                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5086
5087                 case PGC_INT:
5088                         snprintf(buffer, sizeof(buffer), "%d",
5089                                          ((struct config_int *) record)->reset_val);
5090                         return buffer;
5091
5092                 case PGC_REAL:
5093                         snprintf(buffer, sizeof(buffer), "%g",
5094                                          ((struct config_real *) record)->reset_val);
5095                         return buffer;
5096
5097                 case PGC_STRING:
5098                         return ((struct config_string *) record)->reset_val;
5099
5100                 case PGC_ENUM:
5101                         return config_enum_lookup_by_value((struct config_enum *) record,
5102                                                                                     ((struct config_enum *) record)->reset_val);
5103         }
5104         return NULL;
5105 }
5106
5107 /*
5108  * Detect whether the given configuration option can only be set by
5109  * a superuser.
5110  */
5111 bool
5112 IsSuperuserConfigOption(const char *name)
5113 {
5114         struct config_generic *record;
5115
5116         record = find_option(name, false, ERROR);
5117         /* On an unrecognized name, don't error, just return false. */
5118         if (record == NULL)
5119                 return false;
5120         return (record->context == PGC_SUSET);
5121 }
5122
5123
5124 /*
5125  * GUC_complaint_elevel
5126  *              Get the ereport error level to use in an assign_hook's error report.
5127  *
5128  * This should be used by assign hooks that want to emit a custom error
5129  * report (in addition to the generic "invalid value for option FOO" that
5130  * guc.c will provide).  Note that the result might be ERROR or a lower
5131  * level, so the caller must be prepared for control to return from ereport,
5132  * or not.  If control does return, return false/NULL from the hook function.
5133  *
5134  * At some point it'd be nice to replace this with a mechanism that allows
5135  * the custom message to become the DETAIL line of guc.c's generic message.
5136  */
5137 int
5138 GUC_complaint_elevel(GucSource source)
5139 {
5140         int                     elevel;
5141
5142         if (source == PGC_S_FILE)
5143         {
5144                 /*
5145                  * To avoid cluttering the log, only the postmaster bleats loudly
5146                  * about problems with the config file.
5147                  */
5148                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5149         }
5150         else if (source == PGC_S_OVERRIDE)
5151         {
5152                 /*
5153                  * If we're a postmaster child, this is probably "undo" during
5154                  * transaction abort, so we don't want to clutter the log.  There's
5155                  * a small chance of a real problem with an OVERRIDE setting,
5156                  * though, so suppressing the message entirely wouldn't be desirable.
5157                  */
5158                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5159         }
5160         else if (source < PGC_S_INTERACTIVE)
5161                 elevel = LOG;
5162         else
5163                 elevel = ERROR;
5164
5165         return elevel;
5166 }
5167
5168
5169 /*
5170  * flatten_set_variable_args
5171  *              Given a parsenode List as emitted by the grammar for SET,
5172  *              convert to the flat string representation used by GUC.
5173  *
5174  * We need to be told the name of the variable the args are for, because
5175  * the flattening rules vary (ugh).
5176  *
5177  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5178  * a palloc'd string.
5179  */
5180 static char *
5181 flatten_set_variable_args(const char *name, List *args)
5182 {
5183         struct config_generic *record;
5184         int                     flags;
5185         StringInfoData buf;
5186         ListCell   *l;
5187
5188         /* Fast path if just DEFAULT */
5189         if (args == NIL)
5190                 return NULL;
5191
5192         /* Else get flags for the variable */
5193         record = find_option(name, true, ERROR);
5194         if (record == NULL)
5195                 ereport(ERROR,
5196                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5197                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5198
5199         flags = record->flags;
5200
5201         /* Complain if list input and non-list variable */
5202         if ((flags & GUC_LIST_INPUT) == 0 &&
5203                 list_length(args) != 1)
5204                 ereport(ERROR,
5205                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5206                                  errmsg("SET %s takes only one argument", name)));
5207
5208         initStringInfo(&buf);
5209
5210         /*
5211          * Each list member may be a plain A_Const node, or an A_Const within a
5212          * TypeCast; the latter case is supported only for ConstInterval
5213          * arguments (for SET TIME ZONE).
5214          */
5215         foreach(l, args)
5216         {
5217                 Node       *arg = (Node *) lfirst(l);
5218                 char       *val;
5219                 TypeName   *typename = NULL;
5220                 A_Const    *con;
5221
5222                 if (l != list_head(args))
5223                         appendStringInfo(&buf, ", ");
5224
5225                 if (IsA(arg, TypeCast))
5226                 {
5227                         TypeCast *tc = (TypeCast *) arg;
5228
5229                         arg = tc->arg;
5230                         typename = tc->typename;
5231                 }
5232
5233                 if (!IsA(arg, A_Const))
5234                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5235                 con = (A_Const *) arg;
5236
5237                 switch (nodeTag(&con->val))
5238                 {
5239                         case T_Integer:
5240                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5241                                 break;
5242                         case T_Float:
5243                                 /* represented as a string, so just copy it */
5244                                 appendStringInfoString(&buf, strVal(&con->val));
5245                                 break;
5246                         case T_String:
5247                                 val = strVal(&con->val);
5248                                 if (typename != NULL)
5249                                 {
5250                                         /*
5251                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5252                                          * to interval and back to normalize the value and account
5253                                          * for any typmod.
5254                                          */
5255                                         Oid                     typoid;
5256                                         int32           typmod;
5257                                         Datum           interval;
5258                                         char       *intervalout;
5259
5260                                         typoid = typenameTypeId(NULL, typename, &typmod);
5261                                         Assert(typoid == INTERVALOID);
5262
5263                                         interval =
5264                                                 DirectFunctionCall3(interval_in,
5265                                                                                         CStringGetDatum(val),
5266                                                                                         ObjectIdGetDatum(InvalidOid),
5267                                                                                         Int32GetDatum(typmod));
5268
5269                                         intervalout =
5270                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5271                                                                                                                         interval));
5272                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5273                                 }
5274                                 else
5275                                 {
5276                                         /*
5277                                          * Plain string literal or identifier.  For quote mode,
5278                                          * quote it if it's not a vanilla identifier.
5279                                          */
5280                                         if (flags & GUC_LIST_QUOTE)
5281                                                 appendStringInfoString(&buf, quote_identifier(val));
5282                                         else
5283                                                 appendStringInfoString(&buf, val);
5284                                 }
5285                                 break;
5286                         default:
5287                                 elog(ERROR, "unrecognized node type: %d",
5288                                          (int) nodeTag(&con->val));
5289                                 break;
5290                 }
5291         }
5292
5293         return buf.data;
5294 }
5295
5296
5297 /*
5298  * SET command
5299  */
5300 void
5301 ExecSetVariableStmt(VariableSetStmt *stmt)
5302 {
5303         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5304
5305         switch (stmt->kind)
5306         {
5307                 case VAR_SET_VALUE:
5308                 case VAR_SET_CURRENT:
5309                         set_config_option(stmt->name,
5310                                                           ExtractSetVariableArgs(stmt),
5311                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5312                                                           PGC_S_SESSION,
5313                                                           action,
5314                                                           true);
5315                         break;
5316                 case VAR_SET_MULTI:
5317
5318                         /*
5319                          * Special case for special SQL syntax that effectively sets more
5320                          * than one variable per statement.
5321                          */
5322                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5323                         {
5324                                 ListCell   *head;
5325
5326                                 foreach(head, stmt->args)
5327                                 {
5328                                         DefElem    *item = (DefElem *) lfirst(head);
5329
5330                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5331                                                 SetPGVariable("transaction_isolation",
5332                                                                           list_make1(item->arg), stmt->is_local);
5333                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5334                                                 SetPGVariable("transaction_read_only",
5335                                                                           list_make1(item->arg), stmt->is_local);
5336                                         else
5337                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5338                                                          item->defname);
5339                                 }
5340                         }
5341                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5342                         {
5343                                 ListCell   *head;
5344
5345                                 foreach(head, stmt->args)
5346                                 {
5347                                         DefElem    *item = (DefElem *) lfirst(head);
5348
5349                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5350                                                 SetPGVariable("default_transaction_isolation",
5351                                                                           list_make1(item->arg), stmt->is_local);
5352                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5353                                                 SetPGVariable("default_transaction_read_only",
5354                                                                           list_make1(item->arg), stmt->is_local);
5355                                         else
5356                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5357                                                          item->defname);
5358                                 }
5359                         }
5360                         else
5361                                 elog(ERROR, "unexpected SET MULTI element: %s",
5362                                          stmt->name);
5363                         break;
5364                 case VAR_SET_DEFAULT:
5365                 case VAR_RESET:
5366                         set_config_option(stmt->name,
5367                                                           NULL,
5368                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5369                                                           PGC_S_SESSION,
5370                                                           action,
5371                                                           true);
5372                         break;
5373                 case VAR_RESET_ALL:
5374                         ResetAllOptions();
5375                         break;
5376         }
5377 }
5378
5379 /*
5380  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5381  * The result is palloc'd.
5382  *
5383  * This is exported for use by actions such as ALTER ROLE SET.
5384  */
5385 char *
5386 ExtractSetVariableArgs(VariableSetStmt *stmt)
5387 {
5388         switch (stmt->kind)
5389         {
5390                 case VAR_SET_VALUE:
5391                         return flatten_set_variable_args(stmt->name, stmt->args);
5392                 case VAR_SET_CURRENT:
5393                         return GetConfigOptionByName(stmt->name, NULL);
5394                 default:
5395                         return NULL;
5396         }
5397 }
5398
5399 /*
5400  * SetPGVariable - SET command exported as an easily-C-callable function.
5401  *
5402  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5403  * by passing args == NIL), but not SET FROM CURRENT functionality.
5404  */
5405 void
5406 SetPGVariable(const char *name, List *args, bool is_local)
5407 {
5408         char       *argstring = flatten_set_variable_args(name, args);
5409
5410         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5411         set_config_option(name,
5412                                           argstring,
5413                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5414                                           PGC_S_SESSION,
5415                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5416                                           true);
5417 }
5418
5419 /*
5420  * SET command wrapped as a SQL callable function.
5421  */
5422 Datum
5423 set_config_by_name(PG_FUNCTION_ARGS)
5424 {
5425         char       *name;
5426         char       *value;
5427         char       *new_value;
5428         bool            is_local;
5429
5430         if (PG_ARGISNULL(0))
5431                 ereport(ERROR,
5432                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5433                                  errmsg("SET requires parameter name")));
5434
5435         /* Get the GUC variable name */
5436         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5437
5438         /* Get the desired value or set to NULL for a reset request */
5439         if (PG_ARGISNULL(1))
5440                 value = NULL;
5441         else
5442                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5443
5444         /*
5445          * Get the desired state of is_local. Default to false if provided value
5446          * is NULL
5447          */
5448         if (PG_ARGISNULL(2))
5449                 is_local = false;
5450         else
5451                 is_local = PG_GETARG_BOOL(2);
5452
5453         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5454         set_config_option(name,
5455                                           value,
5456                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5457                                           PGC_S_SESSION,
5458                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5459                                           true);
5460
5461         /* get the new current value */
5462         new_value = GetConfigOptionByName(name, NULL);
5463
5464         /* Convert return string to text */
5465         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5466 }
5467
5468
5469 /*
5470  * Common code for DefineCustomXXXVariable subroutines: allocate the
5471  * new variable's config struct and fill in generic fields.
5472  */
5473 static struct config_generic *
5474 init_custom_variable(const char *name,
5475                                          const char *short_desc,
5476                                          const char *long_desc,
5477                                          GucContext context,
5478                                          enum config_type type,
5479                                          size_t sz)
5480 {
5481         struct config_generic *gen;
5482
5483         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5484         memset(gen, 0, sz);
5485
5486         gen->name = guc_strdup(ERROR, name);
5487         gen->context = context;
5488         gen->group = CUSTOM_OPTIONS;
5489         gen->short_desc = short_desc;
5490         gen->long_desc = long_desc;
5491         gen->vartype = type;
5492
5493         return gen;
5494 }
5495
5496 /*
5497  * Common code for DefineCustomXXXVariable subroutines: insert the new
5498  * variable into the GUC variable array, replacing any placeholder.
5499  */
5500 static void
5501 define_custom_variable(struct config_generic * variable)
5502 {
5503         const char *name = variable->name;
5504         const char **nameAddr = &name;
5505         const char *value;
5506         struct config_string *pHolder;
5507         struct config_generic **res;
5508
5509         res = (struct config_generic **) bsearch((void *) &nameAddr,
5510                                                                                          (void *) guc_variables,
5511                                                                                          num_guc_variables,
5512                                                                                          sizeof(struct config_generic *),
5513                                                                                          guc_var_compare);
5514         if (res == NULL)
5515         {
5516                 /* No placeholder to replace, so just add it */
5517                 add_guc_variable(variable, ERROR);
5518                 return;
5519         }
5520
5521         /*
5522          * This better be a placeholder
5523          */
5524         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5525                 ereport(ERROR,
5526                                 (errcode(ERRCODE_INTERNAL_ERROR),
5527                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5528
5529         Assert((*res)->vartype == PGC_STRING);
5530         pHolder = (struct config_string *) (*res);
5531
5532         /*
5533          * Replace the placeholder. We aren't changing the name, so no re-sorting
5534          * is necessary
5535          */
5536         *res = variable;
5537
5538         /*
5539          * Assign the string value stored in the placeholder to the real variable.
5540          *
5541          * XXX this is not really good enough --- it should be a nontransactional
5542          * assignment, since we don't want it to roll back if the current xact
5543          * fails later.
5544          */
5545         value = *pHolder->variable;
5546
5547         if (value)
5548                 set_config_option(name, value,
5549                                                   pHolder->gen.context, pHolder->gen.source,
5550                                                   GUC_ACTION_SET, true);
5551
5552         /*
5553          * Free up as much as we conveniently can of the placeholder structure
5554          * (this neglects any stack items...)
5555          */
5556         set_string_field(pHolder, pHolder->variable, NULL);
5557         set_string_field(pHolder, &pHolder->reset_val, NULL);
5558
5559         free(pHolder);
5560 }
5561
5562 void
5563 DefineCustomBoolVariable(const char *name,
5564                                                  const char *short_desc,
5565                                                  const char *long_desc,
5566                                                  bool *valueAddr,
5567                                                  GucContext context,
5568                                                  GucBoolAssignHook assign_hook,
5569                                                  GucShowHook show_hook)
5570 {
5571         struct config_bool *var;
5572
5573         var = (struct config_bool *)
5574                 init_custom_variable(name, short_desc, long_desc, context,
5575                                                          PGC_BOOL, sizeof(struct config_bool));
5576         var->variable = valueAddr;
5577         var->boot_val = *valueAddr;
5578         var->reset_val = *valueAddr;
5579         var->assign_hook = assign_hook;
5580         var->show_hook = show_hook;
5581         define_custom_variable(&var->gen);
5582 }
5583
5584 void
5585 DefineCustomIntVariable(const char *name,
5586                                                 const char *short_desc,
5587                                                 const char *long_desc,
5588                                                 int *valueAddr,
5589                                                 int minValue,
5590                                                 int maxValue,
5591                                                 GucContext context,
5592                                                 GucIntAssignHook assign_hook,
5593                                                 GucShowHook show_hook)
5594 {
5595         struct config_int *var;
5596
5597         var = (struct config_int *)
5598                 init_custom_variable(name, short_desc, long_desc, context,
5599                                                          PGC_INT, sizeof(struct config_int));
5600         var->variable = valueAddr;
5601         var->boot_val = *valueAddr;
5602         var->reset_val = *valueAddr;
5603         var->min = minValue;
5604         var->max = maxValue;
5605         var->assign_hook = assign_hook;
5606         var->show_hook = show_hook;
5607         define_custom_variable(&var->gen);
5608 }
5609
5610 void
5611 DefineCustomRealVariable(const char *name,
5612                                                  const char *short_desc,
5613                                                  const char *long_desc,
5614                                                  double *valueAddr,
5615                                                  double minValue,
5616                                                  double maxValue,
5617                                                  GucContext context,
5618                                                  GucRealAssignHook assign_hook,
5619                                                  GucShowHook show_hook)
5620 {
5621         struct config_real *var;
5622
5623         var = (struct config_real *)
5624                 init_custom_variable(name, short_desc, long_desc, context,
5625                                                          PGC_REAL, sizeof(struct config_real));
5626         var->variable = valueAddr;
5627         var->boot_val = *valueAddr;
5628         var->reset_val = *valueAddr;
5629         var->min = minValue;
5630         var->max = maxValue;
5631         var->assign_hook = assign_hook;
5632         var->show_hook = show_hook;
5633         define_custom_variable(&var->gen);
5634 }
5635
5636 void
5637 DefineCustomStringVariable(const char *name,
5638                                                    const char *short_desc,
5639                                                    const char *long_desc,
5640                                                    char **valueAddr,
5641                                                    GucContext context,
5642                                                    GucStringAssignHook assign_hook,
5643                                                    GucShowHook show_hook)
5644 {
5645         struct config_string *var;
5646
5647         var = (struct config_string *)
5648                 init_custom_variable(name, short_desc, long_desc, context,
5649                                                          PGC_STRING, sizeof(struct config_string));
5650         var->variable = valueAddr;
5651         var->boot_val = *valueAddr;
5652         /* we could probably do without strdup, but keep it like normal case */
5653         if (var->boot_val)
5654                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5655         var->assign_hook = assign_hook;
5656         var->show_hook = show_hook;
5657         define_custom_variable(&var->gen);
5658 }
5659
5660 void
5661 DefineCustomEnumVariable(const char *name,
5662                                                  const char *short_desc,
5663                                                  const char *long_desc,
5664                                                  int *valueAddr,
5665                                                  const struct config_enum_entry *options,
5666                                                  GucContext context,
5667                                                  GucEnumAssignHook assign_hook,
5668                                                  GucShowHook show_hook)
5669 {
5670         struct config_enum *var;
5671
5672         var = (struct config_enum *)
5673                 init_custom_variable(name, short_desc, long_desc, context,
5674                                                          PGC_ENUM, sizeof(struct config_enum));
5675         var->variable = valueAddr;
5676         var->boot_val = *valueAddr;
5677         var->reset_val = *valueAddr;
5678         var->options = options;
5679         var->assign_hook = assign_hook;
5680         var->show_hook = show_hook;
5681         define_custom_variable(&var->gen);
5682 }
5683
5684 void
5685 EmitWarningsOnPlaceholders(const char *className)
5686 {
5687         struct config_generic **vars = guc_variables;
5688         struct config_generic **last = vars + num_guc_variables;
5689
5690         int                     nameLen = strlen(className);
5691
5692         while (vars < last)
5693         {
5694                 struct config_generic *var = *vars++;
5695
5696                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5697                         strncmp(className, var->name, nameLen) == 0 &&
5698                         var->name[nameLen] == GUC_QUALIFIER_SEPARATOR)
5699                 {
5700                         ereport(INFO,
5701                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5702                                          errmsg("unrecognized configuration parameter \"%s\"", var->name)));
5703                 }
5704         }
5705 }
5706
5707
5708 /*
5709  * SHOW command
5710  */
5711 void
5712 GetPGVariable(const char *name, DestReceiver *dest)
5713 {
5714         if (guc_name_compare(name, "all") == 0)
5715                 ShowAllGUCConfig(dest);
5716         else
5717                 ShowGUCConfigOption(name, dest);
5718 }
5719
5720 TupleDesc
5721 GetPGVariableResultDesc(const char *name)
5722 {
5723         TupleDesc       tupdesc;
5724
5725         if (guc_name_compare(name, "all") == 0)
5726         {
5727                 /* need a tuple descriptor representing three TEXT columns */
5728                 tupdesc = CreateTemplateTupleDesc(3, false);
5729                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5730                                                    TEXTOID, -1, 0);
5731                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5732                                                    TEXTOID, -1, 0);
5733                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5734                                                    TEXTOID, -1, 0);
5735
5736         }
5737         else
5738         {
5739                 const char *varname;
5740
5741                 /* Get the canonical spelling of name */
5742                 (void) GetConfigOptionByName(name, &varname);
5743
5744                 /* need a tuple descriptor representing a single TEXT column */
5745                 tupdesc = CreateTemplateTupleDesc(1, false);
5746                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5747                                                    TEXTOID, -1, 0);
5748         }
5749         return tupdesc;
5750 }
5751
5752
5753 /*
5754  * SHOW command
5755  */
5756 static void
5757 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5758 {
5759         TupOutputState *tstate;
5760         TupleDesc       tupdesc;
5761         const char *varname;
5762         char       *value;
5763
5764         /* Get the value and canonical spelling of name */
5765         value = GetConfigOptionByName(name, &varname);
5766
5767         /* need a tuple descriptor representing a single TEXT column */
5768         tupdesc = CreateTemplateTupleDesc(1, false);
5769         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5770                                            TEXTOID, -1, 0);
5771
5772         /* prepare for projection of tuples */
5773         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5774
5775         /* Send it */
5776         do_text_output_oneline(tstate, value);
5777
5778         end_tup_output(tstate);
5779 }
5780
5781 /*
5782  * SHOW ALL command
5783  */
5784 static void
5785 ShowAllGUCConfig(DestReceiver *dest)
5786 {
5787         bool            am_superuser = superuser();
5788         int                     i;
5789         TupOutputState *tstate;
5790         TupleDesc       tupdesc;
5791         char       *values[3];
5792
5793         /* need a tuple descriptor representing three TEXT columns */
5794         tupdesc = CreateTemplateTupleDesc(3, false);
5795         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5796                                            TEXTOID, -1, 0);
5797         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5798                                            TEXTOID, -1, 0);
5799         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5800                                            TEXTOID, -1, 0);
5801
5802
5803         /* prepare for projection of tuples */
5804         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5805
5806         for (i = 0; i < num_guc_variables; i++)
5807         {
5808                 struct config_generic *conf = guc_variables[i];
5809
5810                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
5811                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
5812                         continue;
5813
5814                 /* assign to the values array */
5815                 values[0] = (char *) conf->name;
5816                 values[1] = _ShowOption(conf, true);
5817                 values[2] = (char *) conf->short_desc;
5818
5819                 /* send it to dest */
5820                 do_tup_output(tstate, values);
5821
5822                 /* clean up */
5823                 if (values[1] != NULL)
5824                         pfree(values[1]);
5825         }
5826
5827         end_tup_output(tstate);
5828 }
5829
5830 /*
5831  * Return GUC variable value by name; optionally return canonical
5832  * form of name.  Return value is palloc'd.
5833  */
5834 char *
5835 GetConfigOptionByName(const char *name, const char **varname)
5836 {
5837         struct config_generic *record;
5838
5839         record = find_option(name, false, ERROR);
5840         if (record == NULL)
5841                 ereport(ERROR,
5842                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5843                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5844         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5845                 ereport(ERROR,
5846                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5847                                  errmsg("must be superuser to examine \"%s\"", name)));
5848
5849         if (varname)
5850                 *varname = record->name;
5851
5852         return _ShowOption(record, true);
5853 }
5854
5855 /*
5856  * Return GUC variable value by variable number; optionally return canonical
5857  * form of name.  Return value is palloc'd.
5858  */
5859 void
5860 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
5861 {
5862         char            buffer[256];
5863         struct config_generic *conf;
5864
5865         /* check requested variable number valid */
5866         Assert((varnum >= 0) && (varnum < num_guc_variables));
5867
5868         conf = guc_variables[varnum];
5869
5870         if (noshow)
5871         {
5872                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
5873                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
5874                         *noshow = true;
5875                 else
5876                         *noshow = false;
5877         }
5878
5879         /* first get the generic attributes */
5880
5881         /* name */
5882         values[0] = conf->name;
5883
5884         /* setting : use _ShowOption in order to avoid duplicating the logic */
5885         values[1] = _ShowOption(conf, false);
5886
5887         /* unit */
5888         if (conf->vartype == PGC_INT)
5889         {
5890                 static char buf[8];
5891
5892                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
5893                 {
5894                         case GUC_UNIT_KB:
5895                                 values[2] = "kB";
5896                                 break;
5897                         case GUC_UNIT_BLOCKS:
5898                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
5899                                 values[2] = buf;
5900                                 break;
5901                         case GUC_UNIT_XBLOCKS:
5902                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
5903                                 values[2] = buf;
5904                                 break;
5905                         case GUC_UNIT_MS:
5906                                 values[2] = "ms";
5907                                 break;
5908                         case GUC_UNIT_S:
5909                                 values[2] = "s";
5910                                 break;
5911                         case GUC_UNIT_MIN:
5912                                 values[2] = "min";
5913                                 break;
5914                         default:
5915                                 values[2] = "";
5916                                 break;
5917                 }
5918         }
5919         else
5920                 values[2] = NULL;
5921
5922         /* group */
5923         values[3] = config_group_names[conf->group];
5924
5925         /* short_desc */
5926         values[4] = conf->short_desc;
5927
5928         /* extra_desc */
5929         values[5] = conf->long_desc;
5930
5931         /* context */
5932         values[6] = GucContext_Names[conf->context];
5933
5934         /* vartype */
5935         values[7] = config_type_names[conf->vartype];
5936
5937         /* source */
5938         values[8] = GucSource_Names[conf->source];
5939
5940         /* now get the type specifc attributes */
5941         switch (conf->vartype)
5942         {
5943                 case PGC_BOOL:
5944                         {
5945                                 /* min_val */
5946                                 values[9] = NULL;
5947
5948                                 /* max_val */
5949                                 values[10] = NULL;
5950
5951                                 /* enumvals */
5952                                 values[11] = NULL;
5953                         }
5954                         break;
5955
5956                 case PGC_INT:
5957                         {
5958                                 struct config_int *lconf = (struct config_int *) conf;
5959
5960                                 /* min_val */
5961                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
5962                                 values[9] = pstrdup(buffer);
5963
5964                                 /* max_val */
5965                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
5966                                 values[10] = pstrdup(buffer);
5967
5968                                 /* enumvals */
5969                                 values[11] = NULL;
5970                         }
5971                         break;
5972
5973                 case PGC_REAL:
5974                         {
5975                                 struct config_real *lconf = (struct config_real *) conf;
5976
5977                                 /* min_val */
5978                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
5979                                 values[9] = pstrdup(buffer);
5980
5981                                 /* max_val */
5982                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
5983                                 values[10] = pstrdup(buffer);
5984
5985                                 /* enumvals */
5986                                 values[11] = NULL;
5987                         }
5988                         break;
5989
5990                 case PGC_STRING:
5991                         {
5992                                 /* min_val */
5993                                 values[9] = NULL;
5994
5995                                 /* max_val */
5996                                 values[10] = NULL;
5997
5998                                 /* enumvals */
5999                                 values[11] = NULL;
6000                         }
6001                         break;
6002
6003                 case PGC_ENUM:
6004                         {
6005                                 /* min_val */
6006                                 values[9] = NULL;
6007
6008                                 /* max_val */
6009                                 values[10] = NULL;
6010
6011                                 /* enumvals */
6012                                 values[11] = config_enum_get_options((struct config_enum *) conf, "", "");
6013                         }
6014                         break;
6015
6016                 default:
6017                         {
6018                                 /*
6019                                  * should never get here, but in case we do, set 'em to NULL
6020                                  */
6021
6022                                 /* min_val */
6023                                 values[9] = NULL;
6024
6025                                 /* max_val */
6026                                 values[10] = NULL;
6027
6028                                 /* enumvals */
6029                                 values[11] = NULL;
6030                         }
6031                         break;
6032         }
6033 }
6034
6035 /*
6036  * Return the total number of GUC variables
6037  */
6038 int
6039 GetNumConfigOptions(void)
6040 {
6041         return num_guc_variables;
6042 }
6043
6044 /*
6045  * show_config_by_name - equiv to SHOW X command but implemented as
6046  * a function.
6047  */
6048 Datum
6049 show_config_by_name(PG_FUNCTION_ARGS)
6050 {
6051         char       *varname;
6052         char       *varval;
6053
6054         /* Get the GUC variable name */
6055         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6056
6057         /* Get the value */
6058         varval = GetConfigOptionByName(varname, NULL);
6059
6060         /* Convert to text */
6061         PG_RETURN_TEXT_P(cstring_to_text(varval));
6062 }
6063
6064 /*
6065  * show_all_settings - equiv to SHOW ALL command but implemented as
6066  * a Table Function.
6067  */
6068 #define NUM_PG_SETTINGS_ATTS    12
6069
6070 Datum
6071 show_all_settings(PG_FUNCTION_ARGS)
6072 {
6073         FuncCallContext *funcctx;
6074         TupleDesc       tupdesc;
6075         int                     call_cntr;
6076         int                     max_calls;
6077         AttInMetadata *attinmeta;
6078         MemoryContext oldcontext;
6079
6080         /* stuff done only on the first call of the function */
6081         if (SRF_IS_FIRSTCALL())
6082         {
6083                 /* create a function context for cross-call persistence */
6084                 funcctx = SRF_FIRSTCALL_INIT();
6085
6086                 /*
6087                  * switch to memory context appropriate for multiple function calls
6088                  */
6089                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6090
6091                 /*
6092                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6093                  * of the appropriate types
6094                  */
6095                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6096                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6097                                                    TEXTOID, -1, 0);
6098                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6099                                                    TEXTOID, -1, 0);
6100                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6101                                                    TEXTOID, -1, 0);
6102                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6103                                                    TEXTOID, -1, 0);
6104                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6105                                                    TEXTOID, -1, 0);
6106                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6107                                                    TEXTOID, -1, 0);
6108                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6109                                                    TEXTOID, -1, 0);
6110                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6111                                                    TEXTOID, -1, 0);
6112                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6113                                                    TEXTOID, -1, 0);
6114                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6115                                                    TEXTOID, -1, 0);
6116                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6117                                                    TEXTOID, -1, 0);
6118                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6119                                                    TEXTOID, -1, 0);
6120
6121                 /*
6122                  * Generate attribute metadata needed later to produce tuples from raw
6123                  * C strings
6124                  */
6125                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6126                 funcctx->attinmeta = attinmeta;
6127
6128                 /* total number of tuples to be returned */
6129                 funcctx->max_calls = GetNumConfigOptions();
6130
6131                 MemoryContextSwitchTo(oldcontext);
6132         }
6133
6134         /* stuff done on every call of the function */
6135         funcctx = SRF_PERCALL_SETUP();
6136
6137         call_cntr = funcctx->call_cntr;
6138         max_calls = funcctx->max_calls;
6139         attinmeta = funcctx->attinmeta;
6140
6141         if (call_cntr < max_calls)      /* do when there is more left to send */
6142         {
6143                 char       *values[NUM_PG_SETTINGS_ATTS];
6144                 bool            noshow;
6145                 HeapTuple       tuple;
6146                 Datum           result;
6147
6148                 /*
6149                  * Get the next visible GUC variable name and value
6150                  */
6151                 do
6152                 {
6153                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6154                         if (noshow)
6155                         {
6156                                 /* bump the counter and get the next config setting */
6157                                 call_cntr = ++funcctx->call_cntr;
6158
6159                                 /* make sure we haven't gone too far now */
6160                                 if (call_cntr >= max_calls)
6161                                         SRF_RETURN_DONE(funcctx);
6162                         }
6163                 } while (noshow);
6164
6165                 /* build a tuple */
6166                 tuple = BuildTupleFromCStrings(attinmeta, values);
6167
6168                 /* make the tuple into a datum */
6169                 result = HeapTupleGetDatum(tuple);
6170
6171                 SRF_RETURN_NEXT(funcctx, result);
6172         }
6173         else
6174         {
6175                 /* do when there is no more left */
6176                 SRF_RETURN_DONE(funcctx);
6177         }
6178 }
6179
6180 static char *
6181 _ShowOption(struct config_generic * record, bool use_units)
6182 {
6183         char            buffer[256];
6184         const char *val;
6185
6186         switch (record->vartype)
6187         {
6188                 case PGC_BOOL:
6189                         {
6190                                 struct config_bool *conf = (struct config_bool *) record;
6191
6192                                 if (conf->show_hook)
6193                                         val = (*conf->show_hook) ();
6194                                 else
6195                                         val = *conf->variable ? "on" : "off";
6196                         }
6197                         break;
6198
6199                 case PGC_INT:
6200                         {
6201                                 struct config_int *conf = (struct config_int *) record;
6202
6203                                 if (conf->show_hook)
6204                                         val = (*conf->show_hook) ();
6205                                 else
6206                                 {
6207                                         char            unit[4];
6208                                         int                     result = *conf->variable;
6209
6210                                         if (use_units && result > 0 && (record->flags & GUC_UNIT_MEMORY))
6211                                         {
6212                                                 switch (record->flags & GUC_UNIT_MEMORY)
6213                                                 {
6214                                                         case GUC_UNIT_BLOCKS:
6215                                                                 result *= BLCKSZ / 1024;
6216                                                                 break;
6217                                                         case GUC_UNIT_XBLOCKS:
6218                                                                 result *= XLOG_BLCKSZ / 1024;
6219                                                                 break;
6220                                                 }
6221
6222                                                 if (result % KB_PER_GB == 0)
6223                                                 {
6224                                                         result /= KB_PER_GB;
6225                                                         strcpy(unit, "GB");
6226                                                 }
6227                                                 else if (result % KB_PER_MB == 0)
6228                                                 {
6229                                                         result /= KB_PER_MB;
6230                                                         strcpy(unit, "MB");
6231                                                 }
6232                                                 else
6233                                                 {
6234                                                         strcpy(unit, "kB");
6235                                                 }
6236                                         }
6237                                         else if (use_units && result > 0 && (record->flags & GUC_UNIT_TIME))
6238                                         {
6239                                                 switch (record->flags & GUC_UNIT_TIME)
6240                                                 {
6241                                                         case GUC_UNIT_S:
6242                                                                 result *= MS_PER_S;
6243                                                                 break;
6244                                                         case GUC_UNIT_MIN:
6245                                                                 result *= MS_PER_MIN;
6246                                                                 break;
6247                                                 }
6248
6249                                                 if (result % MS_PER_D == 0)
6250                                                 {
6251                                                         result /= MS_PER_D;
6252                                                         strcpy(unit, "d");
6253                                                 }
6254                                                 else if (result % MS_PER_H == 0)
6255                                                 {
6256                                                         result /= MS_PER_H;
6257                                                         strcpy(unit, "h");
6258                                                 }
6259                                                 else if (result % MS_PER_MIN == 0)
6260                                                 {
6261                                                         result /= MS_PER_MIN;
6262                                                         strcpy(unit, "min");
6263                                                 }
6264                                                 else if (result % MS_PER_S == 0)
6265                                                 {
6266                                                         result /= MS_PER_S;
6267                                                         strcpy(unit, "s");
6268                                                 }
6269                                                 else
6270                                                 {
6271                                                         strcpy(unit, "ms");
6272                                                 }
6273                                         }
6274                                         else
6275                                                 strcpy(unit, "");
6276
6277                                         snprintf(buffer, sizeof(buffer), "%d%s",
6278                                                          (int) result, unit);
6279                                         val = buffer;
6280                                 }
6281                         }
6282                         break;
6283
6284                 case PGC_REAL:
6285                         {
6286                                 struct config_real *conf = (struct config_real *) record;
6287
6288                                 if (conf->show_hook)
6289                                         val = (*conf->show_hook) ();
6290                                 else
6291                                 {
6292                                         snprintf(buffer, sizeof(buffer), "%g",
6293                                                          *conf->variable);
6294                                         val = buffer;
6295                                 }
6296                         }
6297                         break;
6298
6299                 case PGC_STRING:
6300                         {
6301                                 struct config_string *conf = (struct config_string *) record;
6302
6303                                 if (conf->show_hook)
6304                                         val = (*conf->show_hook) ();
6305                                 else if (*conf->variable && **conf->variable)
6306                                         val = *conf->variable;
6307                                 else
6308                                         val = "";
6309                         }
6310                         break;
6311
6312                 case PGC_ENUM:
6313                         {
6314                                 struct config_enum *conf = (struct config_enum *) record;
6315
6316                                 if(conf->show_hook)
6317                                         val = (*conf->show_hook) ();
6318                                 else
6319                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6320                         }
6321                         break;
6322
6323                 default:
6324                         /* just to keep compiler quiet */
6325                         val = "???";
6326                         break;
6327         }
6328
6329         return pstrdup(val);
6330 }
6331
6332
6333 /*
6334  * Attempt (badly) to detect if a proposed new GUC setting is the same
6335  * as the current value.
6336  *
6337  * XXX this does not really work because it doesn't account for the
6338  * effects of canonicalization of string values by assign_hooks.
6339  */
6340 static bool
6341 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6342 {
6343         /* newvalue == NULL isn't supported */
6344         Assert(newvalue != NULL);
6345
6346         switch (record->vartype)
6347         {
6348                 case PGC_BOOL:
6349                         {
6350                                 struct config_bool *conf = (struct config_bool *) record;
6351                                 bool            newval;
6352
6353                                 return parse_bool(newvalue, &newval)
6354                                         && *conf->variable == newval;
6355                         }
6356                 case PGC_INT:
6357                         {
6358                                 struct config_int *conf = (struct config_int *) record;
6359                                 int                     newval;
6360
6361                                 return parse_int(newvalue, &newval, record->flags, NULL)
6362                                         && *conf->variable == newval;
6363                         }
6364                 case PGC_REAL:
6365                         {
6366                                 struct config_real *conf = (struct config_real *) record;
6367                                 double          newval;
6368
6369                                 return parse_real(newvalue, &newval)
6370                                         && *conf->variable == newval;
6371                         }
6372                 case PGC_STRING:
6373                         {
6374                                 struct config_string *conf = (struct config_string *) record;
6375
6376                                 return *conf->variable != NULL &&
6377                                         strcmp(*conf->variable, newvalue) == 0;
6378                         }
6379
6380                 case PGC_ENUM:
6381                         {
6382                                 struct config_enum *conf = (struct config_enum *) record;
6383                                 int                     newval;
6384
6385                                 return config_enum_lookup_by_name(conf, newvalue, &newval)
6386                                         && *conf->variable == newval;
6387                         }
6388         }
6389
6390         return false;
6391 }
6392
6393
6394 #ifdef EXEC_BACKEND
6395
6396 /*
6397  *      This routine dumps out all non-default GUC options into a binary
6398  *      file that is read by all exec'ed backends.  The format is:
6399  *
6400  *              variable name, string, null terminated
6401  *              variable value, string, null terminated
6402  *              variable source, integer
6403  */
6404 void
6405 write_nondefault_variables(GucContext context)
6406 {
6407         int                     i;
6408         int                     elevel;
6409         FILE       *fp;
6410
6411         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6412
6413         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6414
6415         /*
6416          * Open file
6417          */
6418         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6419         if (!fp)
6420         {
6421                 ereport(elevel,
6422                                 (errcode_for_file_access(),
6423                                  errmsg("could not write to file \"%s\": %m",
6424                                                 CONFIG_EXEC_PARAMS_NEW)));
6425                 return;
6426         }
6427
6428         for (i = 0; i < num_guc_variables; i++)
6429         {
6430                 struct config_generic *gconf = guc_variables[i];
6431
6432                 if (gconf->source != PGC_S_DEFAULT)
6433                 {
6434                         fprintf(fp, "%s", gconf->name);
6435                         fputc(0, fp);
6436
6437                         switch (gconf->vartype)
6438                         {
6439                                 case PGC_BOOL:
6440                                         {
6441                                                 struct config_bool *conf = (struct config_bool *) gconf;
6442
6443                                                 if (*conf->variable == 0)
6444                                                         fprintf(fp, "false");
6445                                                 else
6446                                                         fprintf(fp, "true");
6447                                         }
6448                                         break;
6449
6450                                 case PGC_INT:
6451                                         {
6452                                                 struct config_int *conf = (struct config_int *) gconf;
6453
6454                                                 fprintf(fp, "%d", *conf->variable);
6455                                         }
6456                                         break;
6457
6458                                 case PGC_REAL:
6459                                         {
6460                                                 struct config_real *conf = (struct config_real *) gconf;
6461
6462                                                 /* Could lose precision here? */
6463                                                 fprintf(fp, "%f", *conf->variable);
6464                                         }
6465                                         break;
6466
6467                                 case PGC_STRING:
6468                                         {
6469                                                 struct config_string *conf = (struct config_string *) gconf;
6470
6471                                                 fprintf(fp, "%s", *conf->variable);
6472                                         }
6473                                         break;
6474
6475                                 case PGC_ENUM:
6476                                         {
6477                                                 struct config_enum *conf = (struct config_enum *) gconf;
6478
6479                                                 fprintf(fp, "%s", config_enum_lookup_by_value(conf, *conf->variable));
6480                                         }
6481                                         break;
6482                         }
6483
6484                         fputc(0, fp);
6485
6486                         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6487                 }
6488         }
6489
6490         if (FreeFile(fp))
6491         {
6492                 ereport(elevel,
6493                                 (errcode_for_file_access(),
6494                                  errmsg("could not write to file \"%s\": %m",
6495                                                 CONFIG_EXEC_PARAMS_NEW)));
6496                 return;
6497         }
6498
6499         /*
6500          * Put new file in place.  This could delay on Win32, but we don't hold
6501          * any exclusive locks.
6502          */
6503         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6504 }
6505
6506
6507 /*
6508  *      Read string, including null byte from file
6509  *
6510  *      Return NULL on EOF and nothing read
6511  */
6512 static char *
6513 read_string_with_null(FILE *fp)
6514 {
6515         int                     i = 0,
6516                                 ch,
6517                                 maxlen = 256;
6518         char       *str = NULL;
6519
6520         do
6521         {
6522                 if ((ch = fgetc(fp)) == EOF)
6523                 {
6524                         if (i == 0)
6525                                 return NULL;
6526                         else
6527                                 elog(FATAL, "invalid format of exec config params file");
6528                 }
6529                 if (i == 0)
6530                         str = guc_malloc(FATAL, maxlen);
6531                 else if (i == maxlen)
6532                         str = guc_realloc(FATAL, str, maxlen *= 2);
6533                 str[i++] = ch;
6534         } while (ch != 0);
6535
6536         return str;
6537 }
6538
6539
6540 /*
6541  *      This routine loads a previous postmaster dump of its non-default
6542  *      settings.
6543  */
6544 void
6545 read_nondefault_variables(void)
6546 {
6547         FILE       *fp;
6548         char       *varname,
6549                            *varvalue;
6550         int                     varsource;
6551
6552         /*
6553          * Open file
6554          */
6555         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6556         if (!fp)
6557         {
6558                 /* File not found is fine */
6559                 if (errno != ENOENT)
6560                         ereport(FATAL,
6561                                         (errcode_for_file_access(),
6562                                          errmsg("could not read from file \"%s\": %m",
6563                                                         CONFIG_EXEC_PARAMS)));
6564                 return;
6565         }
6566
6567         for (;;)
6568         {
6569                 struct config_generic *record;
6570
6571                 if ((varname = read_string_with_null(fp)) == NULL)
6572                         break;
6573
6574                 if ((record = find_option(varname, true, FATAL)) == NULL)
6575                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6576                 if ((varvalue = read_string_with_null(fp)) == NULL)
6577                         elog(FATAL, "invalid format of exec config params file");
6578                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6579                         elog(FATAL, "invalid format of exec config params file");
6580
6581                 (void) set_config_option(varname, varvalue, record->context,
6582                                                                  varsource, GUC_ACTION_SET, true);
6583                 free(varname);
6584                 free(varvalue);
6585         }
6586
6587         FreeFile(fp);
6588 }
6589 #endif   /* EXEC_BACKEND */
6590
6591
6592 /*
6593  * A little "long argument" simulation, although not quite GNU
6594  * compliant. Takes a string of the form "some-option=some value" and
6595  * returns name = "some_option" and value = "some value" in malloc'ed
6596  * storage. Note that '-' is converted to '_' in the option name. If
6597  * there is no '=' in the input string then value will be NULL.
6598  */
6599 void
6600 ParseLongOption(const char *string, char **name, char **value)
6601 {
6602         size_t          equal_pos;
6603         char       *cp;
6604
6605         AssertArg(string);
6606         AssertArg(name);
6607         AssertArg(value);
6608
6609         equal_pos = strcspn(string, "=");
6610
6611         if (string[equal_pos] == '=')
6612         {
6613                 *name = guc_malloc(FATAL, equal_pos + 1);
6614                 strlcpy(*name, string, equal_pos + 1);
6615
6616                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6617         }
6618         else
6619         {
6620                 /* no equal sign in string */
6621                 *name = guc_strdup(FATAL, string);
6622                 *value = NULL;
6623         }
6624
6625         for (cp = *name; *cp; cp++)
6626                 if (*cp == '-')
6627                         *cp = '_';
6628 }
6629
6630
6631 /*
6632  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6633  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6634  *
6635  * The array parameter must be an array of TEXT (it must not be NULL).
6636  */
6637 void
6638 ProcessGUCArray(ArrayType *array,
6639                                 GucContext context, GucSource source, GucAction action)
6640 {
6641         int                     i;
6642
6643         Assert(array != NULL);
6644         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6645         Assert(ARR_NDIM(array) == 1);
6646         Assert(ARR_LBOUND(array)[0] == 1);
6647
6648         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6649         {
6650                 Datum           d;
6651                 bool            isnull;
6652                 char       *s;
6653                 char       *name;
6654                 char       *value;
6655
6656                 d = array_ref(array, 1, &i,
6657                                           -1 /* varlenarray */ ,
6658                                           -1 /* TEXT's typlen */ ,
6659                                           false /* TEXT's typbyval */ ,
6660                                           'i' /* TEXT's typalign */ ,
6661                                           &isnull);
6662
6663                 if (isnull)
6664                         continue;
6665
6666                 s = TextDatumGetCString(d);
6667
6668                 ParseLongOption(s, &name, &value);
6669                 if (!value)
6670                 {
6671                         ereport(WARNING,
6672                                         (errcode(ERRCODE_SYNTAX_ERROR),
6673                                          errmsg("could not parse setting for parameter \"%s\"",
6674                                                         name)));
6675                         free(name);
6676                         continue;
6677                 }
6678
6679                 (void) set_config_option(name, value, context, source, action, true);
6680
6681                 free(name);
6682                 if (value)
6683                         free(value);
6684         }
6685 }
6686
6687
6688 /*
6689  * Add an entry to an option array.  The array parameter may be NULL
6690  * to indicate the current table entry is NULL.
6691  */
6692 ArrayType *
6693 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
6694 {
6695         const char *varname;
6696         Datum           datum;
6697         char       *newval;
6698         ArrayType  *a;
6699
6700         Assert(name);
6701         Assert(value);
6702
6703         /* test if the option is valid */
6704         set_config_option(name, value,
6705                                           superuser() ? PGC_SUSET : PGC_USERSET,
6706                                           PGC_S_TEST, GUC_ACTION_SET, false);
6707
6708         /* convert name to canonical spelling, so we can use plain strcmp */
6709         (void) GetConfigOptionByName(name, &varname);
6710         name = varname;
6711
6712         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
6713         sprintf(newval, "%s=%s", name, value);
6714         datum = CStringGetTextDatum(newval);
6715
6716         if (array)
6717         {
6718                 int                     index;
6719                 bool            isnull;
6720                 int                     i;
6721
6722                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
6723                 Assert(ARR_NDIM(array) == 1);
6724                 Assert(ARR_LBOUND(array)[0] == 1);
6725
6726                 index = ARR_DIMS(array)[0] + 1; /* add after end */
6727
6728                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6729                 {
6730                         Datum           d;
6731                         char       *current;
6732
6733                         d = array_ref(array, 1, &i,
6734                                                   -1 /* varlenarray */ ,
6735                                                   -1 /* TEXT's typlen */ ,
6736                                                   false /* TEXT's typbyval */ ,
6737                                                   'i' /* TEXT's typalign */ ,
6738                                                   &isnull);
6739                         if (isnull)
6740                                 continue;
6741                         current = TextDatumGetCString(d);
6742                         if (strncmp(current, newval, strlen(name) + 1) == 0)
6743                         {
6744                                 index = i;
6745                                 break;
6746                         }
6747                 }
6748
6749                 a = array_set(array, 1, &index,
6750                                           datum,
6751                                           false,
6752                                           -1 /* varlena array */ ,
6753                                           -1 /* TEXT's typlen */ ,
6754                                           false /* TEXT's typbyval */ ,
6755                                           'i' /* TEXT's typalign */ );
6756         }
6757         else
6758                 a = construct_array(&datum, 1,
6759                                                         TEXTOID,
6760                                                         -1, false, 'i');
6761
6762         return a;
6763 }
6764
6765
6766 /*
6767  * Delete an entry from an option array.  The array parameter may be NULL
6768  * to indicate the current table entry is NULL.  Also, if the return value
6769  * is NULL then a null should be stored.
6770  */
6771 ArrayType *
6772 GUCArrayDelete(ArrayType *array, const char *name)
6773 {
6774         const char *varname;
6775         ArrayType  *newarray;
6776         int                     i;
6777         int                     index;
6778
6779         Assert(name);
6780
6781         /* test if the option is valid */
6782         set_config_option(name, NULL,
6783                                           superuser() ? PGC_SUSET : PGC_USERSET,
6784                                           PGC_S_TEST, GUC_ACTION_SET, false);
6785
6786         /* convert name to canonical spelling, so we can use plain strcmp */
6787         (void) GetConfigOptionByName(name, &varname);
6788         name = varname;
6789
6790         /* if array is currently null, then surely nothing to delete */
6791         if (!array)
6792                 return NULL;
6793
6794         newarray = NULL;
6795         index = 1;
6796
6797         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6798         {
6799                 Datum           d;
6800                 char       *val;
6801                 bool            isnull;
6802
6803                 d = array_ref(array, 1, &i,
6804                                           -1 /* varlenarray */ ,
6805                                           -1 /* TEXT's typlen */ ,
6806                                           false /* TEXT's typbyval */ ,
6807                                           'i' /* TEXT's typalign */ ,
6808                                           &isnull);
6809                 if (isnull)
6810                         continue;
6811                 val = TextDatumGetCString(d);
6812
6813                 /* ignore entry if it's what we want to delete */
6814                 if (strncmp(val, name, strlen(name)) == 0
6815                         && val[strlen(name)] == '=')
6816                         continue;
6817
6818                 /* else add it to the output array */
6819                 if (newarray)
6820                 {
6821                         newarray = array_set(newarray, 1, &index,
6822                                                                  d,
6823                                                                  false,
6824                                                                  -1 /* varlenarray */ ,
6825                                                                  -1 /* TEXT's typlen */ ,
6826                                                                  false /* TEXT's typbyval */ ,
6827                                                                  'i' /* TEXT's typalign */ );
6828                 }
6829                 else
6830                         newarray = construct_array(&d, 1,
6831                                                                            TEXTOID,
6832                                                                            -1, false, 'i');
6833
6834                 index++;
6835         }
6836
6837         return newarray;
6838 }
6839
6840
6841 /*
6842  * assign_hook and show_hook subroutines
6843  */
6844
6845 static const char *
6846 assign_log_destination(const char *value, bool doit, GucSource source)
6847 {
6848         char       *rawstring;
6849         List       *elemlist;
6850         ListCell   *l;
6851         int                     newlogdest = 0;
6852
6853         /* Need a modifiable copy of string */
6854         rawstring = pstrdup(value);
6855
6856         /* Parse string into list of identifiers */
6857         if (!SplitIdentifierString(rawstring, ',', &elemlist))
6858         {
6859                 /* syntax error in list */
6860                 pfree(rawstring);
6861                 list_free(elemlist);
6862                 ereport(GUC_complaint_elevel(source),
6863                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6864                         errmsg("invalid list syntax for parameter \"log_destination\"")));
6865                 return NULL;
6866         }
6867
6868         foreach(l, elemlist)
6869         {
6870                 char       *tok = (char *) lfirst(l);
6871
6872                 if (pg_strcasecmp(tok, "stderr") == 0)
6873                         newlogdest |= LOG_DESTINATION_STDERR;
6874                 else if (pg_strcasecmp(tok, "csvlog") == 0)
6875                         newlogdest |= LOG_DESTINATION_CSVLOG;
6876 #ifdef HAVE_SYSLOG
6877                 else if (pg_strcasecmp(tok, "syslog") == 0)
6878                         newlogdest |= LOG_DESTINATION_SYSLOG;
6879 #endif
6880 #ifdef WIN32
6881                 else if (pg_strcasecmp(tok, "eventlog") == 0)
6882                         newlogdest |= LOG_DESTINATION_EVENTLOG;
6883 #endif
6884                 else
6885                 {
6886                         ereport(GUC_complaint_elevel(source),
6887                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
6888                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
6889                                                  tok)));
6890                         pfree(rawstring);
6891                         list_free(elemlist);
6892                         return NULL;
6893                 }
6894         }
6895
6896         if (doit)
6897                 Log_destination = newlogdest;
6898
6899         pfree(rawstring);
6900         list_free(elemlist);
6901
6902         return value;
6903 }
6904
6905 #ifdef HAVE_SYSLOG
6906
6907 static bool
6908 assign_syslog_facility(int newval, bool doit, GucSource source)
6909 {
6910         if (doit)
6911                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
6912                                                           newval);
6913
6914         return true;
6915 }
6916
6917 static const char *
6918 assign_syslog_ident(const char *ident, bool doit, GucSource source)
6919 {
6920         if (doit)
6921                 set_syslog_parameters(ident, syslog_facility);
6922
6923         return ident;
6924 }
6925 #endif   /* HAVE_SYSLOG */
6926
6927
6928 static bool
6929 assign_session_replication_role(int newval, bool doit, GucSource source)
6930 {
6931         /*
6932          * Must flush the plan cache when changing replication role; but don't
6933          * flush unnecessarily.
6934          */
6935         if (doit && SessionReplicationRole != newval)
6936         {
6937                 ResetPlanCache();
6938         }
6939
6940         return true;
6941 }
6942
6943 static const char *
6944 show_num_temp_buffers(void)
6945 {
6946         /*
6947          * We show the GUC var until local buffers have been initialized, and
6948          * NLocBuffer afterwards.
6949          */
6950         static char nbuf[32];
6951
6952         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
6953         return nbuf;
6954 }
6955
6956 static bool
6957 assign_phony_autocommit(bool newval, bool doit, GucSource source)
6958 {
6959         if (!newval)
6960         {
6961                 ereport(GUC_complaint_elevel(source),
6962                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
6963                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
6964                 return false;
6965         }
6966         return true;
6967 }
6968
6969 static const char *
6970 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
6971 {
6972         /*
6973          * Check syntax. newval must be a comma separated list of identifiers.
6974          * Whitespace is allowed but removed from the result.
6975          */
6976         bool            hasSpaceAfterToken = false;
6977         const char *cp = newval;
6978         int                     symLen = 0;
6979         char            c;
6980         StringInfoData buf;
6981
6982         initStringInfo(&buf);
6983         while ((c = *cp++) != '\0')
6984         {
6985                 if (isspace((unsigned char) c))
6986                 {
6987                         if (symLen > 0)
6988                                 hasSpaceAfterToken = true;
6989                         continue;
6990                 }
6991
6992                 if (c == ',')
6993                 {
6994                         if (symLen > 0)         /* terminate identifier */
6995                         {
6996                                 appendStringInfoChar(&buf, ',');
6997                                 symLen = 0;
6998                         }
6999                         hasSpaceAfterToken = false;
7000                         continue;
7001                 }
7002
7003                 if (hasSpaceAfterToken || !isalnum((unsigned char) c))
7004                 {
7005                         /*
7006                          * Syntax error due to token following space after token or non
7007                          * alpha numeric character
7008                          */
7009                         pfree(buf.data);
7010                         return NULL;
7011                 }
7012                 appendStringInfoChar(&buf, c);
7013                 symLen++;
7014         }
7015
7016         /* Remove stray ',' at end */
7017         if (symLen == 0 && buf.len > 0)
7018                 buf.data[--buf.len] = '\0';
7019
7020         /* GUC wants the result malloc'd */
7021         newval = guc_strdup(LOG, buf.data);
7022
7023         pfree(buf.data);
7024         return newval;
7025 }
7026
7027 static bool
7028 assign_debug_assertions(bool newval, bool doit, GucSource source)
7029 {
7030 #ifndef USE_ASSERT_CHECKING
7031         if (newval)
7032         {
7033                 ereport(GUC_complaint_elevel(source),
7034                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7035                            errmsg("assertion checking is not supported by this build")));
7036                 return false;
7037         }
7038 #endif
7039         return true;
7040 }
7041
7042 static bool
7043 assign_ssl(bool newval, bool doit, GucSource source)
7044 {
7045 #ifndef USE_SSL
7046         if (newval)
7047         {
7048                 ereport(GUC_complaint_elevel(source),
7049                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7050                                  errmsg("SSL is not supported by this build")));
7051                 return false;
7052         }
7053 #endif
7054         return true;
7055 }
7056
7057 static bool
7058 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7059 {
7060         if (newval && log_statement_stats)
7061         {
7062                 ereport(GUC_complaint_elevel(source),
7063                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7064                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7065                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7066                 if (source != PGC_S_OVERRIDE)
7067                         return false;
7068         }
7069         return true;
7070 }
7071
7072 static bool
7073 assign_log_stats(bool newval, bool doit, GucSource source)
7074 {
7075         if (newval &&
7076                 (log_parser_stats || log_planner_stats || log_executor_stats))
7077         {
7078                 ereport(GUC_complaint_elevel(source),
7079                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7080                                  errmsg("cannot enable \"log_statement_stats\" when "
7081                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7082                                                 "or \"log_executor_stats\" is true")));
7083                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7084                 if (source != PGC_S_OVERRIDE)
7085                         return false;
7086         }
7087         return true;
7088 }
7089
7090 static bool
7091 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7092 {
7093         /* Can't go to r/w mode inside a r/o transaction */
7094         if (newval == false && XactReadOnly && IsSubTransaction())
7095         {
7096                 ereport(GUC_complaint_elevel(source),
7097                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7098                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7099                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7100                 if (source != PGC_S_OVERRIDE)
7101                         return false;
7102         }
7103         return true;
7104 }
7105
7106 static const char *
7107 assign_canonical_path(const char *newval, bool doit, GucSource source)
7108 {
7109         if (doit)
7110         {
7111                 char       *canon_val = guc_strdup(ERROR, newval);
7112
7113                 canonicalize_path(canon_val);
7114                 return canon_val;
7115         }
7116         else
7117                 return newval;
7118 }
7119
7120 static const char *
7121 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7122 {
7123         /*
7124          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7125          * When we see this we just do nothing.  If this value isn't overridden
7126          * from the config file then pg_timezone_abbrev_initialize() will
7127          * eventually replace it with "Default".  This hack has two purposes: to
7128          * avoid wasting cycles loading values that might soon be overridden from
7129          * the config file, and to avoid trying to read the timezone abbrev files
7130          * during InitializeGUCOptions().  The latter doesn't work in an
7131          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7132          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7133          * delay initializing TimeZone ... if we have any more, we should try to
7134          * clean up and centralize this mechanism ...)
7135          */
7136         if (strcmp(newval, "UNKNOWN") == 0)
7137         {
7138                 return newval;
7139         }
7140
7141         /* Loading abbrev file is expensive, so only do it when value changes */
7142         if (timezone_abbreviations_string == NULL ||
7143                 strcmp(timezone_abbreviations_string, newval) != 0)
7144         {
7145                 int                     elevel;
7146
7147                 /*
7148                  * If reading config file, only the postmaster should bleat loudly
7149                  * about problems.      Otherwise, it's just this one process doing it,
7150                  * and we use WARNING message level.
7151                  */
7152                 if (source == PGC_S_FILE)
7153                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7154                 else
7155                         elevel = WARNING;
7156                 if (!load_tzoffsets(newval, doit, elevel))
7157                         return NULL;
7158         }
7159         return newval;
7160 }
7161
7162 /*
7163  * pg_timezone_abbrev_initialize --- set default value if not done already
7164  *
7165  * This is called after initial loading of postgresql.conf.  If no
7166  * timezone_abbreviations setting was found therein, select default.
7167  */
7168 void
7169 pg_timezone_abbrev_initialize(void)
7170 {
7171         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7172         {
7173                 SetConfigOption("timezone_abbreviations", "Default",
7174                                                 PGC_POSTMASTER, PGC_S_ARGV);
7175         }
7176 }
7177
7178 static const char *
7179 show_archive_command(void)
7180 {
7181         if (XLogArchiveMode)
7182                 return XLogArchiveCommand;
7183         else
7184                 return "(disabled)";
7185 }
7186
7187 static bool
7188 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7189 {
7190         if (doit)
7191                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7192
7193         return true;
7194 }
7195
7196 static const char *
7197 show_tcp_keepalives_idle(void)
7198 {
7199         static char nbuf[16];
7200
7201         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7202         return nbuf;
7203 }
7204
7205 static bool
7206 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7207 {
7208         if (doit)
7209                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7210
7211         return true;
7212 }
7213
7214 static const char *
7215 show_tcp_keepalives_interval(void)
7216 {
7217         static char nbuf[16];
7218
7219         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7220         return nbuf;
7221 }
7222
7223 static bool
7224 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7225 {
7226         if (doit)
7227                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7228
7229         return true;
7230 }
7231
7232 static const char *
7233 show_tcp_keepalives_count(void)
7234 {
7235         static char nbuf[16];
7236
7237         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7238         return nbuf;
7239 }
7240
7241 static bool
7242 assign_maxconnections(int newval, bool doit, GucSource source)
7243 {
7244         if (newval + autovacuum_max_workers > INT_MAX / 4)
7245                 return false;
7246
7247         if (doit)
7248                 MaxBackends = newval + autovacuum_max_workers;
7249
7250         return true;
7251 }
7252
7253 static bool
7254 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7255 {
7256         if (newval + MaxConnections > INT_MAX / 4)
7257                 return false;
7258
7259         if (doit)
7260                 MaxBackends = newval + MaxConnections;
7261
7262         return true;
7263 }
7264
7265 #include "guc-file.c"