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

   1 /*--------------------------------------------------------------------
   2  * guc.c
   3  *
   4  * Support for grand unified configuration scheme, including SET
   5  * command, configuration file, and command line options.
   6  * See src/backend/utils/misc/README for more information.
   7  *
   8  *
   9  * Copyright (c) 2000-2009, PostgreSQL Global Development Group
  10  * Written by Peter Eisentraut <peter_e@gmx.net>.
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.494 2009/01/16 13:27:24 heikki Exp $
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <math.h>
  22 #include <limits.h>
  23 #include <unistd.h>
  24 #include <sys/stat.h>
  25 #ifdef HAVE_SYSLOG
  26 #include <syslog.h>
  27 #endif
  28
  29 #include "access/gin.h"
  30 #include "access/transam.h"
  31 #include "access/twophase.h"
  32 #include "access/xact.h"
  33 #include "catalog/namespace.h"
  34 #include "commands/async.h"
  35 #include "commands/prepare.h"
  36 #include "commands/vacuum.h"
  37 #include "commands/variable.h"
  38 #include "commands/trigger.h"
  39 #include "funcapi.h"
  40 #include "libpq/auth.h"
  41 #include "libpq/pqformat.h"
  42 #include "miscadmin.h"
  43 #include "optimizer/cost.h"
  44 #include "optimizer/geqo.h"
  45 #include "optimizer/paths.h"
  46 #include "optimizer/planmain.h"
  47 #include "parser/gramparse.h"
  48 #include "parser/parse_expr.h"
  49 #include "parser/parse_relation.h"
  50 #include "parser/parse_type.h"
  51 #include "parser/scansup.h"
  52 #include "pgstat.h"
  53 #include "postmaster/autovacuum.h"
  54 #include "postmaster/bgwriter.h"
  55 #include "postmaster/postmaster.h"
  56 #include "postmaster/syslogger.h"
  57 #include "postmaster/walwriter.h"
  58 #include "regex/regex.h"
  59 #include "storage/bufmgr.h"
  60 #include "storage/fd.h"
  61 #include "tcop/tcopprot.h"
  62 #include "tsearch/ts_cache.h"
  63 #include "utils/builtins.h"
  64 #include "utils/guc_tables.h"
  65 #include "utils/memutils.h"
  66 #include "utils/pg_locale.h"
  67 #include "utils/plancache.h"
  68 #include "utils/portal.h"
  69 #include "utils/ps_status.h"
  70 #include "utils/tzparser.h"
  71 #include "utils/xml.h"
  72
  73 #ifndef PG_KRB_SRVTAB
  74 #define PG_KRB_SRVTAB ""
  75 #endif
  76 #ifndef PG_KRB_SRVNAM
  77 #define PG_KRB_SRVNAM ""
  78 #endif
  79
  80 #define CONFIG_FILENAME "postgresql.conf"
  81 #define HBA_FILENAME    "pg_hba.conf"
  82 #define IDENT_FILENAME  "pg_ident.conf"
  83
  84 #ifdef EXEC_BACKEND
  85 #define CONFIG_EXEC_PARAMS "global/config_exec_params"
  86 #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
  87 #endif
  88
  89 /* upper limit for GUC variables measured in kilobytes of memory */
  90 #if SIZEOF_SIZE_T > 4
  91 #define MAX_KILOBYTES   INT_MAX
  92 #else
  93 #define MAX_KILOBYTES   (INT_MAX / 1024)
  94 #endif
  95
  96 #define KB_PER_MB (1024)
  97 #define KB_PER_GB (1024*1024)
  98
  99 #define MS_PER_S 1000
 100 #define S_PER_MIN 60
 101 #define MS_PER_MIN (1000 * 60)
 102 #define MIN_PER_H 60
 103 #define S_PER_H (60 * 60)
 104 #define MS_PER_H (1000 * 60 * 60)
 105 #define MIN_PER_D (60 * 24)
 106 #define S_PER_D (60 * 60 * 24)
 107 #define MS_PER_D (1000 * 60 * 60 * 24)
 108
 109 /* XXX these should appear in other modules' header files */
 110 extern bool Log_disconnections;
 111 extern int      CommitDelay;
 112 extern int      CommitSiblings;
 113 extern char *default_tablespace;
 114 extern char *temp_tablespaces;
 115 extern bool synchronize_seqscans;
 116 extern bool fullPageWrites;
 117
 118 #ifdef TRACE_SORT
 119 extern bool trace_sort;
 120 #endif
 121 #ifdef TRACE_SYNCSCAN
 122 extern bool trace_syncscan;
 123 #endif
 124 #ifdef DEBUG_BOUNDED_SORT
 125 extern bool optimize_bounded_sort;
 126 #endif
 127
 128 #ifdef USE_SSL
 129 extern char *SSLCipherSuites;
 130 #endif
 131
 132 static void set_config_sourcefile(const char *name, char *sourcefile,
 133                                           int sourceline);
 134
 135 static const char *assign_log_destination(const char *value,
 136                                            bool doit, GucSource source);
 137
 138 #ifdef HAVE_SYSLOG
 139 static int      syslog_facility = LOG_LOCAL0;
 140
 141 static bool assign_syslog_facility(int newval,
 142                                     bool doit, GucSource source);
 143 static const char *assign_syslog_ident(const char *ident,
 144                                         bool doit, GucSource source);
 145 #endif
 146
 147 static bool assign_session_replication_role(int newval, bool doit,
 148                                                                 GucSource source);
 149 static const char *show_num_temp_buffers(void);
 150 static bool assign_phony_autocommit(bool newval, bool doit, GucSource source);
 151 static const char *assign_custom_variable_classes(const char *newval, bool doit,
 152                                                            GucSource source);
 153 static bool assign_debug_assertions(bool newval, bool doit, GucSource source);
 154 static bool assign_ssl(bool newval, bool doit, GucSource source);
 155 static bool assign_stage_log_stats(bool newval, bool doit, GucSource source);
 156 static bool assign_log_stats(bool newval, bool doit, GucSource source);
 157 static bool assign_transaction_read_only(bool newval, bool doit, GucSource source);
 158 static const char *assign_canonical_path(const char *newval, bool doit, GucSource source);
 159 static const char *assign_timezone_abbreviations(const char *newval, bool doit, GucSource source);
 160 static const char *show_archive_command(void);
 161 static bool assign_tcp_keepalives_idle(int newval, bool doit, GucSource source);
 162 static bool assign_tcp_keepalives_interval(int newval, bool doit, GucSource source);
 163 static bool assign_tcp_keepalives_count(int newval, bool doit, GucSource source);
 164 static const char *show_tcp_keepalives_idle(void);
 165 static const char *show_tcp_keepalives_interval(void);
 166 static const char *show_tcp_keepalives_count(void);
 167 static bool assign_maxconnections(int newval, bool doit, GucSource source);
 168 static bool assign_autovacuum_max_workers(int newval, bool doit, GucSource source);
 169 static bool assign_effective_io_concurrency(int newval, bool doit, GucSource source);
 170 static const char *assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source);
 171
 172 static char *config_enum_get_options(struct config_enum *record,
 173                                                                          const char *prefix, const char *suffix,
 174                                                                          const char *separator);
 175
 176
 177 /*
 178  * Options for enum values defined in this module.
 179  *
 180  * NOTE! Option values may not contain double quotes!
 181  */
 182
 183 /*
 184  * We have different sets for client and server message level options because
 185  * they sort slightly different (see "log" level)
 186  */
 187 static const struct config_enum_entry client_message_level_options[] = {
 188         {"debug", DEBUG2, true},
 189         {"debug5", DEBUG5, false},
 190         {"debug4", DEBUG4, false},
 191         {"debug3", DEBUG3, false},
 192         {"debug2", DEBUG2, false},
 193         {"debug1", DEBUG1, false},
 194         {"log", LOG, false},
 195         {"info", INFO, true},
 196         {"notice", NOTICE, false},
 197         {"warning", WARNING, false},
 198         {"error", ERROR, false},
 199         {"fatal", FATAL, true},
 200         {"panic", PANIC, true},
 201         {NULL, 0, false}
 202 };
 203
 204 static const struct config_enum_entry server_message_level_options[] = {
 205         {"debug", DEBUG2, true},
 206         {"debug5", DEBUG5, false},
 207         {"debug4", DEBUG4, false},
 208         {"debug3", DEBUG3, false},
 209         {"debug2", DEBUG2, false},
 210         {"debug1", DEBUG1, false},
 211         {"info", INFO, false},
 212         {"notice", NOTICE, false},
 213         {"warning", WARNING, false},
 214         {"error", ERROR, false},
 215         {"log", LOG, false},
 216         {"fatal", FATAL, false},
 217         {"panic", PANIC, false},
 218         {NULL, 0, false}
 219 };
 220
 221 static const struct config_enum_entry intervalstyle_options[] = {
 222         {"postgres", INTSTYLE_POSTGRES, false},
 223         {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
 224         {"sql_standard", INTSTYLE_SQL_STANDARD, false},
 225         {"iso_8601", INTSTYLE_ISO_8601, false},
 226         {NULL, 0, false}
 227 };
 228
 229 static const struct config_enum_entry log_error_verbosity_options[] = {
 230         {"terse", PGERROR_TERSE, false},
 231         {"default", PGERROR_DEFAULT, false},
 232         {"verbose", PGERROR_VERBOSE, false},
 233         {NULL, 0, false}
 234 };
 235
 236 static const struct config_enum_entry log_statement_options[] = {
 237         {"none", LOGSTMT_NONE, false},
 238         {"ddl", LOGSTMT_DDL, false},
 239         {"mod", LOGSTMT_MOD, false},
 240         {"all", LOGSTMT_ALL, false},
 241         {NULL, 0, false}
 242 };
 243
 244 static const struct config_enum_entry regex_flavor_options[] = {
 245     {"advanced", REG_ADVANCED, false},
 246     {"extended", REG_EXTENDED, false},
 247     {"basic", REG_BASIC, false},
 248     {NULL, 0, false}
 249 };
 250
 251 static const struct config_enum_entry isolation_level_options[] = {
 252         {"serializable", XACT_SERIALIZABLE, false},
 253         {"repeatable read", XACT_REPEATABLE_READ, false},
 254         {"read committed", XACT_READ_COMMITTED, false},
 255         {"read uncommitted", XACT_READ_UNCOMMITTED, false},
 256         {NULL, 0}
 257 };
 258
 259 static const struct config_enum_entry session_replication_role_options[] = {
 260         {"origin", SESSION_REPLICATION_ROLE_ORIGIN, false},
 261         {"replica", SESSION_REPLICATION_ROLE_REPLICA, false},
 262         {"local", SESSION_REPLICATION_ROLE_LOCAL, false},
 263         {NULL, 0, false}
 264 };
 265
 266 #ifdef HAVE_SYSLOG
 267 static const struct config_enum_entry syslog_facility_options[] = {
 268         {"local0", LOG_LOCAL0, false},
 269         {"local1", LOG_LOCAL1, false},
 270         {"local2", LOG_LOCAL2, false},
 271         {"local3", LOG_LOCAL3, false},
 272         {"local4", LOG_LOCAL4, false},
 273         {"local5", LOG_LOCAL5, false},
 274         {"local6", LOG_LOCAL6, false},
 275         {"local7", LOG_LOCAL7, false},
 276         {NULL, 0}
 277 };
 278 #endif
 279
 280 static const struct config_enum_entry track_function_options[] = {
 281         {"none", TRACK_FUNC_OFF, false},
 282         {"pl", TRACK_FUNC_PL, false},
 283         {"all", TRACK_FUNC_ALL, false},
 284         {NULL, 0, false}
 285 };
 286
 287 static const struct config_enum_entry xmlbinary_options[] = {
 288         {"base64", XMLBINARY_BASE64, false},
 289         {"hex", XMLBINARY_HEX, false},
 290         {NULL, 0, false}
 291 };
 292
 293 static const struct config_enum_entry xmloption_options[] = {
 294         {"content", XMLOPTION_CONTENT, false},
 295         {"document", XMLOPTION_DOCUMENT, false},
 296         {NULL, 0, false}
 297 };
 298
 299 /*
 300  * Although only "on", "off", and "safe_encoding" are documented, we
 301  * accept all the likely variants of "on" and "off".
 302  */
 303 static const struct config_enum_entry backslash_quote_options[] = {
 304         {"safe_encoding", BACKSLASH_QUOTE_SAFE_ENCODING, false},
 305         {"on", BACKSLASH_QUOTE_ON, false},
 306         {"off", BACKSLASH_QUOTE_OFF, false},
 307         {"true", BACKSLASH_QUOTE_ON, true},
 308         {"false", BACKSLASH_QUOTE_OFF, true},
 309         {"yes", BACKSLASH_QUOTE_ON, true},
 310         {"no", BACKSLASH_QUOTE_OFF, true},
 311         {"1", BACKSLASH_QUOTE_ON, true},
 312         {"0", BACKSLASH_QUOTE_OFF, true},
 313         {NULL, 0, false}
 314 };
 315
 316 /*
 317  * Although only "on", "off", and "partition" are documented, we
 318  * accept all the likely variants of "on" and "off".
 319  */
 320 static const struct config_enum_entry constraint_exclusion_options[] = {
 321         {"partition", CONSTRAINT_EXCLUSION_PARTITION, false},
 322         {"on", CONSTRAINT_EXCLUSION_ON, false},
 323         {"off", CONSTRAINT_EXCLUSION_OFF, false},
 324         {"true", CONSTRAINT_EXCLUSION_ON, true},
 325         {"false", CONSTRAINT_EXCLUSION_OFF, true},
 326         {"yes", CONSTRAINT_EXCLUSION_ON, true},
 327         {"no", CONSTRAINT_EXCLUSION_OFF, true},
 328         {"1", CONSTRAINT_EXCLUSION_ON, true},
 329         {"0", CONSTRAINT_EXCLUSION_OFF, true},
 330         {NULL, 0, false}
 331 };
 332
 333 /*
 334  * Options for enum values stored in other modules
 335  */
 336 extern const struct config_enum_entry sync_method_options[];
 337
 338 /*
 339  * GUC option variables that are exported from this module
 340  */
 341 #ifdef USE_ASSERT_CHECKING
 342 bool            assert_enabled = true;
 343 #else
 344 bool            assert_enabled = false;
 345 #endif
 346 bool            log_duration = false;
 347 bool            Debug_print_plan = false;
 348 bool            Debug_print_parse = false;
 349 bool            Debug_print_rewritten = false;
 350 bool            Debug_pretty_print = true;
 351
 352 bool            log_parser_stats = false;
 353 bool            log_planner_stats = false;
 354 bool            log_executor_stats = false;
 355 bool            log_statement_stats = false;            /* this is sort of all three
 356                                                                                                  * above together */
 357 bool            log_btree_build_stats = false;
 358
 359 bool            check_function_bodies = true;
 360 bool            default_with_oids = false;
 361 bool            SQL_inheritance = true;
 362
 363 bool            Password_encryption = true;
 364
 365 int                     log_min_error_statement = ERROR;
 366 int                     log_min_messages = WARNING;
 367 int                     client_min_messages = NOTICE;
 368 int                     log_min_duration_statement = -1;
 369 int                     log_temp_files = -1;
 370
 371 int                     num_temp_buffers = 1000;
 372
 373 char       *ConfigFileName;
 374 char       *HbaFileName;
 375 char       *IdentFileName;
 376 char       *external_pid_file;
 377
 378 char       *pgstat_temp_directory;
 379
 380 int                     tcp_keepalives_idle;
 381 int                     tcp_keepalives_interval;
 382 int                     tcp_keepalives_count;
 383
 384 /*
 385  * These variables are all dummies that don't do anything, except in some
 386  * cases provide the value for SHOW to display.  The real state is elsewhere
 387  * and is kept in sync by assign_hooks.
 388  */
 389 static char *log_destination_string;
 390
 391 #ifdef HAVE_SYSLOG
 392 static char *syslog_ident_str;
 393 #endif
 394 static bool phony_autocommit;
 395 static bool session_auth_is_superuser;
 396 static double phony_random_seed;
 397 static char *client_encoding_string;
 398 static char *datestyle_string;
 399 static char *locale_collate;
 400 static char *locale_ctype;
 401 static char *server_encoding_string;
 402 static char *server_version_string;
 403 static int      server_version_num;
 404 static char *timezone_string;
 405 static char *log_timezone_string;
 406 static char *timezone_abbreviations_string;
 407 static char *XactIsoLevel_string;
 408 static char *data_directory;
 409 static char *custom_variable_classes;
 410 static int      max_function_args;
 411 static int      max_index_keys;
 412 static int      max_identifier_length;
 413 static int      block_size;
 414 static int      segment_size;
 415 static int      wal_block_size;
 416 static int      wal_segment_size;
 417 static bool integer_datetimes;
 418 static int      effective_io_concurrency;
 419
 420 /* should be static, but commands/variable.c needs to get at these */
 421 char       *role_string;
 422 char       *session_authorization_string;
 423
 424
 425 /*
 426  * Displayable names for context types (enum GucContext)
 427  *
 428  * Note: these strings are deliberately not localized.
 429  */
 430 const char *const GucContext_Names[] =
 431 {
 432          /* PGC_INTERNAL */ "internal",
 433          /* PGC_POSTMASTER */ "postmaster",
 434          /* PGC_SIGHUP */ "sighup",
 435          /* PGC_BACKEND */ "backend",
 436          /* PGC_SUSET */ "superuser",
 437          /* PGC_USERSET */ "user"
 438 };
 439
 440 /*
 441  * Displayable names for source types (enum GucSource)
 442  *
 443  * Note: these strings are deliberately not localized.
 444  */
 445 const char *const GucSource_Names[] =
 446 {
 447          /* PGC_S_DEFAULT */ "default",
 448          /* PGC_S_ENV_VAR */ "environment variable",
 449          /* PGC_S_FILE */ "configuration file",
 450          /* PGC_S_ARGV */ "command line",
 451          /* PGC_S_DATABASE */ "database",
 452          /* PGC_S_USER */ "user",
 453          /* PGC_S_CLIENT */ "client",
 454          /* PGC_S_OVERRIDE */ "override",
 455          /* PGC_S_INTERACTIVE */ "interactive",
 456          /* PGC_S_TEST */ "test",
 457          /* PGC_S_SESSION */ "session"
 458 };
 459
 460 /*
 461  * Displayable names for the groupings defined in enum config_group
 462  */
 463 const char *const config_group_names[] =
 464 {
 465         /* UNGROUPED */
 466         gettext_noop("Ungrouped"),
 467         /* FILE_LOCATIONS */
 468         gettext_noop("File Locations"),
 469         /* CONN_AUTH */
 470         gettext_noop("Connections and Authentication"),
 471         /* CONN_AUTH_SETTINGS */
 472         gettext_noop("Connections and Authentication / Connection Settings"),
 473         /* CONN_AUTH_SECURITY */
 474         gettext_noop("Connections and Authentication / Security and Authentication"),
 475         /* RESOURCES */
 476         gettext_noop("Resource Usage"),
 477         /* RESOURCES_MEM */
 478         gettext_noop("Resource Usage / Memory"),
 479         /* RESOURCES_KERNEL */
 480         gettext_noop("Resource Usage / Kernel Resources"),
 481         /* WAL */
 482         gettext_noop("Write-Ahead Log"),
 483         /* WAL_SETTINGS */
 484         gettext_noop("Write-Ahead Log / Settings"),
 485         /* WAL_CHECKPOINTS */
 486         gettext_noop("Write-Ahead Log / Checkpoints"),
 487         /* QUERY_TUNING */
 488         gettext_noop("Query Tuning"),
 489         /* QUERY_TUNING_METHOD */
 490         gettext_noop("Query Tuning / Planner Method Configuration"),
 491         /* QUERY_TUNING_COST */
 492         gettext_noop("Query Tuning / Planner Cost Constants"),
 493         /* QUERY_TUNING_GEQO */
 494         gettext_noop("Query Tuning / Genetic Query Optimizer"),
 495         /* QUERY_TUNING_OTHER */
 496         gettext_noop("Query Tuning / Other Planner Options"),
 497         /* LOGGING */
 498         gettext_noop("Reporting and Logging"),
 499         /* LOGGING_WHERE */
 500         gettext_noop("Reporting and Logging / Where to Log"),
 501         /* LOGGING_WHEN */
 502         gettext_noop("Reporting and Logging / When to Log"),
 503         /* LOGGING_WHAT */
 504         gettext_noop("Reporting and Logging / What to Log"),
 505         /* STATS */
 506         gettext_noop("Statistics"),
 507         /* STATS_MONITORING */
 508         gettext_noop("Statistics / Monitoring"),
 509         /* STATS_COLLECTOR */
 510         gettext_noop("Statistics / Query and Index Statistics Collector"),
 511         /* AUTOVACUUM */
 512         gettext_noop("Autovacuum"),
 513         /* CLIENT_CONN */
 514         gettext_noop("Client Connection Defaults"),
 515         /* CLIENT_CONN_STATEMENT */
 516         gettext_noop("Client Connection Defaults / Statement Behavior"),
 517         /* CLIENT_CONN_LOCALE */
 518         gettext_noop("Client Connection Defaults / Locale and Formatting"),
 519         /* CLIENT_CONN_OTHER */
 520         gettext_noop("Client Connection Defaults / Other Defaults"),
 521         /* LOCK_MANAGEMENT */
 522         gettext_noop("Lock Management"),
 523         /* COMPAT_OPTIONS */
 524         gettext_noop("Version and Platform Compatibility"),
 525         /* COMPAT_OPTIONS_PREVIOUS */
 526         gettext_noop("Version and Platform Compatibility / Previous PostgreSQL Versions"),
 527         /* COMPAT_OPTIONS_CLIENT */
 528         gettext_noop("Version and Platform Compatibility / Other Platforms and Clients"),
 529         /* PRESET_OPTIONS */
 530         gettext_noop("Preset Options"),
 531         /* CUSTOM_OPTIONS */
 532         gettext_noop("Customized Options"),
 533         /* DEVELOPER_OPTIONS */
 534         gettext_noop("Developer Options"),
 535         /* help_config wants this array to be null-terminated */
 536         NULL
 537 };
 538
 539 /*
 540  * Displayable names for GUC variable types (enum config_type)
 541  *
 542  * Note: these strings are deliberately not localized.
 543  */
 544 const char *const config_type_names[] =
 545 {
 546          /* PGC_BOOL */ "bool",
 547          /* PGC_INT */ "integer",
 548          /* PGC_REAL */ "real",
 549          /* PGC_STRING */ "string",
 550          /* PGC_ENUM */ "enum"
 551 };
 552
 553
 554 /*
 555  * Contents of GUC tables
 556  *
 557  * See src/backend/utils/misc/README for design notes.
 558  *
 559  * TO ADD AN OPTION:
 560  *
 561  * 1. Declare a global variable of type bool, int, double, or char*
 562  *        and make use of it.
 563  *
 564  * 2. Decide at what times it's safe to set the option. See guc.h for
 565  *        details.
 566  *
 567  * 3. Decide on a name, a default value, upper and lower bounds (if
 568  *        applicable), etc.
 569  *
 570  * 4. Add a record below.
 571  *
 572  * 5. Add it to src/backend/utils/misc/postgresql.conf.sample, if
 573  *        appropriate.
 574  *
 575  * 6. Don't forget to document the option (at least in config.sgml).
 576  *
 577  * 7. If it's a new GUC_LIST option you must edit pg_dumpall.c to ensure
 578  *        it is not single quoted at dump time.
 579  */
 580
 581
 582 /******** option records follow ********/
 583
 584 static struct config_bool ConfigureNamesBool[] =
 585 {
 586         {
 587                 {"enable_seqscan", PGC_USERSET, QUERY_TUNING_METHOD,
 588                         gettext_noop("Enables the planner's use of sequential-scan plans."),
 589                         NULL
 590                 },
 591                 &enable_seqscan,
 592                 true, NULL, NULL
 593         },
 594         {
 595                 {"enable_indexscan", PGC_USERSET, QUERY_TUNING_METHOD,
 596                         gettext_noop("Enables the planner's use of index-scan plans."),
 597                         NULL
 598                 },
 599                 &enable_indexscan,
 600                 true, NULL, NULL
 601         },
 602         {
 603                 {"enable_bitmapscan", PGC_USERSET, QUERY_TUNING_METHOD,
 604                         gettext_noop("Enables the planner's use of bitmap-scan plans."),
 605                         NULL
 606                 },
 607                 &enable_bitmapscan,
 608                 true, NULL, NULL
 609         },
 610         {
 611                 {"enable_tidscan", PGC_USERSET, QUERY_TUNING_METHOD,
 612                         gettext_noop("Enables the planner's use of TID scan plans."),
 613                         NULL
 614                 },
 615                 &enable_tidscan,
 616                 true, NULL, NULL
 617         },
 618         {
 619                 {"enable_sort", PGC_USERSET, QUERY_TUNING_METHOD,
 620                         gettext_noop("Enables the planner's use of explicit sort steps."),
 621                         NULL
 622                 },
 623                 &enable_sort,
 624                 true, NULL, NULL
 625         },
 626         {
 627                 {"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
 628                         gettext_noop("Enables the planner's use of hashed aggregation plans."),
 629                         NULL
 630                 },
 631                 &enable_hashagg,
 632                 true, NULL, NULL
 633         },
 634         {
 635                 {"enable_nestloop", PGC_USERSET, QUERY_TUNING_METHOD,
 636                         gettext_noop("Enables the planner's use of nested-loop join plans."),
 637                         NULL
 638                 },
 639                 &enable_nestloop,
 640                 true, NULL, NULL
 641         },
 642         {
 643                 {"enable_mergejoin", PGC_USERSET, QUERY_TUNING_METHOD,
 644                         gettext_noop("Enables the planner's use of merge join plans."),
 645                         NULL
 646                 },
 647                 &enable_mergejoin,
 648                 true, NULL, NULL
 649         },
 650         {
 651                 {"enable_hashjoin", PGC_USERSET, QUERY_TUNING_METHOD,
 652                         gettext_noop("Enables the planner's use of hash join plans."),
 653                         NULL
 654                 },
 655                 &enable_hashjoin,
 656                 true, NULL, NULL
 657         },
 658         {
 659                 {"geqo", PGC_USERSET, QUERY_TUNING_GEQO,
 660                         gettext_noop("Enables genetic query optimization."),
 661                         gettext_noop("This algorithm attempts to do planning without "
 662                                                  "exhaustive searching.")
 663                 },
 664                 &enable_geqo,
 665                 true, NULL, NULL
 666         },
 667         {
 668                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
 669                 {"is_superuser", PGC_INTERNAL, UNGROUPED,
 670                         gettext_noop("Shows whether the current user is a superuser."),
 671                         NULL,
 672                         GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
 673                 },
 674                 &session_auth_is_superuser,
 675                 false, NULL, NULL
 676         },
 677         {
 678                 {"ssl", PGC_POSTMASTER, CONN_AUTH_SECURITY,
 679                         gettext_noop("Enables SSL connections."),
 680                         NULL
 681                 },
 682                 &EnableSSL,
 683                 false, assign_ssl, NULL
 684         },
 685         {
 686                 {"fsync", PGC_SIGHUP, WAL_SETTINGS,
 687                         gettext_noop("Forces synchronization of updates to disk."),
 688                         gettext_noop("The server will use the fsync() system call in several places to make "
 689                         "sure that updates are physically written to disk. This insures "
 690                                                  "that a database cluster will recover to a consistent state after "
 691                                                  "an operating system or hardware crash.")
 692                 },
 693                 &enableFsync,
 694                 true, NULL, NULL
 695         },
 696         {
 697                 {"synchronous_commit", PGC_USERSET, WAL_SETTINGS,
 698                         gettext_noop("Sets immediate fsync at commit."),
 699                         NULL
 700                 },
 701                 &XactSyncCommit,
 702                 true, NULL, NULL
 703         },
 704         {
 705                 {"zero_damaged_pages", PGC_SUSET, DEVELOPER_OPTIONS,
 706                         gettext_noop("Continues processing past damaged page headers."),
 707                         gettext_noop("Detection of a damaged page header normally causes PostgreSQL to "
 708                                 "report an error, aborting the current transaction. Setting "
 709                                                  "zero_damaged_pages to true causes the system to instead report a "
 710                                                  "warning, zero out the damaged page, and continue processing. This "
 711                                                  "behavior will destroy data, namely all the rows on the damaged page."),
 712                         GUC_NOT_IN_SAMPLE
 713                 },
 714                 &zero_damaged_pages,
 715                 false, NULL, NULL
 716         },
 717         {
 718                 {"full_page_writes", PGC_SIGHUP, WAL_SETTINGS,
 719                         gettext_noop("Writes full pages to WAL when first modified after a checkpoint."),
 720                         gettext_noop("A page write in process during an operating system crash might be "
 721                                                  "only partially written to disk.  During recovery, the row changes "
 722                           "stored in WAL are not enough to recover.  This option writes "
 723                                                  "pages when first modified after a checkpoint to WAL so full recovery "
 724                                                  "is possible.")
 725                 },
 726                 &fullPageWrites,
 727                 true, NULL, NULL
 728         },
 729         {
 730                 {"silent_mode", PGC_POSTMASTER, LOGGING_WHEN,
 731                         gettext_noop("Runs the server silently."),
 732                         gettext_noop("If this parameter is set, the server will automatically run in the "
 733                                  "background and any controlling terminals are dissociated.")
 734                 },
 735                 &SilentMode,
 736                 false, NULL, NULL
 737         },
 738         {
 739                 {"log_checkpoints", PGC_SIGHUP, LOGGING_WHAT,
 740                         gettext_noop("Logs each checkpoint."),
 741                         NULL
 742                 },
 743                 &log_checkpoints,
 744                 false, NULL, NULL
 745         },
 746         {
 747                 {"log_connections", PGC_BACKEND, LOGGING_WHAT,
 748                         gettext_noop("Logs each successful connection."),
 749                         NULL
 750                 },
 751                 &Log_connections,
 752                 false, NULL, NULL
 753         },
 754         {
 755                 {"log_disconnections", PGC_BACKEND, LOGGING_WHAT,
 756                         gettext_noop("Logs end of a session, including duration."),
 757                         NULL
 758                 },
 759                 &Log_disconnections,
 760                 false, NULL, NULL
 761         },
 762         {
 763                 {"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
 764                         gettext_noop("Turns on various assertion checks."),
 765                         gettext_noop("This is a debugging aid."),
 766                         GUC_NOT_IN_SAMPLE
 767                 },
 768                 &assert_enabled,
 769 #ifdef USE_ASSERT_CHECKING
 770                 true,
 771 #else
 772                 false,
 773 #endif
 774                 assign_debug_assertions, NULL
 775         },
 776         {
 777                 /* currently undocumented, so don't show in SHOW ALL */
 778                 {"exit_on_error", PGC_USERSET, UNGROUPED,
 779                         gettext_noop("No description available."),
 780                         NULL,
 781                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
 782                 },
 783                 &ExitOnAnyError,
 784                 false, NULL, NULL
 785         },
 786         {
 787                 {"log_duration", PGC_SUSET, LOGGING_WHAT,
 788                         gettext_noop("Logs the duration of each completed SQL statement."),
 789                         NULL
 790                 },
 791                 &log_duration,
 792                 false, NULL, NULL
 793         },
 794         {
 795                 {"debug_print_parse", PGC_USERSET, LOGGING_WHAT,
 796                         gettext_noop("Logs each query's parse tree."),
 797                         NULL
 798                 },
 799                 &Debug_print_parse,
 800                 false, NULL, NULL
 801         },
 802         {
 803                 {"debug_print_rewritten", PGC_USERSET, LOGGING_WHAT,
 804                         gettext_noop("Logs each query's rewritten parse tree."),
 805                         NULL
 806                 },
 807                 &Debug_print_rewritten,
 808                 false, NULL, NULL
 809         },
 810         {
 811                 {"debug_print_plan", PGC_USERSET, LOGGING_WHAT,
 812                         gettext_noop("Logs each query's execution plan."),
 813                         NULL
 814                 },
 815                 &Debug_print_plan,
 816                 false, NULL, NULL
 817         },
 818         {
 819                 {"debug_pretty_print", PGC_USERSET, LOGGING_WHAT,
 820                         gettext_noop("Indents parse and plan tree displays."),
 821                         NULL
 822                 },
 823                 &Debug_pretty_print,
 824                 true, NULL, NULL
 825         },
 826         {
 827                 {"log_parser_stats", PGC_SUSET, STATS_MONITORING,
 828                         gettext_noop("Writes parser performance statistics to the server log."),
 829                         NULL
 830                 },
 831                 &log_parser_stats,
 832                 false, assign_stage_log_stats, NULL
 833         },
 834         {
 835                 {"log_planner_stats", PGC_SUSET, STATS_MONITORING,
 836                         gettext_noop("Writes planner performance statistics to the server log."),
 837                         NULL
 838                 },
 839                 &log_planner_stats,
 840                 false, assign_stage_log_stats, NULL
 841         },
 842         {
 843                 {"log_executor_stats", PGC_SUSET, STATS_MONITORING,
 844                         gettext_noop("Writes executor performance statistics to the server log."),
 845                         NULL
 846                 },
 847                 &log_executor_stats,
 848                 false, assign_stage_log_stats, NULL
 849         },
 850         {
 851                 {"log_statement_stats", PGC_SUSET, STATS_MONITORING,
 852                         gettext_noop("Writes cumulative performance statistics to the server log."),
 853                         NULL
 854                 },
 855                 &log_statement_stats,
 856                 false, assign_log_stats, NULL
 857         },
 858 #ifdef BTREE_BUILD_STATS
 859         {
 860                 {"log_btree_build_stats", PGC_SUSET, DEVELOPER_OPTIONS,
 861                         gettext_noop("No description available."),
 862                         NULL,
 863                         GUC_NOT_IN_SAMPLE
 864                 },
 865                 &log_btree_build_stats,
 866                 false, NULL, NULL
 867         },
 868 #endif
 869
 870         {
 871                 {"track_activities", PGC_SUSET, STATS_COLLECTOR,
 872                         gettext_noop("Collects information about executing commands."),
 873                         gettext_noop("Enables the collection of information on the currently "
 874                                                  "executing command of each session, along with "
 875                                                  "the time at which that command began execution.")
 876                 },
 877                 &pgstat_track_activities,
 878                 true, NULL, NULL
 879         },
 880         {
 881                 {"track_counts", PGC_SUSET, STATS_COLLECTOR,
 882                         gettext_noop("Collects statistics on database activity."),
 883                         NULL
 884                 },
 885                 &pgstat_track_counts,
 886                 true, NULL, NULL
 887         },
 888
 889         {
 890                 {"update_process_title", PGC_SUSET, STATS_COLLECTOR,
 891                         gettext_noop("Updates the process title to show the active SQL command."),
 892                         gettext_noop("Enables updating of the process title every time a new SQL command is received by the server.")
 893                 },
 894                 &update_process_title,
 895                 true, NULL, NULL
 896         },
 897
 898         {
 899                 {"autovacuum", PGC_SIGHUP, AUTOVACUUM,
 900                         gettext_noop("Starts the autovacuum subprocess."),
 901                         NULL
 902                 },
 903                 &autovacuum_start_daemon,
 904                 true, NULL, NULL
 905         },
 906
 907         {
 908                 {"trace_notify", PGC_USERSET, DEVELOPER_OPTIONS,
 909                         gettext_noop("Generates debugging output for LISTEN and NOTIFY."),
 910                         NULL,
 911                         GUC_NOT_IN_SAMPLE
 912                 },
 913                 &Trace_notify,
 914                 false, NULL, NULL
 915         },
 916
 917 #ifdef LOCK_DEBUG
 918         {
 919                 {"trace_locks", PGC_SUSET, DEVELOPER_OPTIONS,
 920                         gettext_noop("No description available."),
 921                         NULL,
 922                         GUC_NOT_IN_SAMPLE
 923                 },
 924                 &Trace_locks,
 925                 false, NULL, NULL
 926         },
 927         {
 928                 {"trace_userlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 929                         gettext_noop("No description available."),
 930                         NULL,
 931                         GUC_NOT_IN_SAMPLE
 932                 },
 933                 &Trace_userlocks,
 934                 false, NULL, NULL
 935         },
 936         {
 937                 {"trace_lwlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 938                         gettext_noop("No description available."),
 939                         NULL,
 940                         GUC_NOT_IN_SAMPLE
 941                 },
 942                 &Trace_lwlocks,
 943                 false, NULL, NULL
 944         },
 945         {
 946                 {"debug_deadlocks", PGC_SUSET, DEVELOPER_OPTIONS,
 947                         gettext_noop("No description available."),
 948                         NULL,
 949                         GUC_NOT_IN_SAMPLE
 950                 },
 951                 &Debug_deadlocks,
 952                 false, NULL, NULL
 953         },
 954 #endif
 955
 956         {
 957                 {"log_lock_waits", PGC_SUSET, LOGGING_WHAT,
 958                         gettext_noop("Logs long lock waits."),
 959                         NULL
 960                 },
 961                 &log_lock_waits,
 962                 false, NULL, NULL
 963         },
 964
 965         {
 966                 {"log_hostname", PGC_SIGHUP, LOGGING_WHAT,
 967                         gettext_noop("Logs the host name in the connection logs."),
 968                         gettext_noop("By default, connection logs only show the IP address "
 969                                                  "of the connecting host. If you want them to show the host name you "
 970                           "can turn this on, but depending on your host name resolution "
 971                            "setup it might impose a non-negligible performance penalty.")
 972                 },
 973                 &log_hostname,
 974                 false, NULL, NULL
 975         },
 976         {
 977                 {"sql_inheritance", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
 978                         gettext_noop("Causes subtables to be included by default in various commands."),
 979                         NULL
 980                 },
 981                 &SQL_inheritance,
 982                 true, NULL, NULL
 983         },
 984         {
 985                 {"password_encryption", PGC_USERSET, CONN_AUTH_SECURITY,
 986                         gettext_noop("Encrypt passwords."),
 987                         gettext_noop("When a password is specified in CREATE USER or "
 988                            "ALTER USER without writing either ENCRYPTED or UNENCRYPTED, "
 989                                                  "this parameter determines whether the password is to be encrypted.")
 990                 },
 991                 &Password_encryption,
 992                 true, NULL, NULL
 993         },
 994         {
 995                 {"transform_null_equals", PGC_USERSET, COMPAT_OPTIONS_CLIENT,
 996                         gettext_noop("Treats \"expr=NULL\" as \"expr IS NULL\"."),
 997                         gettext_noop("When turned on, expressions of the form expr = NULL "
 998                            "(or NULL = expr) are treated as expr IS NULL, that is, they "
 999                                 "return true if expr evaluates to the null value, and false "
1000                            "otherwise. The correct behavior of expr = NULL is to always "
1001                                                  "return null (unknown).")
1002                 },
1003                 &Transform_null_equals,
1004                 false, NULL, NULL
1005         },
1006         {
1007                 {"db_user_namespace", PGC_SIGHUP, CONN_AUTH_SECURITY,
1008                         gettext_noop("Enables per-database user names."),
1009                         NULL
1010                 },
1011                 &Db_user_namespace,
1012                 false, NULL, NULL
1013         },
1014         {
1015                 /* only here for backwards compatibility */
1016                 {"autocommit", PGC_USERSET, CLIENT_CONN_STATEMENT,
1017                         gettext_noop("This parameter doesn't do anything."),
1018                         gettext_noop("It's just here so that we won't choke on SET AUTOCOMMIT TO ON from 7.3-vintage clients."),
1019                         GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
1020                 },
1021                 &phony_autocommit,
1022                 true, assign_phony_autocommit, NULL
1023         },
1024         {
1025                 {"default_transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1026                         gettext_noop("Sets the default read-only status of new transactions."),
1027                         NULL
1028                 },
1029                 &DefaultXactReadOnly,
1030                 false, NULL, NULL
1031         },
1032         {
1033                 {"transaction_read_only", PGC_USERSET, CLIENT_CONN_STATEMENT,
1034                         gettext_noop("Sets the current transaction's read-only status."),
1035                         NULL,
1036                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1037                 },
1038                 &XactReadOnly,
1039                 false, assign_transaction_read_only, NULL
1040         },
1041         {
1042                 {"add_missing_from", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1043                         gettext_noop("Automatically adds missing table references to FROM clauses."),
1044                         NULL
1045                 },
1046                 &add_missing_from,
1047                 false, NULL, NULL
1048         },
1049         {
1050                 {"check_function_bodies", PGC_USERSET, CLIENT_CONN_STATEMENT,
1051                         gettext_noop("Check function bodies during CREATE FUNCTION."),
1052                         NULL
1053                 },
1054                 &check_function_bodies,
1055                 true, NULL, NULL
1056         },
1057         {
1058                 {"array_nulls", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1059                         gettext_noop("Enable input of NULL elements in arrays."),
1060                         gettext_noop("When turned on, unquoted NULL in an array input "
1061                                                  "value means a null value; "
1062                                                  "otherwise it is taken literally.")
1063                 },
1064                 &Array_nulls,
1065                 true, NULL, NULL
1066         },
1067         {
1068                 {"default_with_oids", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1069                         gettext_noop("Create new tables with OIDs by default."),
1070                         NULL
1071                 },
1072                 &default_with_oids,
1073                 false, NULL, NULL
1074         },
1075         {
1076                 {"logging_collector", PGC_POSTMASTER, LOGGING_WHERE,
1077                         gettext_noop("Start a subprocess to capture stderr output and/or csvlogs into log files."),
1078                         NULL
1079                 },
1080                 &Logging_collector,
1081                 false, NULL, NULL
1082         },
1083         {
1084                 {"log_truncate_on_rotation", PGC_SIGHUP, LOGGING_WHERE,
1085                         gettext_noop("Truncate existing log files of same name during log rotation."),
1086                         NULL
1087                 },
1088                 &Log_truncate_on_rotation,
1089                 false, NULL, NULL
1090         },
1091
1092 #ifdef TRACE_SORT
1093         {
1094                 {"trace_sort", PGC_USERSET, DEVELOPER_OPTIONS,
1095                         gettext_noop("Emit information about resource usage in sorting."),
1096                         NULL,
1097                         GUC_NOT_IN_SAMPLE
1098                 },
1099                 &trace_sort,
1100                 false, NULL, NULL
1101         },
1102 #endif
1103
1104 #ifdef TRACE_SYNCSCAN
1105         /* this is undocumented because not exposed in a standard build */
1106         {
1107                 {"trace_syncscan", PGC_USERSET, DEVELOPER_OPTIONS,
1108                         gettext_noop("Generate debugging output for synchronized scanning."),
1109                         NULL,
1110                         GUC_NOT_IN_SAMPLE
1111                 },
1112                 &trace_syncscan,
1113                 false, NULL, NULL
1114         },
1115 #endif
1116
1117 #ifdef DEBUG_BOUNDED_SORT
1118         /* this is undocumented because not exposed in a standard build */
1119         {
1120                 {
1121                         "optimize_bounded_sort", PGC_USERSET, QUERY_TUNING_METHOD,
1122                         gettext_noop("Enable bounded sorting using heap sort."),
1123                         NULL,
1124                         GUC_NOT_IN_SAMPLE
1125                 },
1126                 &optimize_bounded_sort,
1127                 true, NULL, NULL
1128         },
1129 #endif
1130
1131 #ifdef WAL_DEBUG
1132         {
1133                 {"wal_debug", PGC_SUSET, DEVELOPER_OPTIONS,
1134                         gettext_noop("Emit WAL-related debugging output."),
1135                         NULL,
1136                         GUC_NOT_IN_SAMPLE
1137                 },
1138                 &XLOG_DEBUG,
1139                 false, NULL, NULL
1140         },
1141 #endif
1142
1143         {
1144                 {"integer_datetimes", PGC_INTERNAL, PRESET_OPTIONS,
1145                         gettext_noop("Datetimes are integer based."),
1146                         NULL,
1147                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1148                 },
1149                 &integer_datetimes,
1150 #ifdef HAVE_INT64_TIMESTAMP
1151                 true, NULL, NULL
1152 #else
1153                 false, NULL, NULL
1154 #endif
1155         },
1156
1157         {
1158                 {"krb_caseins_users", PGC_SIGHUP, CONN_AUTH_SECURITY,
1159                         gettext_noop("Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive."),
1160                         NULL
1161                 },
1162                 &pg_krb_caseins_users,
1163                 false, NULL, NULL
1164         },
1165
1166         {
1167                 {"escape_string_warning", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1168                         gettext_noop("Warn about backslash escapes in ordinary string literals."),
1169                         NULL
1170                 },
1171                 &escape_string_warning,
1172                 true, NULL, NULL
1173         },
1174
1175         {
1176                 {"standard_conforming_strings", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1177                         gettext_noop("Causes '...' strings to treat backslashes literally."),
1178                         NULL,
1179                         GUC_REPORT
1180                 },
1181                 &standard_conforming_strings,
1182                 false, NULL, NULL
1183         },
1184
1185         {
1186                 {"synchronize_seqscans", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
1187                         gettext_noop("Enable synchronized sequential scans."),
1188                         NULL
1189                 },
1190                 &synchronize_seqscans,
1191                 true, NULL, NULL
1192         },
1193
1194         {
1195                 {"archive_mode", PGC_POSTMASTER, WAL_SETTINGS,
1196                         gettext_noop("Allows archiving of WAL files using archive_command."),
1197                         NULL
1198                 },
1199                 &XLogArchiveMode,
1200                 false, NULL, NULL
1201         },
1202
1203         {
1204                 {"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
1205                         gettext_noop("Allows modifications of the structure of system tables."),
1206                         NULL,
1207                         GUC_NOT_IN_SAMPLE
1208                 },
1209                 &allowSystemTableMods,
1210                 false, NULL, NULL
1211         },
1212
1213         {
1214                 {"ignore_system_indexes", PGC_BACKEND, DEVELOPER_OPTIONS,
1215                         gettext_noop("Disables reading from system indexes."),
1216                         gettext_noop("It does not prevent updating the indexes, so it is safe "
1217                                                  "to use.  The worst consequence is slowness."),
1218                         GUC_NOT_IN_SAMPLE
1219                 },
1220                 &IgnoreSystemIndexes,
1221                 false, NULL, NULL
1222         },
1223
1224         /* End-of-list marker */
1225         {
1226                 {NULL, 0, 0, NULL, NULL}, NULL, false, NULL, NULL
1227         }
1228 };
1229
1230
1231 static struct config_int ConfigureNamesInt[] =
1232 {
1233         {
1234                 {"archive_timeout", PGC_SIGHUP, WAL_SETTINGS,
1235                         gettext_noop("Forces a switch to the next xlog file if a "
1236                                                  "new file has not been started within N seconds."),
1237                         NULL,
1238                         GUC_UNIT_S
1239                 },
1240                 &XLogArchiveTimeout,
1241                 0, 0, INT_MAX, NULL, NULL
1242         },
1243         {
1244                 {"post_auth_delay", PGC_BACKEND, DEVELOPER_OPTIONS,
1245                         gettext_noop("Waits N seconds on connection startup after authentication."),
1246                         gettext_noop("This allows attaching a debugger to the process."),
1247                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1248                 },
1249                 &PostAuthDelay,
1250                 0, 0, INT_MAX, NULL, NULL
1251         },
1252         {
1253                 {"default_statistics_target", PGC_USERSET, QUERY_TUNING_OTHER,
1254                         gettext_noop("Sets the default statistics target."),
1255                         gettext_noop("This applies to table columns that have not had a "
1256                                 "column-specific target set via ALTER TABLE SET STATISTICS.")
1257                 },
1258                 &default_statistics_target,
1259                 100, 1, 10000, NULL, NULL
1260         },
1261         {
1262                 {"from_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1263                         gettext_noop("Sets the FROM-list size beyond which subqueries "
1264                                                  "are not collapsed."),
1265                         gettext_noop("The planner will merge subqueries into upper "
1266                                 "queries if the resulting FROM list would have no more than "
1267                                                  "this many items.")
1268                 },
1269                 &from_collapse_limit,
1270                 8, 1, INT_MAX, NULL, NULL
1271         },
1272         {
1273                 {"join_collapse_limit", PGC_USERSET, QUERY_TUNING_OTHER,
1274                         gettext_noop("Sets the FROM-list size beyond which JOIN "
1275                                                  "constructs are not flattened."),
1276                         gettext_noop("The planner will flatten explicit JOIN "
1277                                                  "constructs into lists of FROM items whenever a "
1278                                                  "list of no more than this many items would result.")
1279                 },
1280                 &join_collapse_limit,
1281                 8, 1, INT_MAX, NULL, NULL
1282         },
1283         {
1284                 {"geqo_threshold", PGC_USERSET, QUERY_TUNING_GEQO,
1285                         gettext_noop("Sets the threshold of FROM items beyond which GEQO is used."),
1286                         NULL
1287                 },
1288                 &geqo_threshold,
1289                 12, 2, INT_MAX, NULL, NULL
1290         },
1291         {
1292                 {"geqo_effort", PGC_USERSET, QUERY_TUNING_GEQO,
1293                         gettext_noop("GEQO: effort is used to set the default for other GEQO parameters."),
1294                         NULL
1295                 },
1296                 &Geqo_effort,
1297                 DEFAULT_GEQO_EFFORT, MIN_GEQO_EFFORT, MAX_GEQO_EFFORT, NULL, NULL
1298         },
1299         {
1300                 {"geqo_pool_size", PGC_USERSET, QUERY_TUNING_GEQO,
1301                         gettext_noop("GEQO: number of individuals in the population."),
1302                         gettext_noop("Zero selects a suitable default value.")
1303                 },
1304                 &Geqo_pool_size,
1305                 0, 0, INT_MAX, NULL, NULL
1306         },
1307         {
1308                 {"geqo_generations", PGC_USERSET, QUERY_TUNING_GEQO,
1309                         gettext_noop("GEQO: number of iterations of the algorithm."),
1310                         gettext_noop("Zero selects a suitable default value.")
1311                 },
1312                 &Geqo_generations,
1313                 0, 0, INT_MAX, NULL, NULL
1314         },
1315
1316         {
1317                 /* This is PGC_SIGHUP so all backends have the same value. */
1318                 {"deadlock_timeout", PGC_SIGHUP, LOCK_MANAGEMENT,
1319                         gettext_noop("Sets the time to wait on a lock before checking for deadlock."),
1320                         NULL,
1321                         GUC_UNIT_MS
1322                 },
1323                 &DeadlockTimeout,
1324                 1000, 1, INT_MAX / 1000, NULL, NULL
1325         },
1326
1327         /*
1328          * Note: MaxBackends is limited to INT_MAX/4 because some places compute
1329          * 4*MaxBackends without any overflow check.  This check is made in
1330          * assign_maxconnections, since MaxBackends is computed as MaxConnections
1331          * plus autovacuum_max_workers.
1332          *
1333          * Likewise we have to limit NBuffers to INT_MAX/2.
1334          */
1335         {
1336                 {"max_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1337                         gettext_noop("Sets the maximum number of concurrent connections."),
1338                         NULL
1339                 },
1340                 &MaxConnections,
1341                 100, 1, INT_MAX / 4, assign_maxconnections, NULL
1342         },
1343
1344         {
1345                 {"superuser_reserved_connections", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1346                         gettext_noop("Sets the number of connection slots reserved for superusers."),
1347                         NULL
1348                 },
1349                 &ReservedBackends,
1350                 3, 0, INT_MAX / 4, NULL, NULL
1351         },
1352
1353         {
1354                 {"shared_buffers", PGC_POSTMASTER, RESOURCES_MEM,
1355                         gettext_noop("Sets the number of shared memory buffers used by the server."),
1356                         NULL,
1357                         GUC_UNIT_BLOCKS
1358                 },
1359                 &NBuffers,
1360                 1024, 16, INT_MAX / 2, NULL, NULL
1361         },
1362
1363         {
1364                 {"temp_buffers", PGC_USERSET, RESOURCES_MEM,
1365                         gettext_noop("Sets the maximum number of temporary buffers used by each session."),
1366                         NULL,
1367                         GUC_UNIT_BLOCKS
1368                 },
1369                 &num_temp_buffers,
1370                 1024, 100, INT_MAX / 2, NULL, show_num_temp_buffers
1371         },
1372
1373         {
1374                 {"port", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1375                         gettext_noop("Sets the TCP port the server listens on."),
1376                         NULL
1377                 },
1378                 &PostPortNumber,
1379                 DEF_PGPORT, 1, 65535, NULL, NULL
1380         },
1381
1382         {
1383                 {"unix_socket_permissions", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
1384                         gettext_noop("Sets the access permissions of the Unix-domain socket."),
1385                         gettext_noop("Unix-domain sockets use the usual Unix file system "
1386                                                  "permission set. The parameter value is expected to be a numeric mode "
1387                                                  "specification in the form accepted by the chmod and umask system "
1388                                                  "calls. (To use the customary octal format the number must start with "
1389                                                  "a 0 (zero).)")
1390                 },
1391                 &Unix_socket_permissions,
1392                 0777, 0000, 0777, NULL, NULL
1393         },
1394
1395         {
1396                 {"work_mem", PGC_USERSET, RESOURCES_MEM,
1397                         gettext_noop("Sets the maximum memory to be used for query workspaces."),
1398                         gettext_noop("This much memory can be used by each internal "
1399                                                  "sort operation and hash table before switching to "
1400                                                  "temporary disk files."),
1401                         GUC_UNIT_KB
1402                 },
1403                 &work_mem,
1404                 1024, 64, MAX_KILOBYTES, NULL, NULL
1405         },
1406
1407         {
1408                 {"maintenance_work_mem", PGC_USERSET, RESOURCES_MEM,
1409                         gettext_noop("Sets the maximum memory to be used for maintenance operations."),
1410                         gettext_noop("This includes operations such as VACUUM and CREATE INDEX."),
1411                         GUC_UNIT_KB
1412                 },
1413                 &maintenance_work_mem,
1414                 16384, 1024, MAX_KILOBYTES, NULL, NULL
1415         },
1416
1417         {
1418                 {"max_stack_depth", PGC_SUSET, RESOURCES_MEM,
1419                         gettext_noop("Sets the maximum stack depth, in kilobytes."),
1420                         NULL,
1421                         GUC_UNIT_KB
1422                 },
1423                 &max_stack_depth,
1424                 100, 100, MAX_KILOBYTES, assign_max_stack_depth, NULL
1425         },
1426
1427         {
1428                 {"vacuum_cost_page_hit", PGC_USERSET, RESOURCES,
1429                         gettext_noop("Vacuum cost for a page found in the buffer cache."),
1430                         NULL
1431                 },
1432                 &VacuumCostPageHit,
1433                 1, 0, 10000, NULL, NULL
1434         },
1435
1436         {
1437                 {"vacuum_cost_page_miss", PGC_USERSET, RESOURCES,
1438                         gettext_noop("Vacuum cost for a page not found in the buffer cache."),
1439                         NULL
1440                 },
1441                 &VacuumCostPageMiss,
1442                 10, 0, 10000, NULL, NULL
1443         },
1444
1445         {
1446                 {"vacuum_cost_page_dirty", PGC_USERSET, RESOURCES,
1447                         gettext_noop("Vacuum cost for a page dirtied by vacuum."),
1448                         NULL
1449                 },
1450                 &VacuumCostPageDirty,
1451                 20, 0, 10000, NULL, NULL
1452         },
1453
1454         {
1455                 {"vacuum_cost_limit", PGC_USERSET, RESOURCES,
1456                         gettext_noop("Vacuum cost amount available before napping."),
1457                         NULL
1458                 },
1459                 &VacuumCostLimit,
1460                 200, 1, 10000, NULL, NULL
1461         },
1462
1463         {
1464                 {"vacuum_cost_delay", PGC_USERSET, RESOURCES,
1465                         gettext_noop("Vacuum cost delay in milliseconds."),
1466                         NULL,
1467                         GUC_UNIT_MS
1468                 },
1469                 &VacuumCostDelay,
1470                 0, 0, 1000, NULL, NULL
1471         },
1472
1473         {
1474                 {"autovacuum_vacuum_cost_delay", PGC_SIGHUP, AUTOVACUUM,
1475                         gettext_noop("Vacuum cost delay in milliseconds, for autovacuum."),
1476                         NULL,
1477                         GUC_UNIT_MS
1478                 },
1479                 &autovacuum_vac_cost_delay,
1480                 20, -1, 1000, NULL, NULL
1481         },
1482
1483         {
1484                 {"autovacuum_vacuum_cost_limit", PGC_SIGHUP, AUTOVACUUM,
1485                         gettext_noop("Vacuum cost amount available before napping, for autovacuum."),
1486                         NULL
1487                 },
1488                 &autovacuum_vac_cost_limit,
1489                 -1, -1, 10000, NULL, NULL
1490         },
1491
1492         {
1493                 {"max_files_per_process", PGC_POSTMASTER, RESOURCES_KERNEL,
1494                         gettext_noop("Sets the maximum number of simultaneously open files for each server process."),
1495                         NULL
1496                 },
1497                 &max_files_per_process,
1498                 1000, 25, INT_MAX, NULL, NULL
1499         },
1500
1501         {
1502                 {"max_prepared_transactions", PGC_POSTMASTER, RESOURCES,
1503                         gettext_noop("Sets the maximum number of simultaneously prepared transactions."),
1504                         NULL
1505                 },
1506                 &max_prepared_xacts,
1507                 5, 0, INT_MAX, NULL, NULL
1508         },
1509
1510 #ifdef LOCK_DEBUG
1511         {
1512                 {"trace_lock_oidmin", PGC_SUSET, DEVELOPER_OPTIONS,
1513                         gettext_noop("No description available."),
1514                         NULL,
1515                         GUC_NOT_IN_SAMPLE
1516                 },
1517                 &Trace_lock_oidmin,
1518                 FirstNormalObjectId, 0, INT_MAX, NULL, NULL
1519         },
1520         {
1521                 {"trace_lock_table", PGC_SUSET, DEVELOPER_OPTIONS,
1522                         gettext_noop("No description available."),
1523                         NULL,
1524                         GUC_NOT_IN_SAMPLE
1525                 },
1526                 &Trace_lock_table,
1527                 0, 0, INT_MAX, NULL, NULL
1528         },
1529 #endif
1530
1531         {
1532                 {"statement_timeout", PGC_USERSET, CLIENT_CONN_STATEMENT,
1533                         gettext_noop("Sets the maximum allowed duration of any statement."),
1534                         gettext_noop("A value of 0 turns off the timeout."),
1535                         GUC_UNIT_MS
1536                 },
1537                 &StatementTimeout,
1538                 0, 0, INT_MAX, NULL, NULL
1539         },
1540
1541         {
1542                 {"vacuum_freeze_min_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1543                         gettext_noop("Minimum age at which VACUUM should freeze a table row."),
1544                         NULL
1545                 },
1546                 &vacuum_freeze_min_age,
1547                 50000000, 0, 1000000000, NULL, NULL
1548         },
1549
1550         {
1551                 {"vacuum_freeze_table_age", PGC_USERSET, CLIENT_CONN_STATEMENT,
1552                         gettext_noop("Age at which VACUUM should scan whole table to freeze tuples."),
1553                         NULL
1554                 },
1555                 &vacuum_freeze_table_age,
1556                 150000000, 0, 2000000000, NULL, NULL
1557         },
1558
1559         {
1560                 {"max_locks_per_transaction", PGC_POSTMASTER, LOCK_MANAGEMENT,
1561                         gettext_noop("Sets the maximum number of locks per transaction."),
1562                         gettext_noop("The shared lock table is sized on the assumption that "
1563                           "at most max_locks_per_transaction * max_connections distinct "
1564                                                  "objects will need to be locked at any one time.")
1565                 },
1566                 &max_locks_per_xact,
1567                 64, 10, INT_MAX, NULL, NULL
1568         },
1569
1570         {
1571                 {"authentication_timeout", PGC_SIGHUP, CONN_AUTH_SECURITY,
1572                         gettext_noop("Sets the maximum allowed time to complete client authentication."),
1573                         NULL,
1574                         GUC_UNIT_S
1575                 },
1576                 &AuthenticationTimeout,
1577                 60, 1, 600, NULL, NULL
1578         },
1579
1580         {
1581                 /* Not for general use */
1582                 {"pre_auth_delay", PGC_SIGHUP, DEVELOPER_OPTIONS,
1583                         gettext_noop("Waits N seconds on connection startup before authentication."),
1584                         gettext_noop("This allows attaching a debugger to the process."),
1585                         GUC_NOT_IN_SAMPLE | GUC_UNIT_S
1586                 },
1587                 &PreAuthDelay,
1588                 0, 0, 60, NULL, NULL
1589         },
1590
1591         {
1592                 {"checkpoint_segments", PGC_SIGHUP, WAL_CHECKPOINTS,
1593                         gettext_noop("Sets the maximum distance in log segments between automatic WAL checkpoints."),
1594                         NULL
1595                 },
1596                 &CheckPointSegments,
1597                 3, 1, INT_MAX, NULL, NULL
1598         },
1599
1600         {
1601                 {"checkpoint_timeout", PGC_SIGHUP, WAL_CHECKPOINTS,
1602                         gettext_noop("Sets the maximum time between automatic WAL checkpoints."),
1603                         NULL,
1604                         GUC_UNIT_S
1605                 },
1606                 &CheckPointTimeout,
1607                 300, 30, 3600, NULL, NULL
1608         },
1609
1610         {
1611                 {"checkpoint_warning", PGC_SIGHUP, WAL_CHECKPOINTS,
1612                         gettext_noop("Enables warnings if checkpoint segments are filled more "
1613                                                  "frequently than this."),
1614                         gettext_noop("Write a message to the server log if checkpoints "
1615                         "caused by the filling of checkpoint segment files happens more "
1616                                                  "frequently than this number of seconds. Zero turns off the warning."),
1617                         GUC_UNIT_S
1618                 },
1619                 &CheckPointWarning,
1620                 30, 0, INT_MAX, NULL, NULL
1621         },
1622
1623         {
1624                 {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
1625                         gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
1626                         NULL,
1627                         GUC_UNIT_XBLOCKS
1628                 },
1629                 &XLOGbuffers,
1630                 8, 4, INT_MAX, NULL, NULL
1631         },
1632
1633         {
1634                 {"wal_writer_delay", PGC_SIGHUP, WAL_SETTINGS,
1635                         gettext_noop("WAL writer sleep time between WAL flushes."),
1636                         NULL,
1637                         GUC_UNIT_MS
1638                 },
1639                 &WalWriterDelay,
1640                 200, 1, 10000, NULL, NULL
1641         },
1642
1643         {
1644                 {"commit_delay", PGC_USERSET, WAL_SETTINGS,
1645                         gettext_noop("Sets the delay in microseconds between transaction commit and "
1646                                                  "flushing WAL to disk."),
1647                         NULL
1648                 },
1649                 &CommitDelay,
1650                 0, 0, 100000, NULL, NULL
1651         },
1652
1653         {
1654                 {"commit_siblings", PGC_USERSET, WAL_SETTINGS,
1655                         gettext_noop("Sets the minimum concurrent open transactions before performing "
1656                                                  "commit_delay."),
1657                         NULL
1658                 },
1659                 &CommitSiblings,
1660                 5, 1, 1000, NULL, NULL
1661         },
1662
1663         {
1664                 {"extra_float_digits", PGC_USERSET, CLIENT_CONN_LOCALE,
1665                         gettext_noop("Sets the number of digits displayed for floating-point values."),
1666                         gettext_noop("This affects real, double precision, and geometric data types. "
1667                          "The parameter value is added to the standard number of digits "
1668                                                  "(FLT_DIG or DBL_DIG as appropriate).")
1669                 },
1670                 &extra_float_digits,
1671                 0, -15, 2, NULL, NULL
1672         },
1673
1674         {
1675                 {"log_min_duration_statement", PGC_SUSET, LOGGING_WHEN,
1676                         gettext_noop("Sets the minimum execution time above which "
1677                                                  "statements will be logged."),
1678                         gettext_noop("Zero prints all queries. -1 turns this feature off."),
1679                         GUC_UNIT_MS
1680                 },
1681                 &log_min_duration_statement,
1682                 -1, -1, INT_MAX / 1000, NULL, NULL
1683         },
1684
1685         {
1686                 {"log_autovacuum_min_duration", PGC_SIGHUP, LOGGING_WHAT,
1687                         gettext_noop("Sets the minimum execution time above which "
1688                                                  "autovacuum actions will be logged."),
1689                         gettext_noop("Zero prints all actions. -1 turns autovacuum logging off."),
1690                         GUC_UNIT_MS
1691                 },
1692                 &Log_autovacuum_min_duration,
1693                 -1, -1, INT_MAX / 1000, NULL, NULL
1694         },
1695
1696         {
1697                 {"bgwriter_delay", PGC_SIGHUP, RESOURCES,
1698                         gettext_noop("Background writer sleep time between rounds."),
1699                         NULL,
1700                         GUC_UNIT_MS
1701                 },
1702                 &BgWriterDelay,
1703                 200, 10, 10000, NULL, NULL
1704         },
1705
1706         {
1707                 {"bgwriter_lru_maxpages", PGC_SIGHUP, RESOURCES,
1708                         gettext_noop("Background writer maximum number of LRU pages to flush per round."),
1709                         NULL
1710                 },
1711                 &bgwriter_lru_maxpages,
1712                 100, 0, 1000, NULL, NULL
1713         },
1714
1715         {
1716                 {"effective_io_concurrency", PGC_USERSET, RESOURCES,
1717                         gettext_noop("Number of simultaneous requests that can be handled efficiently by the disk subsystem."),
1718                         gettext_noop("For RAID arrays, this should be approximately the number of drive spindles in the array.")
1719                 },
1720                 &effective_io_concurrency,
1721 #ifdef USE_PREFETCH
1722                 1, 0, 1000,
1723 #else
1724                 0, 0, 0,
1725 #endif
1726                 assign_effective_io_concurrency, NULL
1727         },
1728
1729         {
1730                 {"log_rotation_age", PGC_SIGHUP, LOGGING_WHERE,
1731                         gettext_noop("Automatic log file rotation will occur after N minutes."),
1732                         NULL,
1733                         GUC_UNIT_MIN
1734                 },
1735                 &Log_RotationAge,
1736                 HOURS_PER_DAY * MINS_PER_HOUR, 0, INT_MAX / MINS_PER_HOUR, NULL, NULL
1737         },
1738
1739         {
1740                 {"log_rotation_size", PGC_SIGHUP, LOGGING_WHERE,
1741                         gettext_noop("Automatic log file rotation will occur after N kilobytes."),
1742                         NULL,
1743                         GUC_UNIT_KB
1744                 },
1745                 &Log_RotationSize,
1746                 10 * 1024, 0, INT_MAX / 1024, NULL, NULL
1747         },
1748
1749         {
1750                 {"max_function_args", PGC_INTERNAL, PRESET_OPTIONS,
1751                         gettext_noop("Shows the maximum number of function arguments."),
1752                         NULL,
1753                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1754                 },
1755                 &max_function_args,
1756                 FUNC_MAX_ARGS, FUNC_MAX_ARGS, FUNC_MAX_ARGS, NULL, NULL
1757         },
1758
1759         {
1760                 {"max_index_keys", PGC_INTERNAL, PRESET_OPTIONS,
1761                         gettext_noop("Shows the maximum number of index keys."),
1762                         NULL,
1763                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1764                 },
1765                 &max_index_keys,
1766                 INDEX_MAX_KEYS, INDEX_MAX_KEYS, INDEX_MAX_KEYS, NULL, NULL
1767         },
1768
1769         {
1770                 {"max_identifier_length", PGC_INTERNAL, PRESET_OPTIONS,
1771                         gettext_noop("Shows the maximum identifier length."),
1772                         NULL,
1773                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1774                 },
1775                 &max_identifier_length,
1776                 NAMEDATALEN - 1, NAMEDATALEN - 1, NAMEDATALEN - 1, NULL, NULL
1777         },
1778
1779         {
1780                 {"block_size", PGC_INTERNAL, PRESET_OPTIONS,
1781                         gettext_noop("Shows the size of a disk block."),
1782                         NULL,
1783                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1784                 },
1785                 &block_size,
1786                 BLCKSZ, BLCKSZ, BLCKSZ, NULL, NULL
1787         },
1788
1789         {
1790                 {"segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1791                     gettext_noop("Shows the number of pages per disk file."),
1792                     NULL,
1793                     GUC_UNIT_BLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1794                 },
1795                 &segment_size,
1796                 RELSEG_SIZE, RELSEG_SIZE, RELSEG_SIZE, NULL, NULL
1797         },
1798
1799         {
1800                 {"wal_block_size", PGC_INTERNAL, PRESET_OPTIONS,
1801                         gettext_noop("Shows the block size in the write ahead log."),
1802                         NULL,
1803                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1804                 },
1805                 &wal_block_size,
1806                 XLOG_BLCKSZ, XLOG_BLCKSZ, XLOG_BLCKSZ, NULL, NULL
1807         },
1808
1809         {
1810                 {"wal_segment_size", PGC_INTERNAL, PRESET_OPTIONS,
1811                         gettext_noop("Shows the number of pages per write ahead log segment."),
1812                         NULL,
1813                         GUC_UNIT_XBLOCKS | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1814                 },
1815                 &wal_segment_size,
1816                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1817                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1818                 (XLOG_SEG_SIZE / XLOG_BLCKSZ),
1819                 NULL, NULL
1820         },
1821
1822         {
1823                 {"autovacuum_naptime", PGC_SIGHUP, AUTOVACUUM,
1824                         gettext_noop("Time to sleep between autovacuum runs."),
1825                         NULL,
1826                         GUC_UNIT_S
1827                 },
1828                 &autovacuum_naptime,
1829                 60, 1, INT_MAX / 1000, NULL, NULL
1830         },
1831         {
1832                 {"autovacuum_vacuum_threshold", PGC_SIGHUP, AUTOVACUUM,
1833                         gettext_noop("Minimum number of tuple updates or deletes prior to vacuum."),
1834                         NULL
1835                 },
1836                 &autovacuum_vac_thresh,
1837                 50, 0, INT_MAX, NULL, NULL
1838         },
1839         {
1840                 {"autovacuum_analyze_threshold", PGC_SIGHUP, AUTOVACUUM,
1841                         gettext_noop("Minimum number of tuple inserts, updates or deletes prior to analyze."),
1842                         NULL
1843                 },
1844                 &autovacuum_anl_thresh,
1845                 50, 0, INT_MAX, NULL, NULL
1846         },
1847         {
1848                 /* see varsup.c for why this is PGC_POSTMASTER not PGC_SIGHUP */
1849                 {"autovacuum_freeze_max_age", PGC_POSTMASTER, AUTOVACUUM,
1850                         gettext_noop("Age at which to autovacuum a table to prevent transaction ID wraparound."),
1851                         NULL
1852                 },
1853                 &autovacuum_freeze_max_age,
1854                 200000000, 100000000, 2000000000, NULL, NULL
1855         },
1856         {
1857                 /* see max_connections */
1858                 {"autovacuum_max_workers", PGC_POSTMASTER, AUTOVACUUM,
1859                         gettext_noop("Sets the maximum number of simultaneously running autovacuum worker processes."),
1860                         NULL
1861                 },
1862                 &autovacuum_max_workers,
1863                 3, 1, INT_MAX / 4, assign_autovacuum_max_workers, NULL
1864         },
1865
1866         {
1867                 {"tcp_keepalives_idle", PGC_USERSET, CLIENT_CONN_OTHER,
1868                         gettext_noop("Time between issuing TCP keepalives."),
1869                         gettext_noop("A value of 0 uses the system default."),
1870                         GUC_UNIT_S
1871                 },
1872                 &tcp_keepalives_idle,
1873                 0, 0, INT_MAX, assign_tcp_keepalives_idle, show_tcp_keepalives_idle
1874         },
1875
1876         {
1877                 {"tcp_keepalives_interval", PGC_USERSET, CLIENT_CONN_OTHER,
1878                         gettext_noop("Time between TCP keepalive retransmits."),
1879                         gettext_noop("A value of 0 uses the system default."),
1880                         GUC_UNIT_S
1881                 },
1882                 &tcp_keepalives_interval,
1883                 0, 0, INT_MAX, assign_tcp_keepalives_interval, show_tcp_keepalives_interval
1884         },
1885
1886         {
1887                 {"tcp_keepalives_count", PGC_USERSET, CLIENT_CONN_OTHER,
1888                         gettext_noop("Maximum number of TCP keepalive retransmits."),
1889                         gettext_noop("This controls the number of consecutive keepalive retransmits that can be "
1890                                                  "lost before a connection is considered dead. A value of 0 uses the "
1891                                                  "system default."),
1892                 },
1893                 &tcp_keepalives_count,
1894                 0, 0, INT_MAX, assign_tcp_keepalives_count, show_tcp_keepalives_count
1895         },
1896
1897         {
1898                 {"gin_fuzzy_search_limit", PGC_USERSET, CLIENT_CONN_OTHER,
1899                         gettext_noop("Sets the maximum allowed result for exact search by GIN."),
1900                         NULL,
1901                         0
1902                 },
1903                 &GinFuzzySearchLimit,
1904                 0, 0, INT_MAX, NULL, NULL
1905         },
1906
1907         {
1908                 {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST,
1909                         gettext_noop("Sets the planner's assumption about the size of the disk cache."),
1910                         gettext_noop("That is, the portion of the kernel's disk cache that "
1911                                                  "will be used for PostgreSQL data files. This is measured in disk "
1912                                                  "pages, which are normally 8 kB each."),
1913                         GUC_UNIT_BLOCKS,
1914                 },
1915                 &effective_cache_size,
1916                 DEFAULT_EFFECTIVE_CACHE_SIZE, 1, INT_MAX, NULL, NULL
1917         },
1918
1919         {
1920                 /* Can't be set in postgresql.conf */
1921                 {"server_version_num", PGC_INTERNAL, PRESET_OPTIONS,
1922                         gettext_noop("Shows the server version as an integer."),
1923                         NULL,
1924                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
1925                 },
1926                 &server_version_num,
1927                 PG_VERSION_NUM, PG_VERSION_NUM, PG_VERSION_NUM, NULL, NULL
1928         },
1929
1930         {
1931                 {"log_temp_files", PGC_SUSET, LOGGING_WHAT,
1932                         gettext_noop("Log the use of temporary files larger than this number of kilobytes."),
1933                         gettext_noop("Zero logs all files. The default is -1 (turning this feature off)."),
1934                         GUC_UNIT_KB
1935                 },
1936                 &log_temp_files,
1937                 -1, -1, INT_MAX, NULL, NULL
1938         },
1939
1940         {
1941                 {"track_activity_query_size", PGC_POSTMASTER, RESOURCES_MEM,
1942                         gettext_noop("Sets the size reserved for pg_stat_activity.current_query, in bytes."),
1943                         NULL,
1944                 },
1945                 &pgstat_track_activity_query_size,
1946                 1024, 100, 102400, NULL, NULL
1947         },
1948
1949         /* End-of-list marker */
1950         {
1951                 {NULL, 0, 0, NULL, NULL}, NULL, 0, 0, 0, NULL, NULL
1952         }
1953 };
1954
1955
1956 static struct config_real ConfigureNamesReal[] =
1957 {
1958         {
1959                 {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1960                         gettext_noop("Sets the planner's estimate of the cost of a "
1961                                                  "sequentially fetched disk page."),
1962                         NULL
1963                 },
1964                 &seq_page_cost,
1965                 DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL
1966         },
1967         {
1968                 {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST,
1969                         gettext_noop("Sets the planner's estimate of the cost of a "
1970                                                  "nonsequentially fetched disk page."),
1971                         NULL
1972                 },
1973                 &random_page_cost,
1974                 DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, NULL, NULL
1975         },
1976         {
1977                 {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1978                         gettext_noop("Sets the planner's estimate of the cost of "
1979                                                  "processing each tuple (row)."),
1980                         NULL
1981                 },
1982                 &cpu_tuple_cost,
1983                 DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1984         },
1985         {
1986                 {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST,
1987                         gettext_noop("Sets the planner's estimate of the cost of "
1988                                                  "processing each index entry during an index scan."),
1989                         NULL
1990                 },
1991                 &cpu_index_tuple_cost,
1992                 DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL
1993         },
1994         {
1995                 {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST,
1996                         gettext_noop("Sets the planner's estimate of the cost of "
1997                                                  "processing each operator or function call."),
1998                         NULL
1999                 },
2000                 &cpu_operator_cost,
2001                 DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL
2002         },
2003
2004         {
2005                 {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER,
2006                         gettext_noop("Sets the planner's estimate of the fraction of "
2007                                                  "a cursor's rows that will be retrieved."),
2008                         NULL
2009                 },
2010                 &cursor_tuple_fraction,
2011                 DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL
2012         },
2013
2014         {
2015                 {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO,
2016                         gettext_noop("GEQO: selective pressure within the population."),
2017                         NULL
2018                 },
2019                 &Geqo_selection_bias,
2020                 DEFAULT_GEQO_SELECTION_BIAS, MIN_GEQO_SELECTION_BIAS,
2021                 MAX_GEQO_SELECTION_BIAS, NULL, NULL
2022         },
2023
2024         {
2025                 {"bgwriter_lru_multiplier", PGC_SIGHUP, RESOURCES,
2026                         gettext_noop("Multiple of the average buffer usage to free per round."),
2027                         NULL
2028                 },
2029                 &bgwriter_lru_multiplier,
2030                 2.0, 0.0, 10.0, NULL, NULL
2031         },
2032
2033         {
2034                 {"seed", PGC_USERSET, UNGROUPED,
2035                         gettext_noop("Sets the seed for random-number generation."),
2036                         NULL,
2037                         GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2038                 },
2039                 &phony_random_seed,
2040                 0.0, -1.0, 1.0, assign_random_seed, show_random_seed
2041         },
2042
2043         {
2044                 {"autovacuum_vacuum_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2045                         gettext_noop("Number of tuple updates or deletes prior to vacuum as a fraction of reltuples."),
2046                         NULL
2047                 },
2048                 &autovacuum_vac_scale,
2049                 0.2, 0.0, 100.0, NULL, NULL
2050         },
2051         {
2052                 {"autovacuum_analyze_scale_factor", PGC_SIGHUP, AUTOVACUUM,
2053                         gettext_noop("Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples."),
2054                         NULL
2055                 },
2056                 &autovacuum_anl_scale,
2057                 0.1, 0.0, 100.0, NULL, NULL
2058         },
2059
2060         {
2061                 {"checkpoint_completion_target", PGC_SIGHUP, WAL_CHECKPOINTS,
2062                         gettext_noop("Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval."),
2063                         NULL
2064                 },
2065                 &CheckPointCompletionTarget,
2066                 0.5, 0.0, 1.0, NULL, NULL
2067         },
2068
2069         /* End-of-list marker */
2070         {
2071                 {NULL, 0, 0, NULL, NULL}, NULL, 0.0, 0.0, 0.0, NULL, NULL
2072         }
2073 };
2074
2075
2076 static struct config_string ConfigureNamesString[] =
2077 {
2078         {
2079                 {"archive_command", PGC_SIGHUP, WAL_SETTINGS,
2080                         gettext_noop("Sets the shell command that will be called to archive a WAL file."),
2081                         NULL
2082                 },
2083                 &XLogArchiveCommand,
2084                 "", NULL, show_archive_command
2085         },
2086
2087         {
2088                 {"client_encoding", PGC_USERSET, CLIENT_CONN_LOCALE,
2089                         gettext_noop("Sets the client's character set encoding."),
2090                         NULL,
2091                         GUC_IS_NAME | GUC_REPORT
2092                 },
2093                 &client_encoding_string,
2094                 "SQL_ASCII", assign_client_encoding, NULL
2095         },
2096
2097         {
2098                 {"log_line_prefix", PGC_SIGHUP, LOGGING_WHAT,
2099                         gettext_noop("Controls information prefixed to each log line."),
2100                         gettext_noop("If blank, no prefix is used.")
2101                 },
2102                 &Log_line_prefix,
2103                 "", NULL, NULL
2104         },
2105
2106         {
2107                 {"log_timezone", PGC_SIGHUP, LOGGING_WHAT,
2108                         gettext_noop("Sets the time zone to use in log messages."),
2109                         NULL
2110                 },
2111                 &log_timezone_string,
2112                 "UNKNOWN", assign_log_timezone, show_log_timezone
2113         },
2114
2115         {
2116                 {"DateStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2117                         gettext_noop("Sets the display format for date and time values."),
2118                         gettext_noop("Also controls interpretation of ambiguous "
2119                                                  "date inputs."),
2120                         GUC_LIST_INPUT | GUC_REPORT
2121                 },
2122                 &datestyle_string,
2123                 "ISO, MDY", assign_datestyle, NULL
2124         },
2125
2126         {
2127                 {"default_tablespace", PGC_USERSET, CLIENT_CONN_STATEMENT,
2128                         gettext_noop("Sets the default tablespace to create tables and indexes in."),
2129                         gettext_noop("An empty string selects the database's default tablespace."),
2130                         GUC_IS_NAME
2131                 },
2132                 &default_tablespace,
2133                 "", assign_default_tablespace, NULL
2134         },
2135
2136         {
2137                 {"temp_tablespaces", PGC_USERSET, CLIENT_CONN_STATEMENT,
2138                         gettext_noop("Sets the tablespace(s) to use for temporary tables and sort files."),
2139                         NULL,
2140                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2141                 },
2142                 &temp_tablespaces,
2143                 "", assign_temp_tablespaces, NULL
2144         },
2145
2146         {
2147                 {"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
2148                         gettext_noop("Sets the path for dynamically loadable modules."),
2149                         gettext_noop("If a dynamically loadable module needs to be opened and "
2150                                                  "the specified name does not have a directory component (i.e., the "
2151                                                  "name does not contain a slash), the system will search this path for "
2152                                                  "the specified file."),
2153                         GUC_SUPERUSER_ONLY
2154                 },
2155                 &Dynamic_library_path,
2156                 "$libdir", NULL, NULL
2157         },
2158
2159         {
2160                 {"krb_server_keyfile", PGC_SIGHUP, CONN_AUTH_SECURITY,
2161                         gettext_noop("Sets the location of the Kerberos server key file."),
2162                         NULL,
2163                         GUC_SUPERUSER_ONLY
2164                 },
2165                 &pg_krb_server_keyfile,
2166                 PG_KRB_SRVTAB, NULL, NULL
2167         },
2168
2169         {
2170                 {"krb_srvname", PGC_SIGHUP, CONN_AUTH_SECURITY,
2171                         gettext_noop("Sets the name of the Kerberos service."),
2172                         NULL
2173                 },
2174                 &pg_krb_srvnam,
2175                 PG_KRB_SRVNAM, NULL, NULL
2176         },
2177
2178         {
2179                 {"bonjour_name", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2180                         gettext_noop("Sets the Bonjour broadcast service name."),
2181                         NULL
2182                 },
2183                 &bonjour_name,
2184                 "", NULL, NULL
2185         },
2186
2187         /* See main.c about why defaults for LC_foo are not all alike */
2188
2189         {
2190                 {"lc_collate", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2191                         gettext_noop("Shows the collation order locale."),
2192                         NULL,
2193                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2194                 },
2195                 &locale_collate,
2196                 "C", NULL, NULL
2197         },
2198
2199         {
2200                 {"lc_ctype", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2201                         gettext_noop("Shows the character classification and case conversion locale."),
2202                         NULL,
2203                         GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2204                 },
2205                 &locale_ctype,
2206                 "C", NULL, NULL
2207         },
2208
2209         {
2210                 {"lc_messages", PGC_SUSET, CLIENT_CONN_LOCALE,
2211                         gettext_noop("Sets the language in which messages are displayed."),
2212                         NULL
2213                 },
2214                 &locale_messages,
2215                 "", locale_messages_assign, NULL
2216         },
2217
2218         {
2219                 {"lc_monetary", PGC_USERSET, CLIENT_CONN_LOCALE,
2220                         gettext_noop("Sets the locale for formatting monetary amounts."),
2221                         NULL
2222                 },
2223                 &locale_monetary,
2224                 "C", locale_monetary_assign, NULL
2225         },
2226
2227         {
2228                 {"lc_numeric", PGC_USERSET, CLIENT_CONN_LOCALE,
2229                         gettext_noop("Sets the locale for formatting numbers."),
2230                         NULL
2231                 },
2232                 &locale_numeric,
2233                 "C", locale_numeric_assign, NULL
2234         },
2235
2236         {
2237                 {"lc_time", PGC_USERSET, CLIENT_CONN_LOCALE,
2238                         gettext_noop("Sets the locale for formatting date and time values."),
2239                         NULL
2240                 },
2241                 &locale_time,
2242                 "C", locale_time_assign, NULL
2243         },
2244
2245         {
2246                 {"shared_preload_libraries", PGC_POSTMASTER, RESOURCES_KERNEL,
2247                         gettext_noop("Lists shared libraries to preload into server."),
2248                         NULL,
2249                         GUC_LIST_INPUT | GUC_LIST_QUOTE | GUC_SUPERUSER_ONLY
2250                 },
2251                 &shared_preload_libraries_string,
2252                 "", NULL, NULL
2253         },
2254
2255         {
2256                 {"local_preload_libraries", PGC_BACKEND, CLIENT_CONN_OTHER,
2257                         gettext_noop("Lists shared libraries to preload into each backend."),
2258                         NULL,
2259                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2260                 },
2261                 &local_preload_libraries_string,
2262                 "", NULL, NULL
2263         },
2264
2265         {
2266                 {"search_path", PGC_USERSET, CLIENT_CONN_STATEMENT,
2267                         gettext_noop("Sets the schema search order for names that are not schema-qualified."),
2268                         NULL,
2269                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2270                 },
2271                 &namespace_search_path,
2272                 "\"$user\",public", assign_search_path, NULL
2273         },
2274
2275         {
2276                 /* Can't be set in postgresql.conf */
2277                 {"server_encoding", PGC_INTERNAL, CLIENT_CONN_LOCALE,
2278                         gettext_noop("Sets the server (database) character set encoding."),
2279                         NULL,
2280                         GUC_IS_NAME | GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2281                 },
2282                 &server_encoding_string,
2283                 "SQL_ASCII", NULL, NULL
2284         },
2285
2286         {
2287                 /* Can't be set in postgresql.conf */
2288                 {"server_version", PGC_INTERNAL, PRESET_OPTIONS,
2289                         gettext_noop("Shows the server version."),
2290                         NULL,
2291                         GUC_REPORT | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2292                 },
2293                 &server_version_string,
2294                 PG_VERSION, NULL, NULL
2295         },
2296
2297         {
2298                 /* Not for general use --- used by SET ROLE */
2299                 {"role", PGC_USERSET, UNGROUPED,
2300                         gettext_noop("Sets the current role."),
2301                         NULL,
2302                         GUC_IS_NAME | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2303                 },
2304                 &role_string,
2305                 "none", assign_role, show_role
2306         },
2307
2308         {
2309                 /* Not for general use --- used by SET SESSION AUTHORIZATION */
2310                 {"session_authorization", PGC_USERSET, UNGROUPED,
2311                         gettext_noop("Sets the session user name."),
2312                         NULL,
2313                         GUC_IS_NAME | GUC_REPORT | GUC_NO_SHOW_ALL | GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2314                 },
2315                 &session_authorization_string,
2316                 NULL, assign_session_authorization, show_session_authorization
2317         },
2318
2319         {
2320                 {"log_destination", PGC_SIGHUP, LOGGING_WHERE,
2321                         gettext_noop("Sets the destination for server log output."),
2322                         gettext_noop("Valid values are combinations of \"stderr\", "
2323                                                  "\"syslog\", \"csvlog\", and \"eventlog\", "
2324                                                  "depending on the platform."),
2325                         GUC_LIST_INPUT
2326                 },
2327                 &log_destination_string,
2328                 "stderr", assign_log_destination, NULL
2329         },
2330         {
2331                 {"log_directory", PGC_SIGHUP, LOGGING_WHERE,
2332                         gettext_noop("Sets the destination directory for log files."),
2333                         gettext_noop("Can be specified as relative to the data directory "
2334                                                  "or as absolute path."),
2335                         GUC_SUPERUSER_ONLY
2336                 },
2337                 &Log_directory,
2338                 "pg_log", assign_canonical_path, NULL
2339         },
2340         {
2341                 {"log_filename", PGC_SIGHUP, LOGGING_WHERE,
2342                         gettext_noop("Sets the file name pattern for log files."),
2343                         NULL,
2344                         GUC_SUPERUSER_ONLY
2345                 },
2346                 &Log_filename,
2347                 "postgresql-%Y-%m-%d_%H%M%S.log", NULL, NULL
2348         },
2349
2350 #ifdef HAVE_SYSLOG
2351         {
2352                 {"syslog_ident", PGC_SIGHUP, LOGGING_WHERE,
2353                         gettext_noop("Sets the program name used to identify PostgreSQL "
2354                                                  "messages in syslog."),
2355                         NULL
2356                 },
2357                 &syslog_ident_str,
2358                 "postgres", assign_syslog_ident, NULL
2359         },
2360 #endif
2361
2362         {
2363                 {"TimeZone", PGC_USERSET, CLIENT_CONN_LOCALE,
2364                         gettext_noop("Sets the time zone for displaying and interpreting time stamps."),
2365                         NULL,
2366                         GUC_REPORT
2367                 },
2368                 &timezone_string,
2369                 "UNKNOWN", assign_timezone, show_timezone
2370         },
2371         {
2372                 {"timezone_abbreviations", PGC_USERSET, CLIENT_CONN_LOCALE,
2373                         gettext_noop("Selects a file of time zone abbreviations."),
2374                         NULL
2375                 },
2376                 &timezone_abbreviations_string,
2377                 "UNKNOWN", assign_timezone_abbreviations, NULL
2378         },
2379
2380         {
2381                 {"transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2382                         gettext_noop("Sets the current transaction's isolation level."),
2383                         NULL,
2384                         GUC_NO_RESET_ALL | GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
2385                 },
2386                 &XactIsoLevel_string,
2387                 NULL, assign_XactIsoLevel, show_XactIsoLevel
2388         },
2389
2390         {
2391                 {"unix_socket_group", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2392                         gettext_noop("Sets the owning group of the Unix-domain socket."),
2393                         gettext_noop("The owning user of the socket is always the user "
2394                                                  "that starts the server.")
2395                 },
2396                 &Unix_socket_group,
2397                 "", NULL, NULL
2398         },
2399
2400         {
2401                 {"unix_socket_directory", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2402                         gettext_noop("Sets the directory where the Unix-domain socket will be created."),
2403                         NULL,
2404                         GUC_SUPERUSER_ONLY
2405                 },
2406                 &UnixSocketDir,
2407                 "", assign_canonical_path, NULL
2408         },
2409
2410         {
2411                 {"listen_addresses", PGC_POSTMASTER, CONN_AUTH_SETTINGS,
2412                         gettext_noop("Sets the host name or IP address(es) to listen to."),
2413                         NULL,
2414                         GUC_LIST_INPUT
2415                 },
2416                 &ListenAddresses,
2417                 "localhost", NULL, NULL
2418         },
2419
2420         {
2421                 {"custom_variable_classes", PGC_SIGHUP, CUSTOM_OPTIONS,
2422                         gettext_noop("Sets the list of known custom variable classes."),
2423                         NULL,
2424                         GUC_LIST_INPUT | GUC_LIST_QUOTE
2425                 },
2426                 &custom_variable_classes,
2427                 NULL, assign_custom_variable_classes, NULL
2428         },
2429
2430         {
2431                 {"data_directory", PGC_POSTMASTER, FILE_LOCATIONS,
2432                         gettext_noop("Sets the server's data directory."),
2433                         NULL,
2434                         GUC_SUPERUSER_ONLY
2435                 },
2436                 &data_directory,
2437                 NULL, NULL, NULL
2438         },
2439
2440         {
2441                 {"config_file", PGC_POSTMASTER, FILE_LOCATIONS,
2442                         gettext_noop("Sets the server's main configuration file."),
2443                         NULL,
2444                         GUC_DISALLOW_IN_FILE | GUC_SUPERUSER_ONLY
2445                 },
2446                 &ConfigFileName,
2447                 NULL, NULL, NULL
2448         },
2449
2450         {
2451                 {"hba_file", PGC_POSTMASTER, FILE_LOCATIONS,
2452                         gettext_noop("Sets the server's \"hba\" configuration file."),
2453                         NULL,
2454                         GUC_SUPERUSER_ONLY
2455                 },
2456                 &HbaFileName,
2457                 NULL, NULL, NULL
2458         },
2459
2460         {
2461                 {"ident_file", PGC_POSTMASTER, FILE_LOCATIONS,
2462                         gettext_noop("Sets the server's \"ident\" configuration file."),
2463                         NULL,
2464                         GUC_SUPERUSER_ONLY
2465                 },
2466                 &IdentFileName,
2467                 NULL, NULL, NULL
2468         },
2469
2470         {
2471                 {"external_pid_file", PGC_POSTMASTER, FILE_LOCATIONS,
2472                         gettext_noop("Writes the postmaster PID to the specified file."),
2473                         NULL,
2474                         GUC_SUPERUSER_ONLY
2475                 },
2476                 &external_pid_file,
2477                 NULL, assign_canonical_path, NULL
2478         },
2479
2480         {
2481                 {"stats_temp_directory", PGC_SIGHUP, STATS_COLLECTOR,
2482                         gettext_noop("Writes temporary statistics files to the specified directory."),
2483                         NULL,
2484                         GUC_SUPERUSER_ONLY
2485                 },
2486                 &pgstat_temp_directory,
2487                 "pg_stat_tmp", assign_pgstat_temp_directory, NULL
2488         },
2489
2490         {
2491                 {"default_text_search_config", PGC_USERSET, CLIENT_CONN_LOCALE,
2492                         gettext_noop("Sets default text search configuration."),
2493                         NULL
2494                 },
2495                 &TSCurrentConfig,
2496                 "pg_catalog.simple", assignTSCurrentConfig, NULL
2497         },
2498
2499 #ifdef USE_SSL
2500         {
2501                 {"ssl_ciphers", PGC_POSTMASTER, CONN_AUTH_SECURITY,
2502                         gettext_noop("Sets the list of allowed SSL ciphers."),
2503                         NULL,
2504                         GUC_SUPERUSER_ONLY
2505                 },
2506                 &SSLCipherSuites,
2507                 "ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH", NULL, NULL
2508         },
2509 #endif   /* USE_SSL */
2510
2511         /* End-of-list marker */
2512         {
2513                 {NULL, 0, 0, NULL, NULL}, NULL, NULL, NULL, NULL
2514         }
2515 };
2516
2517
2518 static struct config_enum ConfigureNamesEnum[] =
2519 {
2520         {
2521                 {"backslash_quote", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2522                         gettext_noop("Sets whether \"\\'\" is allowed in string literals."),
2523                         NULL
2524                 },
2525                 &backslash_quote,
2526                 BACKSLASH_QUOTE_SAFE_ENCODING, backslash_quote_options, NULL, NULL
2527         },
2528
2529         {
2530                 {"client_min_messages", PGC_USERSET, LOGGING_WHEN,
2531                         gettext_noop("Sets the message levels that are sent to the client."),
2532                         gettext_noop("Each level includes all the levels that follow it. The later"
2533                                                  " the level, the fewer messages are sent.")
2534                 },
2535                 &client_min_messages,
2536                 NOTICE, client_message_level_options, NULL, NULL
2537         },
2538
2539         {
2540                 {"constraint_exclusion", PGC_USERSET, QUERY_TUNING_OTHER,
2541                         gettext_noop("Enables the planner to use constraints to optimize queries."),
2542                         gettext_noop("Table scans will be skipped if their constraints"
2543                                                  " guarantee that no rows match the query.")
2544                 },
2545                 &constraint_exclusion,
2546                 CONSTRAINT_EXCLUSION_PARTITION, constraint_exclusion_options,
2547                 NULL, NULL
2548         },
2549
2550         {
2551                 {"default_transaction_isolation", PGC_USERSET, CLIENT_CONN_STATEMENT,
2552                         gettext_noop("Sets the transaction isolation level of each new transaction."),
2553                         NULL
2554                 },
2555                 &DefaultXactIsoLevel,
2556                 XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
2557         },
2558
2559         {
2560                 {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
2561                         gettext_noop("Sets the display format for interval values."),
2562                         NULL,
2563                         GUC_REPORT
2564                 },
2565                 &IntervalStyle,
2566                 INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
2567         },
2568
2569         {
2570                 {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
2571                         gettext_noop("Sets the verbosity of logged messages."),
2572                         NULL
2573                 },
2574                 &Log_error_verbosity,
2575                 PGERROR_DEFAULT, log_error_verbosity_options, NULL, NULL
2576         },
2577
2578         {
2579                 {"log_min_messages", PGC_SUSET, LOGGING_WHEN,
2580                         gettext_noop("Sets the message levels that are logged."),
2581                         gettext_noop("Each level includes all the levels that follow it. The later"
2582                                                  " the level, the fewer messages are sent.")
2583                 },
2584                 &log_min_messages,
2585                 WARNING, server_message_level_options, NULL, NULL
2586         },
2587
2588         {
2589                 {"log_min_error_statement", PGC_SUSET, LOGGING_WHEN,
2590                         gettext_noop("Causes all statements generating error at or above this level to be logged."),
2591                         gettext_noop("Each level includes all the levels that follow it. The later"
2592                                                  " the level, the fewer messages are sent.")
2593                 },
2594                 &log_min_error_statement,
2595                 ERROR, server_message_level_options, NULL, NULL
2596         },
2597
2598         {
2599                 {"log_statement", PGC_SUSET, LOGGING_WHAT,
2600                         gettext_noop("Sets the type of statements logged."),
2601                         NULL
2602                 },
2603                 &log_statement,
2604                 LOGSTMT_NONE, log_statement_options, NULL, NULL
2605         },
2606
2607 #ifdef HAVE_SYSLOG
2608         {
2609                 {"syslog_facility", PGC_SIGHUP, LOGGING_WHERE,
2610                         gettext_noop("Sets the syslog \"facility\" to be used when syslog enabled."),
2611                         NULL
2612                 },
2613                 &syslog_facility,
2614                 LOG_LOCAL0, syslog_facility_options, assign_syslog_facility, NULL
2615         },
2616 #endif
2617
2618         {
2619                 {"regex_flavor", PGC_USERSET, COMPAT_OPTIONS_PREVIOUS,
2620                         gettext_noop("Sets the regular expression \"flavor\"."),
2621                         NULL
2622                 },
2623                 &regex_flavor,
2624                 REG_ADVANCED, regex_flavor_options, NULL, NULL
2625         },
2626
2627         {
2628                 {"session_replication_role", PGC_SUSET, CLIENT_CONN_STATEMENT,
2629                         gettext_noop("Sets the session's behavior for triggers and rewrite rules."),
2630                         NULL
2631                 },
2632                 &SessionReplicationRole,
2633                 SESSION_REPLICATION_ROLE_ORIGIN, session_replication_role_options,
2634                 assign_session_replication_role, NULL
2635         },
2636
2637         {
2638                 {"track_functions", PGC_SUSET, STATS_COLLECTOR,
2639                         gettext_noop("Collects function-level statistics on database activity."),
2640                         NULL
2641                 },
2642                 &pgstat_track_functions,
2643                 TRACK_FUNC_OFF, track_function_options, NULL, NULL
2644         },
2645
2646         {
2647                 {"wal_sync_method", PGC_SIGHUP, WAL_SETTINGS,
2648                         gettext_noop("Selects the method used for forcing WAL updates to disk."),
2649                         NULL
2650                 },
2651                 &sync_method,
2652                 DEFAULT_SYNC_METHOD, sync_method_options,
2653                 assign_xlog_sync_method, NULL
2654         },
2655
2656         {
2657                 {"xmlbinary", PGC_USERSET, CLIENT_CONN_STATEMENT,
2658                         gettext_noop("Sets how binary values are to be encoded in XML."),
2659                         NULL
2660                 },
2661                 &xmlbinary,
2662                 XMLBINARY_BASE64, xmlbinary_options, NULL, NULL
2663         },
2664
2665         {
2666                 {"xmloption", PGC_USERSET, CLIENT_CONN_STATEMENT,
2667                         gettext_noop("Sets whether XML data in implicit parsing and serialization "
2668                                                  "operations is to be considered as documents or content fragments."),
2669                         NULL
2670                 },
2671                 &xmloption,
2672                 XMLOPTION_CONTENT, xmloption_options, NULL, NULL
2673         },
2674
2675
2676         /* End-of-list marker */
2677         {
2678                 {NULL, 0, 0, NULL, NULL}, NULL, 0, NULL, NULL, NULL
2679         }
2680 };
2681
2682 /******** end of options list ********/
2683
2684
2685 /*
2686  * To allow continued support of obsolete names for GUC variables, we apply
2687  * the following mappings to any unrecognized name.  Note that an old name
2688  * should be mapped to a new one only if the new variable has very similar
2689  * semantics to the old.
2690  */
2691 static const char *const map_old_guc_names[] = {
2692         "sort_mem", "work_mem",
2693         "vacuum_mem", "maintenance_work_mem",
2694         NULL
2695 };
2696
2697
2698 /*
2699  * Actual lookup of variables is done through this single, sorted array.
2700  */
2701 static struct config_generic **guc_variables;
2702
2703 /* Current number of variables contained in the vector */
2704 static int      num_guc_variables;
2705
2706 /* Vector capacity */
2707 static int      size_guc_variables;
2708
2709
2710 static bool guc_dirty;                  /* TRUE if need to do commit/abort work */
2711
2712 static bool reporting_enabled;  /* TRUE to enable GUC_REPORT */
2713
2714 static int      GUCNestLevel = 0;       /* 1 when in main transaction */
2715
2716
2717 static int      guc_var_compare(const void *a, const void *b);
2718 static int      guc_name_compare(const char *namea, const char *nameb);
2719 static void InitializeOneGUCOption(struct config_generic *gconf);
2720 static void push_old_value(struct config_generic * gconf, GucAction action);
2721 static void ReportGUCOption(struct config_generic * record);
2722 static void ShowGUCConfigOption(const char *name, DestReceiver *dest);
2723 static void ShowAllGUCConfig(DestReceiver *dest);
2724 static char *_ShowOption(struct config_generic * record, bool use_units);
2725 static bool is_newvalue_equal(struct config_generic * record, const char *newvalue);
2726
2727
2728 /*
2729  * Some infrastructure for checking malloc/strdup/realloc calls
2730  */
2731 static void *
2732 guc_malloc(int elevel, size_t size)
2733 {
2734         void       *data;
2735
2736         data = malloc(size);
2737         if (data == NULL)
2738                 ereport(elevel,
2739                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2740                                  errmsg("out of memory")));
2741         return data;
2742 }
2743
2744 static void *
2745 guc_realloc(int elevel, void *old, size_t size)
2746 {
2747         void       *data;
2748
2749         data = realloc(old, size);
2750         if (data == NULL)
2751                 ereport(elevel,
2752                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2753                                  errmsg("out of memory")));
2754         return data;
2755 }
2756
2757 static char *
2758 guc_strdup(int elevel, const char *src)
2759 {
2760         char       *data;
2761
2762         data = strdup(src);
2763         if (data == NULL)
2764                 ereport(elevel,
2765                                 (errcode(ERRCODE_OUT_OF_MEMORY),
2766                                  errmsg("out of memory")));
2767         return data;
2768 }
2769
2770
2771 /*
2772  * Support for assigning to a field of a string GUC item.  Free the prior
2773  * value if it's not referenced anywhere else in the item (including stacked
2774  * states).
2775  */
2776 static void
2777 set_string_field(struct config_string * conf, char **field, char *newval)
2778 {
2779         char       *oldval = *field;
2780         GucStack   *stack;
2781
2782         /* Do the assignment */
2783         *field = newval;
2784
2785         /* Exit if any duplicate references, or if old value was NULL anyway */
2786         if (oldval == NULL ||
2787                 oldval == *(conf->variable) ||
2788                 oldval == conf->reset_val ||
2789                 oldval == conf->boot_val)
2790                 return;
2791         for (stack = conf->gen.stack; stack; stack = stack->prev)
2792         {
2793                 if (oldval == stack->prior.stringval ||
2794                         oldval == stack->masked.stringval)
2795                         return;
2796         }
2797
2798         /* Not used anymore, so free it */
2799         free(oldval);
2800 }
2801
2802 /*
2803  * Detect whether strval is referenced anywhere in a GUC string item
2804  */
2805 static bool
2806 string_field_used(struct config_string * conf, char *strval)
2807 {
2808         GucStack   *stack;
2809
2810         if (strval == *(conf->variable) ||
2811                 strval == conf->reset_val ||
2812                 strval == conf->boot_val)
2813                 return true;
2814         for (stack = conf->gen.stack; stack; stack = stack->prev)
2815         {
2816                 if (strval == stack->prior.stringval ||
2817                         strval == stack->masked.stringval)
2818                         return true;
2819         }
2820         return false;
2821 }
2822
2823 /*
2824  * Support for copying a variable's active value into a stack entry
2825  */
2826 static void
2827 set_stack_value(struct config_generic * gconf, union config_var_value * val)
2828 {
2829         switch (gconf->vartype)
2830         {
2831                 case PGC_BOOL:
2832                         val->boolval =
2833                                 *((struct config_bool *) gconf)->variable;
2834                         break;
2835                 case PGC_INT:
2836                         val->intval =
2837                                 *((struct config_int *) gconf)->variable;
2838                         break;
2839                 case PGC_REAL:
2840                         val->realval =
2841                                 *((struct config_real *) gconf)->variable;
2842                         break;
2843                 case PGC_STRING:
2844                         /* we assume stringval is NULL if not valid */
2845                         set_string_field((struct config_string *) gconf,
2846                                                          &(val->stringval),
2847                                                          *((struct config_string *) gconf)->variable);
2848                         break;
2849                 case PGC_ENUM:
2850                         val->enumval =
2851                                 *((struct config_enum *) gconf)->variable;
2852                         break;
2853         }
2854 }
2855
2856 /*
2857  * Support for discarding a no-longer-needed value in a stack entry
2858  */
2859 static void
2860 discard_stack_value(struct config_generic * gconf, union config_var_value * val)
2861 {
2862         switch (gconf->vartype)
2863         {
2864                 case PGC_BOOL:
2865                 case PGC_INT:
2866                 case PGC_REAL:
2867                 case PGC_ENUM:
2868                         /* no need to do anything */
2869                         break;
2870                 case PGC_STRING:
2871                         set_string_field((struct config_string *) gconf,
2872                                                          &(val->stringval),
2873                                                          NULL);
2874                         break;
2875         }
2876 }
2877
2878
2879 /*
2880  * Fetch the sorted array pointer (exported for help_config.c's use ONLY)
2881  */
2882 struct config_generic **
2883 get_guc_variables(void)
2884 {
2885         return guc_variables;
2886 }
2887
2888
2889 /*
2890  * Build the sorted array.      This is split out so that it could be
2891  * re-executed after startup (eg, we could allow loadable modules to
2892  * add vars, and then we'd need to re-sort).
2893  */
2894 void
2895 build_guc_variables(void)
2896 {
2897         int                     size_vars;
2898         int                     num_vars = 0;
2899         struct config_generic **guc_vars;
2900         int                     i;
2901
2902         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2903         {
2904                 struct config_bool *conf = &ConfigureNamesBool[i];
2905
2906                 /* Rather than requiring vartype to be filled in by hand, do this: */
2907                 conf->gen.vartype = PGC_BOOL;
2908                 num_vars++;
2909         }
2910
2911         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2912         {
2913                 struct config_int *conf = &ConfigureNamesInt[i];
2914
2915                 conf->gen.vartype = PGC_INT;
2916                 num_vars++;
2917         }
2918
2919         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2920         {
2921                 struct config_real *conf = &ConfigureNamesReal[i];
2922
2923                 conf->gen.vartype = PGC_REAL;
2924                 num_vars++;
2925         }
2926
2927         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2928         {
2929                 struct config_string *conf = &ConfigureNamesString[i];
2930
2931                 conf->gen.vartype = PGC_STRING;
2932                 num_vars++;
2933         }
2934
2935         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2936         {
2937                 struct config_enum *conf = &ConfigureNamesEnum[i];
2938
2939                 conf->gen.vartype = PGC_ENUM;
2940                 num_vars++;
2941         }
2942
2943         /*
2944          * Create table with 20% slack
2945          */
2946         size_vars = num_vars + num_vars / 4;
2947
2948         guc_vars = (struct config_generic **)
2949                 guc_malloc(FATAL, size_vars * sizeof(struct config_generic *));
2950
2951         num_vars = 0;
2952
2953         for (i = 0; ConfigureNamesBool[i].gen.name; i++)
2954                 guc_vars[num_vars++] = &ConfigureNamesBool[i].gen;
2955
2956         for (i = 0; ConfigureNamesInt[i].gen.name; i++)
2957                 guc_vars[num_vars++] = &ConfigureNamesInt[i].gen;
2958
2959         for (i = 0; ConfigureNamesReal[i].gen.name; i++)
2960                 guc_vars[num_vars++] = &ConfigureNamesReal[i].gen;
2961
2962         for (i = 0; ConfigureNamesString[i].gen.name; i++)
2963                 guc_vars[num_vars++] = &ConfigureNamesString[i].gen;
2964
2965         for (i = 0; ConfigureNamesEnum[i].gen.name; i++)
2966                 guc_vars[num_vars++] = &ConfigureNamesEnum[i].gen;
2967
2968         if (guc_variables)
2969                 free(guc_variables);
2970         guc_variables = guc_vars;
2971         num_guc_variables = num_vars;
2972         size_guc_variables = size_vars;
2973         qsort((void *) guc_variables, num_guc_variables,
2974                   sizeof(struct config_generic *), guc_var_compare);
2975 }
2976
2977 /*
2978  * Add a new GUC variable to the list of known variables. The
2979  * list is expanded if needed.
2980  */
2981 static bool
2982 add_guc_variable(struct config_generic * var, int elevel)
2983 {
2984         if (num_guc_variables + 1 >= size_guc_variables)
2985         {
2986                 /*
2987                  * Increase the vector by 25%
2988                  */
2989                 int                     size_vars = size_guc_variables + size_guc_variables / 4;
2990                 struct config_generic **guc_vars;
2991
2992                 if (size_vars == 0)
2993                 {
2994                         size_vars = 100;
2995                         guc_vars = (struct config_generic **)
2996                                 guc_malloc(elevel, size_vars * sizeof(struct config_generic *));
2997                 }
2998                 else
2999                 {
3000                         guc_vars = (struct config_generic **)
3001                                 guc_realloc(elevel, guc_variables, size_vars * sizeof(struct config_generic *));
3002                 }
3003
3004                 if (guc_vars == NULL)
3005                         return false;           /* out of memory */
3006
3007                 guc_variables = guc_vars;
3008                 size_guc_variables = size_vars;
3009         }
3010         guc_variables[num_guc_variables++] = var;
3011         qsort((void *) guc_variables, num_guc_variables,
3012                   sizeof(struct config_generic *), guc_var_compare);
3013         return true;
3014 }
3015
3016 /*
3017  * Create and add a placeholder variable. It's presumed to belong
3018  * to a valid custom variable class at this point.
3019  */
3020 static struct config_generic *
3021 add_placeholder_variable(const char *name, int elevel)
3022 {
3023         size_t          sz = sizeof(struct config_string) + sizeof(char *);
3024         struct config_string *var;
3025         struct config_generic *gen;
3026
3027         var = (struct config_string *) guc_malloc(elevel, sz);
3028         if (var == NULL)
3029                 return NULL;
3030         memset(var, 0, sz);
3031         gen = &var->gen;
3032
3033         gen->name = guc_strdup(elevel, name);
3034         if (gen->name == NULL)
3035         {
3036                 free(var);
3037                 return NULL;
3038         }
3039
3040         gen->context = PGC_USERSET;
3041         gen->group = CUSTOM_OPTIONS;
3042         gen->short_desc = "GUC placeholder variable";
3043         gen->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
3044         gen->vartype = PGC_STRING;
3045
3046         /*
3047          * The char* is allocated at the end of the struct since we have no
3048          * 'static' place to point to.  Note that the current value, as well as
3049          * the boot and reset values, start out NULL.
3050          */
3051         var->variable = (char **) (var + 1);
3052
3053         if (!add_guc_variable((struct config_generic *) var, elevel))
3054         {
3055                 free((void *) gen->name);
3056                 free(var);
3057                 return NULL;
3058         }
3059
3060         return gen;
3061 }
3062
3063 /*
3064  * Detect whether the portion of "name" before dotPos matches any custom
3065  * variable class name listed in custom_var_classes.  The latter must be
3066  * formatted the way that assign_custom_variable_classes does it, ie,
3067  * no whitespace.  NULL is valid for custom_var_classes.
3068  */
3069 static bool
3070 is_custom_class(const char *name, int dotPos, const char *custom_var_classes)
3071 {
3072         bool            result = false;
3073         const char *ccs = custom_var_classes;
3074
3075         if (ccs != NULL)
3076         {
3077                 const char *start = ccs;
3078
3079                 for (;; ++ccs)
3080                 {
3081                         char            c = *ccs;
3082
3083                         if (c == '\0' || c == ',')
3084                         {
3085                                 if (dotPos == ccs - start && strncmp(start, name, dotPos) == 0)
3086                                 {
3087                                         result = true;
3088                                         break;
3089                                 }
3090                                 if (c == '\0')
3091                                         break;
3092                                 start = ccs + 1;
3093                         }
3094                 }
3095         }
3096         return result;
3097 }
3098
3099 /*
3100  * Look up option NAME.  If it exists, return a pointer to its record,
3101  * else return NULL.  If create_placeholders is TRUE, we'll create a
3102  * placeholder record for a valid-looking custom variable name.
3103  */
3104 static struct config_generic *
3105 find_option(const char *name, bool create_placeholders, int elevel)
3106 {
3107         const char **key = &name;
3108         struct config_generic **res;
3109         int                     i;
3110
3111         Assert(name);
3112
3113         /*
3114          * By equating const char ** with struct config_generic *, we are assuming
3115          * the name field is first in config_generic.
3116          */
3117         res = (struct config_generic **) bsearch((void *) &key,
3118                                                                                          (void *) guc_variables,
3119                                                                                          num_guc_variables,
3120                                                                                          sizeof(struct config_generic *),
3121                                                                                          guc_var_compare);
3122         if (res)
3123                 return *res;
3124
3125         /*
3126          * See if the name is an obsolete name for a variable.  We assume that the
3127          * set of supported old names is short enough that a brute-force search is
3128          * the best way.
3129          */
3130         for (i = 0; map_old_guc_names[i] != NULL; i += 2)
3131         {
3132                 if (guc_name_compare(name, map_old_guc_names[i]) == 0)
3133                         return find_option(map_old_guc_names[i + 1], false, elevel);
3134         }
3135
3136         if (create_placeholders)
3137         {
3138                 /*
3139                  * Check if the name is qualified, and if so, check if the qualifier
3140                  * matches any custom variable class.  If so, add a placeholder.
3141                  */
3142                 const char *dot = strchr(name, GUC_QUALIFIER_SEPARATOR);
3143
3144                 if (dot != NULL &&
3145                         is_custom_class(name, dot - name, custom_variable_classes))
3146                         return add_placeholder_variable(name, elevel);
3147         }
3148
3149         /* Unknown name */
3150         return NULL;
3151 }
3152
3153
3154 /*
3155  * comparator for qsorting and bsearching guc_variables array
3156  */
3157 static int
3158 guc_var_compare(const void *a, const void *b)
3159 {
3160         struct config_generic *confa = *(struct config_generic **) a;
3161         struct config_generic *confb = *(struct config_generic **) b;
3162
3163         return guc_name_compare(confa->name, confb->name);
3164 }
3165
3166 /*
3167  * the bare comparison function for GUC names
3168  */
3169 static int
3170 guc_name_compare(const char *namea, const char *nameb)
3171 {
3172         /*
3173          * The temptation to use strcasecmp() here must be resisted, because the
3174          * array ordering has to remain stable across setlocale() calls. So, build
3175          * our own with a simple ASCII-only downcasing.
3176          */
3177         while (*namea && *nameb)
3178         {
3179                 char            cha = *namea++;
3180                 char            chb = *nameb++;
3181
3182                 if (cha >= 'A' && cha <= 'Z')
3183                         cha += 'a' - 'A';
3184                 if (chb >= 'A' && chb <= 'Z')
3185                         chb += 'a' - 'A';
3186                 if (cha != chb)
3187                         return cha - chb;
3188         }
3189         if (*namea)
3190                 return 1;                               /* a is longer */
3191         if (*nameb)
3192                 return -1;                              /* b is longer */
3193         return 0;
3194 }
3195
3196
3197 /*
3198  * Initialize GUC options during program startup.
3199  *
3200  * Note that we cannot read the config file yet, since we have not yet
3201  * processed command-line switches.
3202  */
3203 void
3204 InitializeGUCOptions(void)
3205 {
3206         int                     i;
3207         char       *env;
3208         long            stack_rlimit;
3209
3210         /*
3211          * Before log_line_prefix could possibly receive a nonempty setting, make
3212          * sure that timezone processing is minimally alive (see elog.c).
3213          */
3214         pg_timezone_pre_initialize();
3215
3216         /*
3217          * Build sorted array of all GUC variables.
3218          */
3219         build_guc_variables();
3220
3221         /*
3222          * Load all variables with their compiled-in defaults, and initialize
3223          * status fields as needed.
3224          */
3225         for (i = 0; i < num_guc_variables; i++)
3226         {
3227                 InitializeOneGUCOption(guc_variables[i]);
3228         }
3229
3230         guc_dirty = false;
3231
3232         reporting_enabled = false;
3233
3234         /*
3235          * Prevent any attempt to override the transaction modes from
3236          * non-interactive sources.
3237          */
3238         SetConfigOption("transaction_isolation", "default",
3239                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3240         SetConfigOption("transaction_read_only", "no",
3241                                         PGC_POSTMASTER, PGC_S_OVERRIDE);
3242
3243         /*
3244          * For historical reasons, some GUC parameters can receive defaults from
3245          * environment variables.  Process those settings.      NB: if you add or
3246          * remove anything here, see also ProcessConfigFile().
3247          */
3248
3249         env = getenv("PGPORT");
3250         if (env != NULL)
3251                 SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3252
3253         env = getenv("PGDATESTYLE");
3254         if (env != NULL)
3255                 SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3256
3257         env = getenv("PGCLIENTENCODING");
3258         if (env != NULL)
3259                 SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
3260
3261         /*
3262          * rlimit isn't exactly an "environment variable", but it behaves about
3263          * the same.  If we can identify the platform stack depth rlimit, increase
3264          * default stack depth setting up to whatever is safe (but at most 2MB).
3265          */
3266         stack_rlimit = get_stack_depth_rlimit();
3267         if (stack_rlimit > 0)
3268         {
3269                 int                     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024L;
3270
3271                 if (new_limit > 100)
3272                 {
3273                         char            limbuf[16];
3274
3275                         new_limit = Min(new_limit, 2048);
3276                         sprintf(limbuf, "%d", new_limit);
3277                         SetConfigOption("max_stack_depth", limbuf,
3278                                                         PGC_POSTMASTER, PGC_S_ENV_VAR);
3279                 }
3280         }
3281 }
3282
3283 /*
3284  * Initialize one GUC option variable to its compiled-in default.
3285  */
3286 static void
3287 InitializeOneGUCOption(struct config_generic *gconf)
3288 {
3289         gconf->status = 0;
3290         gconf->reset_source = PGC_S_DEFAULT;
3291         gconf->source = PGC_S_DEFAULT;
3292         gconf->stack = NULL;
3293         gconf->sourcefile = NULL;
3294         gconf->sourceline = 0;
3295
3296         switch (gconf->vartype)
3297         {
3298                 case PGC_BOOL:
3299                 {
3300                         struct config_bool *conf = (struct config_bool *) gconf;
3301
3302                         if (conf->assign_hook)
3303                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3304                                                                                    PGC_S_DEFAULT))
3305                                         elog(FATAL, "failed to initialize %s to %d",
3306                                                  conf->gen.name, (int) conf->boot_val);
3307                         *conf->variable = conf->reset_val = conf->boot_val;
3308                         break;
3309                 }
3310                 case PGC_INT:
3311                 {
3312                         struct config_int *conf = (struct config_int *) gconf;
3313
3314                         Assert(conf->boot_val >= conf->min);
3315                         Assert(conf->boot_val <= conf->max);
3316                         if (conf->assign_hook)
3317                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3318                                                                                    PGC_S_DEFAULT))
3319                                         elog(FATAL, "failed to initialize %s to %d",
3320                                                  conf->gen.name, conf->boot_val);
3321                         *conf->variable = conf->reset_val = conf->boot_val;
3322                         break;
3323                 }
3324                 case PGC_REAL:
3325                 {
3326                         struct config_real *conf = (struct config_real *) gconf;
3327
3328                         Assert(conf->boot_val >= conf->min);
3329                         Assert(conf->boot_val <= conf->max);
3330                         if (conf->assign_hook)
3331                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3332                                                                                    PGC_S_DEFAULT))
3333                                         elog(FATAL, "failed to initialize %s to %g",
3334                                                  conf->gen.name, conf->boot_val);
3335                         *conf->variable = conf->reset_val = conf->boot_val;
3336                         break;
3337                 }
3338                 case PGC_STRING:
3339                 {
3340                         struct config_string *conf = (struct config_string *) gconf;
3341                         char       *str;
3342
3343                         *conf->variable = NULL;
3344                         conf->reset_val = NULL;
3345
3346                         if (conf->boot_val == NULL)
3347                         {
3348                                 /* leave the value NULL, do not call assign hook */
3349                                 break;
3350                         }
3351
3352                         str = guc_strdup(FATAL, conf->boot_val);
3353                         conf->reset_val = str;
3354
3355                         if (conf->assign_hook)
3356                         {
3357                                 const char *newstr;
3358
3359                                 newstr = (*conf->assign_hook) (str, true,
3360                                                                                            PGC_S_DEFAULT);
3361                                 if (newstr == NULL)
3362                                 {
3363                                         elog(FATAL, "failed to initialize %s to \"%s\"",
3364                                                  conf->gen.name, str);
3365                                 }
3366                                 else if (newstr != str)
3367                                 {
3368                                         free(str);
3369
3370                                         /*
3371                                          * See notes in set_config_option about casting
3372                                          */
3373                                         str = (char *) newstr;
3374                                         conf->reset_val = str;
3375                                 }
3376                         }
3377                         *conf->variable = str;
3378                         break;
3379                 }
3380                 case PGC_ENUM:
3381                 {
3382                         struct config_enum *conf = (struct config_enum *) gconf;
3383
3384                         if (conf->assign_hook)
3385                                 if (!(*conf->assign_hook) (conf->boot_val, true,
3386                                                                                    PGC_S_DEFAULT))
3387                                         elog(FATAL, "failed to initialize %s to %s",
3388                                                  conf->gen.name,
3389                                                  config_enum_lookup_by_value(conf, conf->boot_val));
3390                         *conf->variable = conf->reset_val = conf->boot_val;
3391                         break;
3392                 }
3393         }
3394 }
3395
3396
3397 /*
3398  * Select the configuration files and data directory to be used, and
3399  * do the initial read of postgresql.conf.
3400  *
3401  * This is called after processing command-line switches.
3402  *              userDoption is the -D switch value if any (NULL if unspecified).
3403  *              progname is just for use in error messages.
3404  *
3405  * Returns true on success; on failure, prints a suitable error message
3406  * to stderr and returns false.
3407  */
3408 bool
3409 SelectConfigFiles(const char *userDoption, const char *progname)
3410 {
3411         char       *configdir;
3412         char       *fname;
3413         struct stat stat_buf;
3414
3415         /* configdir is -D option, or $PGDATA if no -D */
3416         if (userDoption)
3417                 configdir = make_absolute_path(userDoption);
3418         else
3419                 configdir = make_absolute_path(getenv("PGDATA"));
3420
3421         /*
3422          * Find the configuration file: if config_file was specified on the
3423          * command line, use it, else use configdir/postgresql.conf.  In any case
3424          * ensure the result is an absolute path, so that it will be interpreted
3425          * the same way by future backends.
3426          */
3427         if (ConfigFileName)
3428                 fname = make_absolute_path(ConfigFileName);
3429         else if (configdir)
3430         {
3431                 fname = guc_malloc(FATAL,
3432                                                    strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
3433                 sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
3434         }
3435         else
3436         {
3437                 write_stderr("%s does not know where to find the server configuration file.\n"
3438                                          "You must specify the --config-file or -D invocation "
3439                                          "option or set the PGDATA environment variable.\n",
3440                                          progname);
3441                 return false;
3442         }
3443
3444         /*
3445          * Set the ConfigFileName GUC variable to its final value, ensuring that
3446          * it can't be overridden later.
3447          */
3448         SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3449         free(fname);
3450
3451         /*
3452          * Now read the config file for the first time.
3453          */
3454         if (stat(ConfigFileName, &stat_buf) != 0)
3455         {
3456                 write_stderr("%s cannot access the server configuration file \"%s\": %s\n",
3457                                          progname, ConfigFileName, strerror(errno));
3458                 return false;
3459         }
3460
3461         ProcessConfigFile(PGC_POSTMASTER);
3462
3463         /*
3464          * If the data_directory GUC variable has been set, use that as DataDir;
3465          * otherwise use configdir if set; else punt.
3466          *
3467          * Note: SetDataDir will copy and absolute-ize its argument, so we don't
3468          * have to.
3469          */
3470         if (data_directory)
3471                 SetDataDir(data_directory);
3472         else if (configdir)
3473                 SetDataDir(configdir);
3474         else
3475         {
3476                 write_stderr("%s does not know where to find the database system data.\n"
3477                                          "This can be specified as \"data_directory\" in \"%s\", "
3478                                          "or by the -D invocation option, or by the "
3479                                          "PGDATA environment variable.\n",
3480                                          progname, ConfigFileName);
3481                 return false;
3482         }
3483
3484         /*
3485          * Reflect the final DataDir value back into the data_directory GUC var.
3486          * (If you are wondering why we don't just make them a single variable,
3487          * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
3488          * child backends specially.  XXX is that still true?  Given that we now
3489          * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
3490          * DataDir in advance.)
3491          */
3492         SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
3493
3494         /*
3495          * Figure out where pg_hba.conf is, and make sure the path is absolute.
3496          */
3497         if (HbaFileName)
3498                 fname = make_absolute_path(HbaFileName);
3499         else if (configdir)
3500         {
3501                 fname = guc_malloc(FATAL,
3502                                                    strlen(configdir) + strlen(HBA_FILENAME) + 2);
3503                 sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
3504         }
3505         else
3506         {
3507                 write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
3508                                          "This can be specified as \"hba_file\" in \"%s\", "
3509                                          "or by the -D invocation option, or by the "
3510                                          "PGDATA environment variable.\n",
3511                                          progname, ConfigFileName);
3512                 return false;
3513         }
3514         SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3515         free(fname);
3516
3517         /*
3518          * Likewise for pg_ident.conf.
3519          */
3520         if (IdentFileName)
3521                 fname = make_absolute_path(IdentFileName);
3522         else if (configdir)
3523         {
3524                 fname = guc_malloc(FATAL,
3525                                                    strlen(configdir) + strlen(IDENT_FILENAME) + 2);
3526                 sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
3527         }
3528         else
3529         {
3530                 write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
3531                                          "This can be specified as \"ident_file\" in \"%s\", "
3532                                          "or by the -D invocation option, or by the "
3533                                          "PGDATA environment variable.\n",
3534                                          progname, ConfigFileName);
3535                 return false;
3536         }
3537         SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
3538         free(fname);
3539
3540         free(configdir);
3541
3542         return true;
3543 }
3544
3545
3546 /*
3547  * Reset all options to their saved default values (implements RESET ALL)
3548  */
3549 void
3550 ResetAllOptions(void)
3551 {
3552         int                     i;
3553
3554         for (i = 0; i < num_guc_variables; i++)
3555         {
3556                 struct config_generic *gconf = guc_variables[i];
3557
3558                 /* Don't reset non-SET-able values */
3559                 if (gconf->context != PGC_SUSET &&
3560                         gconf->context != PGC_USERSET)
3561                         continue;
3562                 /* Don't reset if special exclusion from RESET ALL */
3563                 if (gconf->flags & GUC_NO_RESET_ALL)
3564                         continue;
3565                 /* No need to reset if wasn't SET */
3566                 if (gconf->source <= PGC_S_OVERRIDE)
3567                         continue;
3568
3569                 /* Save old value to support transaction abort */
3570                 push_old_value(gconf, GUC_ACTION_SET);
3571
3572                 switch (gconf->vartype)
3573                 {
3574                         case PGC_BOOL:
3575                                 {
3576                                         struct config_bool *conf = (struct config_bool *) gconf;
3577
3578                                         if (conf->assign_hook)
3579                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3580                                                                                                    PGC_S_SESSION))
3581                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3582                                         *conf->variable = conf->reset_val;
3583                                         break;
3584                                 }
3585                         case PGC_INT:
3586                                 {
3587                                         struct config_int *conf = (struct config_int *) gconf;
3588
3589                                         if (conf->assign_hook)
3590                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3591                                                                                                    PGC_S_SESSION))
3592                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3593                                         *conf->variable = conf->reset_val;
3594                                         break;
3595                                 }
3596                         case PGC_REAL:
3597                                 {
3598                                         struct config_real *conf = (struct config_real *) gconf;
3599
3600                                         if (conf->assign_hook)
3601                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3602                                                                                                    PGC_S_SESSION))
3603                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3604                                         *conf->variable = conf->reset_val;
3605                                         break;
3606                                 }
3607                         case PGC_STRING:
3608                                 {
3609                                         struct config_string *conf = (struct config_string *) gconf;
3610                                         char       *str;
3611
3612                                         /* We need not strdup here */
3613                                         str = conf->reset_val;
3614
3615                                         if (conf->assign_hook && str)
3616                                         {
3617                                                 const char *newstr;
3618
3619                                                 newstr = (*conf->assign_hook) (str, true,
3620                                                                                                            PGC_S_SESSION);
3621                                                 if (newstr == NULL)
3622                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3623                                                 else if (newstr != str)
3624                                                 {
3625                                                         /*
3626                                                          * See notes in set_config_option about casting
3627                                                          */
3628                                                         str = (char *) newstr;
3629                                                 }
3630                                         }
3631
3632                                         set_string_field(conf, conf->variable, str);
3633                                         break;
3634                                 }
3635                         case PGC_ENUM:
3636                                 {
3637                                         struct config_enum *conf = (struct config_enum *) gconf;
3638
3639                                         if (conf->assign_hook)
3640                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3641                                                                                                    PGC_S_SESSION))
3642                                                         elog(ERROR, "failed to reset %s", conf->gen.name);
3643                                         *conf->variable = conf->reset_val;
3644                                         break;
3645                                 }
3646                 }
3647
3648                 gconf->source = gconf->reset_source;
3649
3650                 if (gconf->flags & GUC_REPORT)
3651                         ReportGUCOption(gconf);
3652         }
3653 }
3654
3655
3656 /*
3657  * push_old_value
3658  *              Push previous state during transactional assignment to a GUC variable.
3659  */
3660 static void
3661 push_old_value(struct config_generic * gconf, GucAction action)
3662 {
3663         GucStack   *stack;
3664
3665         /* If we're not inside a nest level, do nothing */
3666         if (GUCNestLevel == 0)
3667                 return;
3668
3669         /* Do we already have a stack entry of the current nest level? */
3670         stack = gconf->stack;
3671         if (stack && stack->nest_level >= GUCNestLevel)
3672         {
3673                 /* Yes, so adjust its state if necessary */
3674                 Assert(stack->nest_level == GUCNestLevel);
3675                 switch (action)
3676                 {
3677                         case GUC_ACTION_SET:
3678                                 /* SET overrides any prior action at same nest level */
3679                                 if (stack->state == GUC_SET_LOCAL)
3680                                 {
3681                                         /* must discard old masked value */
3682                                         discard_stack_value(gconf, &stack->masked);
3683                                 }
3684                                 stack->state = GUC_SET;
3685                                 break;
3686                         case GUC_ACTION_LOCAL:
3687                                 if (stack->state == GUC_SET)
3688                                 {
3689                                         /* SET followed by SET LOCAL, remember SET's value */
3690                                         set_stack_value(gconf, &stack->masked);
3691                                         stack->state = GUC_SET_LOCAL;
3692                                 }
3693                                 /* in all other cases, no change to stack entry */
3694                                 break;
3695                         case GUC_ACTION_SAVE:
3696                                 /* Could only have a prior SAVE of same variable */
3697                                 Assert(stack->state == GUC_SAVE);
3698                                 break;
3699                 }
3700                 Assert(guc_dirty);              /* must be set already */
3701                 return;
3702         }
3703
3704         /*
3705          * Push a new stack entry
3706          *
3707          * We keep all the stack entries in TopTransactionContext for simplicity.
3708          */
3709         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3710                                                                                                 sizeof(GucStack));
3711
3712         stack->prev = gconf->stack;
3713         stack->nest_level = GUCNestLevel;
3714         switch (action)
3715         {
3716                 case GUC_ACTION_SET:
3717                         stack->state = GUC_SET;
3718                         break;
3719                 case GUC_ACTION_LOCAL:
3720                         stack->state = GUC_LOCAL;
3721                         break;
3722                 case GUC_ACTION_SAVE:
3723                         stack->state = GUC_SAVE;
3724                         break;
3725         }
3726         stack->source = gconf->source;
3727         set_stack_value(gconf, &stack->prior);
3728
3729         gconf->stack = stack;
3730
3731         /* Ensure we remember to pop at end of xact */
3732         guc_dirty = true;
3733 }
3734
3735
3736 /*
3737  * Do GUC processing at main transaction start.
3738  */
3739 void
3740 AtStart_GUC(void)
3741 {
3742         /*
3743          * The nest level should be 0 between transactions; if it isn't, somebody
3744          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3745          * throw a warning but make no other effort to clean up.
3746          */
3747         if (GUCNestLevel != 0)
3748                 elog(WARNING, "GUC nest level = %d at transaction start",
3749                          GUCNestLevel);
3750         GUCNestLevel = 1;
3751 }
3752
3753 /*
3754  * Enter a new nesting level for GUC values.  This is called at subtransaction
3755  * start and when entering a function that has proconfig settings.      NOTE that
3756  * we must not risk error here, else subtransaction start will be unhappy.
3757  */
3758 int
3759 NewGUCNestLevel(void)
3760 {
3761         return ++GUCNestLevel;
3762 }
3763
3764 /*
3765  * Do GUC processing at transaction or subtransaction commit or abort, or
3766  * when exiting a function that has proconfig settings.  (The name is thus
3767  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3768  * During abort, we discard all GUC settings that were applied at nesting
3769  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3770  */
3771 void
3772 AtEOXact_GUC(bool isCommit, int nestLevel)
3773 {
3774         bool            still_dirty;
3775         int                     i;
3776
3777         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3778
3779         /* Quick exit if nothing's changed in this transaction */
3780         if (!guc_dirty)
3781         {
3782                 GUCNestLevel = nestLevel - 1;
3783                 return;
3784         }
3785
3786         still_dirty = false;
3787         for (i = 0; i < num_guc_variables; i++)
3788         {
3789                 struct config_generic *gconf = guc_variables[i];
3790                 GucStack   *stack;
3791
3792                 /*
3793                  * Process and pop each stack entry within the nest level.      To
3794                  * simplify fmgr_security_definer(), we allow failure exit from a
3795                  * function-with-SET-options to be recovered at the surrounding
3796                  * transaction or subtransaction abort; so there could be more than
3797                  * one stack entry to pop.
3798                  */
3799                 while ((stack = gconf->stack) != NULL &&
3800                            stack->nest_level >= nestLevel)
3801                 {
3802                         GucStack   *prev = stack->prev;
3803                         bool            restorePrior = false;
3804                         bool            restoreMasked = false;
3805                         bool            changed;
3806
3807                         /*
3808                          * In this next bit, if we don't set either restorePrior or
3809                          * restoreMasked, we must "discard" any unwanted fields of the
3810                          * stack entries to avoid leaking memory.  If we do set one of
3811                          * those flags, unused fields will be cleaned up after restoring.
3812                          */
3813                         if (!isCommit)          /* if abort, always restore prior value */
3814                                 restorePrior = true;
3815                         else if (stack->state == GUC_SAVE)
3816                                 restorePrior = true;
3817                         else if (stack->nest_level == 1)
3818                         {
3819                                 /* transaction commit */
3820                                 if (stack->state == GUC_SET_LOCAL)
3821                                         restoreMasked = true;
3822                                 else if (stack->state == GUC_SET)
3823                                 {
3824                                         /* we keep the current active value */
3825                                         discard_stack_value(gconf, &stack->prior);
3826                                 }
3827                                 else    /* must be GUC_LOCAL */
3828                                         restorePrior = true;
3829                         }
3830                         else if (prev == NULL ||
3831                                          prev->nest_level < stack->nest_level - 1)
3832                         {
3833                                 /* decrement entry's level and do not pop it */
3834                                 stack->nest_level--;
3835                                 continue;
3836                         }
3837                         else
3838                         {
3839                                 /*
3840                                  * We have to merge this stack entry into prev. See README for
3841                                  * discussion of this bit.
3842                                  */
3843                                 switch (stack->state)
3844                                 {
3845                                         case GUC_SAVE:
3846                                                 Assert(false);  /* can't get here */
3847
3848                                         case GUC_SET:
3849                                                 /* next level always becomes SET */
3850                                                 discard_stack_value(gconf, &stack->prior);
3851                                                 if (prev->state == GUC_SET_LOCAL)
3852                                                         discard_stack_value(gconf, &prev->masked);
3853                                                 prev->state = GUC_SET;
3854                                                 break;
3855
3856                                         case GUC_LOCAL:
3857                                                 if (prev->state == GUC_SET)
3858                                                 {
3859                                                         /* LOCAL migrates down */
3860                                                         prev->masked = stack->prior;
3861                                                         prev->state = GUC_SET_LOCAL;
3862                                                 }
3863                                                 else
3864                                                 {
3865                                                         /* else just forget this stack level */
3866                                                         discard_stack_value(gconf, &stack->prior);
3867                                                 }
3868                                                 break;
3869
3870                                         case GUC_SET_LOCAL:
3871                                                 /* prior state at this level no longer wanted */
3872                                                 discard_stack_value(gconf, &stack->prior);
3873                                                 /* copy down the masked state */
3874                                                 if (prev->state == GUC_SET_LOCAL)
3875                                                         discard_stack_value(gconf, &prev->masked);
3876                                                 prev->masked = stack->masked;
3877                                                 prev->state = GUC_SET_LOCAL;
3878                                                 break;
3879                                 }
3880                         }
3881
3882                         changed = false;
3883
3884                         if (restorePrior || restoreMasked)
3885                         {
3886                                 /* Perform appropriate restoration of the stacked value */
3887                                 union config_var_value newvalue;
3888                                 GucSource       newsource;
3889
3890                                 if (restoreMasked)
3891                                 {
3892                                         newvalue = stack->masked;
3893                                         newsource = PGC_S_SESSION;
3894                                 }
3895                                 else
3896                                 {
3897                                         newvalue = stack->prior;
3898                                         newsource = stack->source;
3899                                 }
3900
3901                                 switch (gconf->vartype)
3902                                 {
3903                                         case PGC_BOOL:
3904                                                 {
3905                                                         struct config_bool *conf = (struct config_bool *) gconf;
3906                                                         bool            newval = newvalue.boolval;
3907
3908                                                         if (*conf->variable != newval)
3909                                                         {
3910                                                                 if (conf->assign_hook)
3911                                                                         if (!(*conf->assign_hook) (newval,
3912                                                                                                            true, PGC_S_OVERRIDE))
3913                                                                                 elog(LOG, "failed to commit %s",
3914                                                                                          conf->gen.name);
3915                                                                 *conf->variable = newval;
3916                                                                 changed = true;
3917                                                         }
3918                                                         break;
3919                                                 }
3920                                         case PGC_INT:
3921                                                 {
3922                                                         struct config_int *conf = (struct config_int *) gconf;
3923                                                         int                     newval = newvalue.intval;
3924
3925                                                         if (*conf->variable != newval)
3926                                                         {
3927                                                                 if (conf->assign_hook)
3928                                                                         if (!(*conf->assign_hook) (newval,
3929                                                                                                            true, PGC_S_OVERRIDE))
3930                                                                                 elog(LOG, "failed to commit %s",
3931                                                                                          conf->gen.name);
3932                                                                 *conf->variable = newval;
3933                                                                 changed = true;
3934                                                         }
3935                                                         break;
3936                                                 }
3937                                         case PGC_REAL:
3938                                                 {
3939                                                         struct config_real *conf = (struct config_real *) gconf;
3940                                                         double          newval = newvalue.realval;
3941
3942                                                         if (*conf->variable != newval)
3943                                                         {
3944                                                                 if (conf->assign_hook)
3945                                                                         if (!(*conf->assign_hook) (newval,
3946                                                                                                            true, PGC_S_OVERRIDE))
3947                                                                                 elog(LOG, "failed to commit %s",
3948                                                                                          conf->gen.name);
3949                                                                 *conf->variable = newval;
3950                                                                 changed = true;
3951                                                         }
3952                                                         break;
3953                                                 }
3954                                         case PGC_STRING:
3955                                                 {
3956                                                         struct config_string *conf = (struct config_string *) gconf;
3957                                                         char       *newval = newvalue.stringval;
3958
3959                                                         if (*conf->variable != newval)
3960                                                         {
3961                                                                 if (conf->assign_hook && newval)
3962                                                                 {
3963                                                                         const char *newstr;
3964
3965                                                                         newstr = (*conf->assign_hook) (newval, true,
3966                                                                                                                          PGC_S_OVERRIDE);
3967                                                                         if (newstr == NULL)
3968                                                                                 elog(LOG, "failed to commit %s",
3969                                                                                          conf->gen.name);
3970                                                                         else if (newstr != newval)
3971                                                                         {
3972                                                                                 /*
3973                                                                                  * If newval should now be freed,
3974                                                                                  * it'll be taken care of below.
3975                                                                                  *
3976                                                                                  * See notes in set_config_option
3977                                                                                  * about casting
3978                                                                                  */
3979                                                                                 newval = (char *) newstr;
3980                                                                         }
3981                                                                 }
3982
3983                                                                 set_string_field(conf, conf->variable, newval);
3984                                                                 changed = true;
3985                                                         }
3986
3987                                                         /*
3988                                                          * Release stacked values if not used anymore. We
3989                                                          * could use discard_stack_value() here, but since
3990                                                          * we have type-specific code anyway, might as
3991                                                          * well inline it.
3992                                                          */
3993                                                         set_string_field(conf, &stack->prior.stringval, NULL);
3994                                                         set_string_field(conf, &stack->masked.stringval, NULL);
3995                                                         break;
3996                                                 }
3997                                         case PGC_ENUM:
3998                                                 {
3999                                                         struct config_enum *conf = (struct config_enum *) gconf;
4000                                                         int newval = newvalue.enumval;
4001
4002                                                         if (*conf->variable != newval)
4003                                                         {
4004                                                                 if (conf->assign_hook)
4005                                                                         if (!(*conf->assign_hook) (newval,
4006                                                                                                                            true, PGC_S_OVERRIDE))
4007                                                                                 elog(LOG, "failed to commit %s",
4008                                                                                          conf->gen.name);
4009                                                                 *conf->variable = newval;
4010                                                                 changed = true;
4011                                                         }
4012                                                         break;
4013                                                 }
4014                                 }
4015
4016                                 gconf->source = newsource;
4017                         }
4018
4019                         /* Finish popping the state stack */
4020                         gconf->stack = prev;
4021                         pfree(stack);
4022
4023                         /* Report new value if we changed it */
4024                         if (changed && (gconf->flags & GUC_REPORT))
4025                                 ReportGUCOption(gconf);
4026                 }                                               /* end of stack-popping loop */
4027
4028                 if (stack != NULL)
4029                         still_dirty = true;
4030         }
4031
4032         /* If there are no remaining stack entries, we can reset guc_dirty */
4033         guc_dirty = still_dirty;
4034
4035         /* Update nesting level */
4036         GUCNestLevel = nestLevel - 1;
4037 }
4038
4039
4040 /*
4041  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4042  * This is executed at completion of backend startup.
4043  */
4044 void
4045 BeginReportingGUCOptions(void)
4046 {
4047         int                     i;
4048
4049         /*
4050          * Don't do anything unless talking to an interactive frontend of protocol
4051          * 3.0 or later.
4052          */
4053         if (whereToSendOutput != DestRemote ||
4054                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4055                 return;
4056
4057         reporting_enabled = true;
4058
4059         /* Transmit initial values of interesting variables */
4060         for (i = 0; i < num_guc_variables; i++)
4061         {
4062                 struct config_generic *conf = guc_variables[i];
4063
4064                 if (conf->flags & GUC_REPORT)
4065                         ReportGUCOption(conf);
4066         }
4067 }
4068
4069 /*
4070  * ReportGUCOption: if appropriate, transmit option value to frontend
4071  */
4072 static void
4073 ReportGUCOption(struct config_generic * record)
4074 {
4075         if (reporting_enabled && (record->flags & GUC_REPORT))
4076         {
4077                 char       *val = _ShowOption(record, false);
4078                 StringInfoData msgbuf;
4079
4080                 pq_beginmessage(&msgbuf, 'S');
4081                 pq_sendstring(&msgbuf, record->name);
4082                 pq_sendstring(&msgbuf, val);
4083                 pq_endmessage(&msgbuf);
4084
4085                 pfree(val);
4086         }
4087 }
4088
4089
4090 /*
4091  * Try to interpret value as boolean value.  Valid values are: true,
4092  * false, yes, no, on, off, 1, 0; as well as unique prefixes thereof.
4093  * If the string parses okay, return true, else false.
4094  * If okay and result is not NULL, return the value in *result.
4095  */
4096 bool
4097 parse_bool(const char *value, bool *result)
4098 {
4099         size_t          len = strlen(value);
4100
4101         if (pg_strncasecmp(value, "true", len) == 0)
4102         {
4103                 if (result)
4104                         *result = true;
4105         }
4106         else if (pg_strncasecmp(value, "false", len) == 0)
4107         {
4108                 if (result)
4109                         *result = false;
4110         }
4111
4112         else if (pg_strncasecmp(value, "yes", len) == 0)
4113         {
4114                 if (result)
4115                         *result = true;
4116         }
4117         else if (pg_strncasecmp(value, "no", len) == 0)
4118         {
4119                 if (result)
4120                         *result = false;
4121         }
4122
4123         /* 'o' is not unique enough */
4124         else if (pg_strncasecmp(value, "on", (len > 2 ? len : 2)) == 0)
4125         {
4126                 if (result)
4127                         *result = true;
4128         }
4129         else if (pg_strncasecmp(value, "off", (len > 2 ? len : 2)) == 0)
4130         {
4131                 if (result)
4132                         *result = false;
4133         }
4134
4135         else if (pg_strcasecmp(value, "1") == 0)
4136         {
4137                 if (result)
4138                         *result = true;
4139         }
4140         else if (pg_strcasecmp(value, "0") == 0)
4141         {
4142                 if (result)
4143                         *result = false;
4144         }
4145
4146         else
4147         {
4148                 if (result)
4149                         *result = false;        /* suppress compiler warning */
4150                 return false;
4151         }
4152         return true;
4153 }
4154
4155
4156
4157 /*
4158  * Try to parse value as an integer.  The accepted formats are the
4159  * usual decimal, octal, or hexadecimal formats, optionally followed by
4160  * a unit name if "flags" indicates a unit is allowed.
4161  *
4162  * If the string parses okay, return true, else false.
4163  * If okay and result is not NULL, return the value in *result.
4164  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4165  *      HINT message, or NULL if no hint provided.
4166  */
4167 bool
4168 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4169 {
4170         int64           val;
4171         char       *endptr;
4172
4173         /* To suppress compiler warnings, always set output params */
4174         if (result)
4175                 *result = 0;
4176         if (hintmsg)
4177                 *hintmsg = NULL;
4178
4179         /* We assume here that int64 is at least as wide as long */
4180         errno = 0;
4181         val = strtol(value, &endptr, 0);
4182
4183         if (endptr == value)
4184                 return false;                   /* no HINT for integer syntax error */
4185
4186         if (errno == ERANGE || val != (int64) ((int32) val))
4187         {
4188                 if (hintmsg)
4189                         *hintmsg = gettext_noop("Value exceeds integer range.");
4190                 return false;
4191         }
4192
4193         /* allow whitespace between integer and unit */
4194         while (isspace((unsigned char) *endptr))
4195                 endptr++;
4196
4197         /* Handle possible unit */
4198         if (*endptr != '\0')
4199         {
4200                 /*
4201                  * Note: the multiple-switch coding technique here is a bit tedious,
4202                  * but seems necessary to avoid intermediate-value overflows.
4203                  *
4204                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4205                  * overflow due to units conversion, but there are few enough such
4206                  * machines that it does not seem worth trying to be smarter.
4207                  */
4208                 if (flags & GUC_UNIT_MEMORY)
4209                 {
4210                         /* Set hint for use if no match or trailing garbage */
4211                         if (hintmsg)
4212                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4213
4214 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4215 #error BLCKSZ must be between 1KB and 1MB
4216 #endif
4217 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4218 #error XLOG_BLCKSZ must be between 1KB and 1MB
4219 #endif
4220
4221                         if (strncmp(endptr, "kB", 2) == 0)
4222                         {
4223                                 endptr += 2;
4224                                 switch (flags & GUC_UNIT_MEMORY)
4225                                 {
4226                                         case GUC_UNIT_BLOCKS:
4227                                                 val /= (BLCKSZ / 1024);
4228                                                 break;
4229                                         case GUC_UNIT_XBLOCKS:
4230                                                 val /= (XLOG_BLCKSZ / 1024);
4231                                                 break;
4232                                 }
4233                         }
4234                         else if (strncmp(endptr, "MB", 2) == 0)
4235                         {
4236                                 endptr += 2;
4237                                 switch (flags & GUC_UNIT_MEMORY)
4238                                 {
4239                                         case GUC_UNIT_KB:
4240                                                 val *= KB_PER_MB;
4241                                                 break;
4242                                         case GUC_UNIT_BLOCKS:
4243                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4244                                                 break;
4245                                         case GUC_UNIT_XBLOCKS:
4246                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4247                                                 break;
4248                                 }
4249                         }
4250                         else if (strncmp(endptr, "GB", 2) == 0)
4251                         {
4252                                 endptr += 2;
4253                                 switch (flags & GUC_UNIT_MEMORY)
4254                                 {
4255                                         case GUC_UNIT_KB:
4256                                                 val *= KB_PER_GB;
4257                                                 break;
4258                                         case GUC_UNIT_BLOCKS:
4259                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4260                                                 break;
4261                                         case GUC_UNIT_XBLOCKS:
4262                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4263                                                 break;
4264                                 }
4265                         }
4266                 }
4267                 else if (flags & GUC_UNIT_TIME)
4268                 {
4269                         /* Set hint for use if no match or trailing garbage */
4270                         if (hintmsg)
4271                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4272
4273                         if (strncmp(endptr, "ms", 2) == 0)
4274                         {
4275                                 endptr += 2;
4276                                 switch (flags & GUC_UNIT_TIME)
4277                                 {
4278                                         case GUC_UNIT_S:
4279                                                 val /= MS_PER_S;
4280                                                 break;
4281                                         case GUC_UNIT_MIN:
4282                                                 val /= MS_PER_MIN;
4283                                                 break;
4284                                 }
4285                         }
4286                         else if (strncmp(endptr, "s", 1) == 0)
4287                         {
4288                                 endptr += 1;
4289                                 switch (flags & GUC_UNIT_TIME)
4290                                 {
4291                                         case GUC_UNIT_MS:
4292                                                 val *= MS_PER_S;
4293                                                 break;
4294                                         case GUC_UNIT_MIN:
4295                                                 val /= S_PER_MIN;
4296                                                 break;
4297                                 }
4298                         }
4299                         else if (strncmp(endptr, "min", 3) == 0)
4300                         {
4301                                 endptr += 3;
4302                                 switch (flags & GUC_UNIT_TIME)
4303                                 {
4304                                         case GUC_UNIT_MS:
4305                                                 val *= MS_PER_MIN;
4306                                                 break;
4307                                         case GUC_UNIT_S:
4308                                                 val *= S_PER_MIN;
4309                                                 break;
4310                                 }
4311                         }
4312                         else if (strncmp(endptr, "h", 1) == 0)
4313                         {
4314                                 endptr += 1;
4315                                 switch (flags & GUC_UNIT_TIME)
4316                                 {
4317                                         case GUC_UNIT_MS:
4318                                                 val *= MS_PER_H;
4319                                                 break;
4320                                         case GUC_UNIT_S:
4321                                                 val *= S_PER_H;
4322                                                 break;
4323                                         case GUC_UNIT_MIN:
4324                                                 val *= MIN_PER_H;
4325                                                 break;
4326                                 }
4327                         }
4328                         else if (strncmp(endptr, "d", 1) == 0)
4329                         {
4330                                 endptr += 1;
4331                                 switch (flags & GUC_UNIT_TIME)
4332                                 {
4333                                         case GUC_UNIT_MS:
4334                                                 val *= MS_PER_D;
4335                                                 break;
4336                                         case GUC_UNIT_S:
4337                                                 val *= S_PER_D;
4338                                                 break;
4339                                         case GUC_UNIT_MIN:
4340                                                 val *= MIN_PER_D;
4341                                                 break;
4342                                 }
4343                         }
4344                 }
4345
4346                 /* allow whitespace after unit */
4347                 while (isspace((unsigned char) *endptr))
4348                         endptr++;
4349
4350                 if (*endptr != '\0')
4351                         return false;           /* appropriate hint, if any, already set */
4352
4353                 /* Check for overflow due to units conversion */
4354                 if (val != (int64) ((int32) val))
4355                 {
4356                         if (hintmsg)
4357                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4358                         return false;
4359                 }
4360         }
4361
4362         if (result)
4363                 *result = (int) val;
4364         return true;
4365 }
4366
4367
4368
4369 /*
4370  * Try to parse value as a floating point number in the usual format.
4371  * If the string parses okay, return true, else false.
4372  * If okay and result is not NULL, return the value in *result.
4373  */
4374 bool
4375 parse_real(const char *value, double *result)
4376 {
4377         double          val;
4378         char       *endptr;
4379
4380         if (result)
4381                 *result = 0;                    /* suppress compiler warning */
4382
4383         errno = 0;
4384         val = strtod(value, &endptr);
4385         if (endptr == value || errno == ERANGE)
4386                 return false;
4387
4388         /* allow whitespace after number */
4389         while (isspace((unsigned char) *endptr))
4390                 endptr++;
4391         if (*endptr != '\0')
4392                 return false;
4393
4394         if (result)
4395                 *result = val;
4396         return true;
4397 }
4398
4399
4400 /*
4401  * Lookup the name for an enum option with the selected value.
4402  * Should only ever be called with known-valid values, so throws
4403  * an elog(ERROR) if the enum option is not found.
4404  *
4405  * The returned string is a pointer to static data and not
4406  * allocated for modification.
4407  */
4408 const char *
4409 config_enum_lookup_by_value(struct config_enum *record, int val)
4410 {
4411         const struct config_enum_entry *entry;
4412
4413         for (entry = record->options; entry && entry->name; entry++)
4414         {
4415                 if (entry->val == val)
4416                         return entry->name;
4417         }
4418
4419         elog(ERROR, "could not find enum option %d for %s",
4420                  val, record->gen.name);
4421         return NULL;            /* silence compiler */
4422 }
4423
4424
4425 /*
4426  * Lookup the value for an enum option with the selected name
4427  * (case-insensitive).
4428  * If the enum option is found, sets the retval value and returns
4429  * true. If it's not found, return FALSE and retval is set to 0.
4430  */
4431 bool
4432 config_enum_lookup_by_name(struct config_enum *record, const char *value,
4433                                                    int *retval)
4434 {
4435         const struct config_enum_entry *entry;
4436
4437         for (entry = record->options; entry && entry->name; entry++)
4438         {
4439                 if (pg_strcasecmp(value, entry->name) == 0)
4440                 {
4441                         *retval = entry->val;
4442                         return TRUE;
4443                 }
4444         }
4445
4446         *retval = 0;
4447         return FALSE;
4448 }
4449
4450
4451 /*
4452  * Return a list of all available options for an enum, excluding
4453  * hidden ones, separated by the given separator.
4454  * If prefix is non-NULL, it is added before the first enum value.
4455  * If suffix is non-NULL, it is added to the end of the string.
4456  */
4457 static char *
4458 config_enum_get_options(struct config_enum *record, const char *prefix,
4459                                                 const char *suffix, const char *separator)
4460 {
4461         const struct config_enum_entry *entry;
4462         StringInfoData  retstr;
4463         int                     seplen;
4464
4465         initStringInfo(&retstr);
4466         appendStringInfoString(&retstr, prefix);
4467
4468         seplen = strlen(separator);
4469         for (entry = record->options; entry && entry->name; entry++)
4470         {
4471                 if (!entry->hidden)
4472                 {
4473                         appendStringInfoString(&retstr, entry->name);
4474                         appendBinaryStringInfo(&retstr, separator, seplen);
4475                 }
4476         }
4477
4478         /*
4479          * All the entries may have been hidden, leaving the string empty
4480          * if no prefix was given. This indicates a broken GUC setup, since
4481          * there is no use for an enum without any values, so we just check
4482          * to make sure we don't write to invalid memory instead of actually
4483          * trying to do something smart with it.
4484          */
4485         if (retstr.len >= seplen)
4486         {
4487                 /* Replace final separator */
4488                 retstr.data[retstr.len - seplen] = '\0';
4489                 retstr.len -= seplen;
4490         }
4491
4492         appendStringInfoString(&retstr, suffix);
4493
4494         return retstr.data;
4495 }
4496
4497 /*
4498  * Call a GucStringAssignHook function, being careful to free the
4499  * "newval" string if the hook ereports.
4500  *
4501  * This is split out of set_config_option just to avoid the "volatile"
4502  * qualifiers that would otherwise have to be plastered all over.
4503  */
4504 static const char *
4505 call_string_assign_hook(GucStringAssignHook assign_hook,
4506                                                 char *newval, bool doit, GucSource source)
4507 {
4508         const char *result;
4509
4510         PG_TRY();
4511         {
4512                 result = (*assign_hook) (newval, doit, source);
4513         }
4514         PG_CATCH();
4515         {
4516                 free(newval);
4517                 PG_RE_THROW();
4518         }
4519         PG_END_TRY();
4520
4521         return result;
4522 }
4523
4524
4525 /*
4526  * Sets option `name' to given value. The value should be a string
4527  * which is going to be parsed and converted to the appropriate data
4528  * type.  The context and source parameters indicate in which context this
4529  * function is being called so it can apply the access restrictions
4530  * properly.
4531  *
4532  * If value is NULL, set the option to its default value (normally the
4533  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4534  *
4535  * action indicates whether to set the value globally in the session, locally
4536  * to the current top transaction, or just for the duration of a function call.
4537  *
4538  * If changeVal is false then don't really set the option but do all
4539  * the checks to see if it would work.
4540  *
4541  * If there is an error (non-existing option, invalid value) then an
4542  * ereport(ERROR) is thrown *unless* this is called in a context where we
4543  * don't want to ereport (currently, startup or SIGHUP config file reread).
4544  * In that case we write a suitable error message via ereport(LOG) and
4545  * return false. This is working around the deficiencies in the ereport
4546  * mechanism, so don't blame me.  In all other cases, the function
4547  * returns true, including cases where the input is valid but we chose
4548  * not to apply it because of context or source-priority considerations.
4549  *
4550  * See also SetConfigOption for an external interface.
4551  */
4552 bool
4553 set_config_option(const char *name, const char *value,
4554                                   GucContext context, GucSource source,
4555                                   GucAction action, bool changeVal)
4556 {
4557         struct config_generic *record;
4558         int                     elevel;
4559         bool            makeDefault;
4560
4561         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4562         {
4563                 /*
4564                  * To avoid cluttering the log, only the postmaster bleats loudly
4565                  * about problems with the config file.
4566                  */
4567                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4568         }
4569         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4570                 elevel = WARNING;
4571         else
4572                 elevel = ERROR;
4573
4574         record = find_option(name, true, elevel);
4575         if (record == NULL)
4576         {
4577                 ereport(elevel,
4578                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4579                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4580                 return false;
4581         }
4582
4583         /*
4584          * If source is postgresql.conf, mark the found record with
4585          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4586          * that we do it even if changeVal is false, since ProcessConfigFile wants
4587          * the marking to occur during its testing pass.
4588          */
4589         if (source == PGC_S_FILE)
4590                 record->status |= GUC_IS_IN_FILE;
4591
4592         /*
4593          * Check if the option can be set at this time. See guc.h for the precise
4594          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4595          * context. In that case we just ignore the attempt and return true.
4596          */
4597         switch (record->context)
4598         {
4599                 case PGC_INTERNAL:
4600                         if (context == PGC_SIGHUP)
4601                                 return true;
4602                         if (context != PGC_INTERNAL)
4603                         {
4604                                 ereport(elevel,
4605                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4606                                                  errmsg("parameter \"%s\" cannot be changed",
4607                                                                 name)));
4608                                 return false;
4609                         }
4610                         break;
4611                 case PGC_POSTMASTER:
4612                         if (context == PGC_SIGHUP)
4613                         {
4614                                 /*
4615                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4616                                  * We can't change the setting, so give a warning if the DBA
4617                                  * tries to change it.  (Throwing an error would be more
4618                                  * consistent, but seems overly rigid.)
4619                                  */
4620                                 if (changeVal && !is_newvalue_equal(record, value))
4621                                         ereport(elevel,
4622                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4623                                                          errmsg("attempted change of parameter \"%s\" ignored",
4624                                                                         name),
4625                                                          errdetail("This parameter cannot be changed after server start.")));
4626                                 return true;
4627                         }
4628                         if (context != PGC_POSTMASTER)
4629                         {
4630                                 ereport(elevel,
4631                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4632                                                  errmsg("attempted change of parameter \"%s\" ignored",
4633                                                                 name),
4634                                                  errdetail("This parameter cannot be changed after server start.")));
4635                                 return false;
4636                         }
4637                         break;
4638                 case PGC_SIGHUP:
4639                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4640                         {
4641                                 ereport(elevel,
4642                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4643                                                  errmsg("parameter \"%s\" cannot be changed now",
4644                                                                 name)));
4645                                 return false;
4646                         }
4647
4648                         /*
4649                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4650                          * can be changed after postmaster start". But there's nothing
4651                          * that prevents a crafty administrator from sending SIGHUP
4652                          * signals to individual backends only.
4653                          */
4654                         break;
4655                 case PGC_BACKEND:
4656                         if (context == PGC_SIGHUP)
4657                         {
4658                                 /*
4659                                  * If a PGC_BACKEND parameter is changed in the config file,
4660                                  * we want to accept the new value in the postmaster (whence
4661                                  * it will propagate to subsequently-started backends), but
4662                                  * ignore it in existing backends.      This is a tad klugy, but
4663                                  * necessary because we don't re-read the config file during
4664                                  * backend start.
4665                                  */
4666                                 if (IsUnderPostmaster)
4667                                         return true;
4668                         }
4669                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
4670                         {
4671                                 ereport(elevel,
4672                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4673                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4674                                                                 name)));
4675                                 return false;
4676                         }
4677                         break;
4678                 case PGC_SUSET:
4679                         if (context == PGC_USERSET || context == PGC_BACKEND)
4680                         {
4681                                 ereport(elevel,
4682                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4683                                                  errmsg("permission denied to set parameter \"%s\"",
4684                                                                 name)));
4685                                 return false;
4686                         }
4687                         break;
4688                 case PGC_USERSET:
4689                         /* always okay */
4690                         break;
4691         }
4692
4693         /*
4694          * Should we set reset/stacked values?  (If so, the behavior is not
4695          * transactional.)      This is done either when we get a default value from
4696          * the database's/user's/client's default settings or when we reset a
4697          * value to its default.
4698          */
4699         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4700                 ((value != NULL) || source == PGC_S_DEFAULT);
4701
4702         /*
4703          * Ignore attempted set if overridden by previously processed setting.
4704          * However, if changeVal is false then plow ahead anyway since we are
4705          * trying to find out if the value is potentially good, not actually use
4706          * it. Also keep going if makeDefault is true, since we may want to set
4707          * the reset/stacked values even if we can't set the variable itself.
4708          */
4709         if (record->source > source)
4710         {
4711                 if (changeVal && !makeDefault)
4712                 {
4713                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4714                                  name);
4715                         return true;
4716                 }
4717                 changeVal = false;
4718         }
4719
4720         /*
4721          * Evaluate value and set variable.
4722          */
4723         switch (record->vartype)
4724         {
4725                 case PGC_BOOL:
4726                         {
4727                                 struct config_bool *conf = (struct config_bool *) record;
4728                                 bool            newval;
4729
4730                                 if (value)
4731                                 {
4732                                         if (!parse_bool(value, &newval))
4733                                         {
4734                                                 ereport(elevel,
4735                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4736                                                   errmsg("parameter \"%s\" requires a Boolean value",
4737                                                                  name)));
4738                                                 return false;
4739                                         }
4740                                 }
4741                                 else if (source == PGC_S_DEFAULT)
4742                                         newval = conf->boot_val;
4743                                 else
4744                                 {
4745                                         newval = conf->reset_val;
4746                                         source = conf->gen.reset_source;
4747                                 }
4748
4749                                 /* Save old value to support transaction abort */
4750                                 if (changeVal && !makeDefault)
4751                                         push_old_value(&conf->gen, action);
4752
4753                                 if (conf->assign_hook)
4754                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4755                                         {
4756                                                 ereport(elevel,
4757                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4758                                                          errmsg("invalid value for parameter \"%s\": %d",
4759                                                                         name, (int) newval)));
4760                                                 return false;
4761                                         }
4762
4763                                 if (changeVal)
4764                                 {
4765                                         *conf->variable = newval;
4766                                         conf->gen.source = source;
4767                                 }
4768                                 if (makeDefault)
4769                                 {
4770                                         GucStack   *stack;
4771
4772                                         if (conf->gen.reset_source <= source)
4773                                         {
4774                                                 conf->reset_val = newval;
4775                                                 conf->gen.reset_source = source;
4776                                         }
4777                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4778                                         {
4779                                                 if (stack->source <= source)
4780                                                 {
4781                                                         stack->prior.boolval = newval;
4782                                                         stack->source = source;
4783                                                 }
4784                                         }
4785                                 }
4786                                 break;
4787                         }
4788
4789                 case PGC_INT:
4790                         {
4791                                 struct config_int *conf = (struct config_int *) record;
4792                                 int                     newval;
4793
4794                                 if (value)
4795                                 {
4796                                         const char *hintmsg;
4797
4798                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4799                                         {
4800                                                 ereport(elevel,
4801                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4802                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4803                                                                 name, value),
4804                                                                  hintmsg ? errhint("%s", hintmsg) : 0));
4805                                                 return false;
4806                                         }
4807                                         if (newval < conf->min || newval > conf->max)
4808                                         {
4809                                                 ereport(elevel,
4810                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4811                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4812                                                                                 newval, name, conf->min, conf->max)));
4813                                                 return false;
4814                                         }
4815                                 }
4816                                 else if (source == PGC_S_DEFAULT)
4817                                         newval = conf->boot_val;
4818                                 else
4819                                 {
4820                                         newval = conf->reset_val;
4821                                         source = conf->gen.reset_source;
4822                                 }
4823
4824                                 /* Save old value to support transaction abort */
4825                                 if (changeVal && !makeDefault)
4826                                         push_old_value(&conf->gen, action);
4827
4828                                 if (conf->assign_hook)
4829                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4830                                         {
4831                                                 ereport(elevel,
4832                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4833                                                          errmsg("invalid value for parameter \"%s\": %d",
4834                                                                         name, newval)));
4835                                                 return false;
4836                                         }
4837
4838                                 if (changeVal)
4839                                 {
4840                                         *conf->variable = newval;
4841                                         conf->gen.source = source;
4842                                 }
4843                                 if (makeDefault)
4844                                 {
4845                                         GucStack   *stack;
4846
4847                                         if (conf->gen.reset_source <= source)
4848                                         {
4849                                                 conf->reset_val = newval;
4850                                                 conf->gen.reset_source = source;
4851                                         }
4852                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4853                                         {
4854                                                 if (stack->source <= source)
4855                                                 {
4856                                                         stack->prior.intval = newval;
4857                                                         stack->source = source;
4858                                                 }
4859                                         }
4860                                 }
4861                                 break;
4862                         }
4863
4864                 case PGC_REAL:
4865                         {
4866                                 struct config_real *conf = (struct config_real *) record;
4867                                 double          newval;
4868
4869                                 if (value)
4870                                 {
4871                                         if (!parse_real(value, &newval))
4872                                         {
4873                                                 ereport(elevel,
4874                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4875                                                   errmsg("parameter \"%s\" requires a numeric value",
4876                                                                  name)));
4877                                                 return false;
4878                                         }
4879                                         if (newval < conf->min || newval > conf->max)
4880                                         {
4881                                                 ereport(elevel,
4882                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4883                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4884                                                                                 newval, name, conf->min, conf->max)));
4885                                                 return false;
4886                                         }
4887                                 }
4888                                 else if (source == PGC_S_DEFAULT)
4889                                         newval = conf->boot_val;
4890                                 else
4891                                 {
4892                                         newval = conf->reset_val;
4893                                         source = conf->gen.reset_source;
4894                                 }
4895
4896                                 /* Save old value to support transaction abort */
4897                                 if (changeVal && !makeDefault)
4898                                         push_old_value(&conf->gen, action);
4899
4900                                 if (conf->assign_hook)
4901                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4902                                         {
4903                                                 ereport(elevel,
4904                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4905                                                          errmsg("invalid value for parameter \"%s\": %g",
4906                                                                         name, newval)));
4907                                                 return false;
4908                                         }
4909
4910                                 if (changeVal)
4911                                 {
4912                                         *conf->variable = newval;
4913                                         conf->gen.source = source;
4914                                 }
4915                                 if (makeDefault)
4916                                 {
4917                                         GucStack   *stack;
4918
4919                                         if (conf->gen.reset_source <= source)
4920                                         {
4921                                                 conf->reset_val = newval;
4922                                                 conf->gen.reset_source = source;
4923                                         }
4924                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4925                                         {
4926                                                 if (stack->source <= source)
4927                                                 {
4928                                                         stack->prior.realval = newval;
4929                                                         stack->source = source;
4930                                                 }
4931                                         }
4932                                 }
4933                                 break;
4934                         }
4935
4936                 case PGC_STRING:
4937                         {
4938                                 struct config_string *conf = (struct config_string *) record;
4939                                 char       *newval;
4940
4941                                 if (value)
4942                                 {
4943                                         newval = guc_strdup(elevel, value);
4944                                         if (newval == NULL)
4945                                                 return false;
4946
4947                                         /*
4948                                          * The only sort of "parsing" check we need to do is apply
4949                                          * truncation if GUC_IS_NAME.
4950                                          */
4951                                         if (conf->gen.flags & GUC_IS_NAME)
4952                                                 truncate_identifier(newval, strlen(newval), true);
4953                                 }
4954                                 else if (source == PGC_S_DEFAULT)
4955                                 {
4956                                         if (conf->boot_val == NULL)
4957                                                 newval = NULL;
4958                                         else
4959                                         {
4960                                                 newval = guc_strdup(elevel, conf->boot_val);
4961                                                 if (newval == NULL)
4962                                                         return false;
4963                                         }
4964                                 }
4965                                 else
4966                                 {
4967                                         /*
4968                                          * We could possibly avoid strdup here, but easier to make
4969                                          * this case work the same as the normal assignment case;
4970                                          * note the possible free of newval below.
4971                                          */
4972                                         if (conf->reset_val == NULL)
4973                                                 newval = NULL;
4974                                         else
4975                                         {
4976                                                 newval = guc_strdup(elevel, conf->reset_val);
4977                                                 if (newval == NULL)
4978                                                         return false;
4979                                         }
4980                                         source = conf->gen.reset_source;
4981                                 }
4982
4983                                 /* Save old value to support transaction abort */
4984                                 if (changeVal && !makeDefault)
4985                                         push_old_value(&conf->gen, action);
4986
4987                                 if (conf->assign_hook && newval)
4988                                 {
4989                                         const char *hookresult;
4990
4991                                         /*
4992                                          * If the hook ereports, we have to make sure we free
4993                                          * newval, else it will be a permanent memory leak.
4994                                          */
4995                                         hookresult = call_string_assign_hook(conf->assign_hook,
4996                                                                                                                  newval,
4997                                                                                                                  changeVal,
4998                                                                                                                  source);
4999                                         if (hookresult == NULL)
5000                                         {
5001                                                 free(newval);
5002                                                 ereport(elevel,
5003                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5004                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5005                                                                 name, value ? value : "")));
5006                                                 return false;
5007                                         }
5008                                         else if (hookresult != newval)
5009                                         {
5010                                                 free(newval);
5011
5012                                                 /*
5013                                                  * Having to cast away const here is annoying, but the
5014                                                  * alternative is to declare assign_hooks as returning
5015                                                  * char*, which would mean they'd have to cast away
5016                                                  * const, or as both taking and returning char*, which
5017                                                  * doesn't seem attractive either --- we don't want
5018                                                  * them to scribble on the passed str.
5019                                                  */
5020                                                 newval = (char *) hookresult;
5021                                         }
5022                                 }
5023
5024                                 if (changeVal)
5025                                 {
5026                                         set_string_field(conf, conf->variable, newval);
5027                                         conf->gen.source = source;
5028                                 }
5029                                 if (makeDefault)
5030                                 {
5031                                         GucStack   *stack;
5032
5033                                         if (conf->gen.reset_source <= source)
5034                                         {
5035                                                 set_string_field(conf, &conf->reset_val, newval);
5036                                                 conf->gen.reset_source = source;
5037                                         }
5038                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5039                                         {
5040                                                 if (stack->source <= source)
5041                                                 {
5042                                                         set_string_field(conf, &stack->prior.stringval,
5043                                                                                          newval);
5044                                                         stack->source = source;
5045                                                 }
5046                                         }
5047                                 }
5048                                 /* Perhaps we didn't install newval anywhere */
5049                                 if (newval && !string_field_used(conf, newval))
5050                                         free(newval);
5051                                 break;
5052                         }
5053                 case PGC_ENUM:
5054                         {
5055                                 struct config_enum *conf = (struct config_enum *) record;
5056                                 int                     newval;
5057
5058                                 if (value)
5059                                 {
5060                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5061                                         {
5062                                                 char *hintmsg;
5063
5064                                                 hintmsg = config_enum_get_options(conf,
5065                                                                                                                   "Available values: ",
5066                                                                                                                   ".", ", ");
5067
5068                                                 ereport(elevel,
5069                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5070                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5071                                                                                 name, value),
5072                                                                  hintmsg ? errhint("%s", hintmsg) : 0));
5073
5074                                                 if (hintmsg)
5075                                                         pfree(hintmsg);
5076                                                 return false;
5077                                         }
5078                                 }
5079                                 else if (source == PGC_S_DEFAULT)
5080                                         newval = conf->boot_val;
5081                                 else
5082                                 {
5083                                         newval = conf->reset_val;
5084                                         source = conf->gen.reset_source;
5085                                 }
5086
5087                                 /* Save old value to support transaction abort */
5088                                 if (changeVal && !makeDefault)
5089                                         push_old_value(&conf->gen, action);
5090
5091                                 if (conf->assign_hook)
5092                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5093                                         {
5094                                                 ereport(elevel,
5095                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5096                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5097                                                                                 name,
5098                                                                                 config_enum_lookup_by_value(conf, newval))));
5099                                                 return false;
5100                                         }
5101
5102                                 if (changeVal)
5103                                 {
5104                                         *conf->variable = newval;
5105                                         conf->gen.source = source;
5106                                 }
5107                                 if (makeDefault)
5108                                 {
5109                                         GucStack   *stack;
5110
5111                                         if (conf->gen.reset_source <= source)
5112                                         {
5113                                                 conf->reset_val = newval;
5114                                                 conf->gen.reset_source = source;
5115                                         }
5116                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5117                                         {
5118                                                 if (stack->source <= source)
5119                                                 {
5120                                                         stack->prior.enumval = newval;
5121                                                         stack->source = source;
5122                                                 }
5123                                         }
5124                                 }
5125                                 break;
5126                         }
5127         }
5128
5129         if (changeVal && (record->flags & GUC_REPORT))
5130                 ReportGUCOption(record);
5131
5132         return true;
5133 }
5134
5135
5136 /*
5137  * Set the fields for source file and line number the setting came from.
5138  */
5139 static void
5140 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5141 {
5142         struct config_generic *record;
5143         int                     elevel;
5144
5145         /*
5146          * To avoid cluttering the log, only the postmaster bleats loudly
5147          * about problems with the config file.
5148          */
5149         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5150
5151         record = find_option(name, true, elevel);
5152         /* should not happen */
5153         if (record == NULL)
5154                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5155
5156         sourcefile = guc_strdup(elevel, sourcefile);
5157         if (record->sourcefile)
5158                 free(record->sourcefile);
5159         record->sourcefile = sourcefile;
5160         record->sourceline = sourceline;
5161 }
5162
5163 /*
5164  * Set a config option to the given value. See also set_config_option,
5165  * this is just the wrapper to be called from outside GUC.      NB: this
5166  * is used only for non-transactional operations.
5167  *
5168  * Note: there is no support here for setting source file/line, as it
5169  * is currently not needed.
5170  */
5171 void
5172 SetConfigOption(const char *name, const char *value,
5173                                 GucContext context, GucSource source)
5174 {
5175         (void) set_config_option(name, value, context, source,
5176                                                          GUC_ACTION_SET, true);
5177 }
5178
5179
5180
5181 /*
5182  * Fetch the current value of the option `name'. If the option doesn't exist,
5183  * throw an ereport and don't return.
5184  *
5185  * The string is *not* allocated for modification and is really only
5186  * valid until the next call to configuration related functions.
5187  */
5188 const char *
5189 GetConfigOption(const char *name)
5190 {
5191         struct config_generic *record;
5192         static char buffer[256];
5193
5194         record = find_option(name, false, ERROR);
5195         if (record == NULL)
5196                 ereport(ERROR,
5197                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5198                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5199         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5200                 ereport(ERROR,
5201                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5202                                  errmsg("must be superuser to examine \"%s\"", name)));
5203
5204         switch (record->vartype)
5205         {
5206                 case PGC_BOOL:
5207                         return *((struct config_bool *) record)->variable ? "on" : "off";
5208
5209                 case PGC_INT:
5210                         snprintf(buffer, sizeof(buffer), "%d",
5211                                          *((struct config_int *) record)->variable);
5212                         return buffer;
5213
5214                 case PGC_REAL:
5215                         snprintf(buffer, sizeof(buffer), "%g",
5216                                          *((struct config_real *) record)->variable);
5217                         return buffer;
5218
5219                 case PGC_STRING:
5220                         return *((struct config_string *) record)->variable;
5221
5222                 case PGC_ENUM:
5223                         return config_enum_lookup_by_value((struct config_enum *) record,
5224                                                                                         *((struct config_enum *) record)->variable);
5225         }
5226         return NULL;
5227 }
5228
5229 /*
5230  * Get the RESET value associated with the given option.
5231  *
5232  * Note: this is not re-entrant, due to use of static result buffer;
5233  * not to mention that a string variable could have its reset_val changed.
5234  * Beware of assuming the result value is good for very long.
5235  */
5236 const char *
5237 GetConfigOptionResetString(const char *name)
5238 {
5239         struct config_generic *record;
5240         static char buffer[256];
5241
5242         record = find_option(name, false, ERROR);
5243         if (record == NULL)
5244                 ereport(ERROR,
5245                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5246                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5247         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5248                 ereport(ERROR,
5249                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5250                                  errmsg("must be superuser to examine \"%s\"", name)));
5251
5252         switch (record->vartype)
5253         {
5254                 case PGC_BOOL:
5255                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5256
5257                 case PGC_INT:
5258                         snprintf(buffer, sizeof(buffer), "%d",
5259                                          ((struct config_int *) record)->reset_val);
5260                         return buffer;
5261
5262                 case PGC_REAL:
5263                         snprintf(buffer, sizeof(buffer), "%g",
5264                                          ((struct config_real *) record)->reset_val);
5265                         return buffer;
5266
5267                 case PGC_STRING:
5268                         return ((struct config_string *) record)->reset_val;
5269
5270                 case PGC_ENUM:
5271                         return config_enum_lookup_by_value((struct config_enum *) record,
5272                                                                                     ((struct config_enum *) record)->reset_val);
5273         }
5274         return NULL;
5275 }
5276
5277 /*
5278  * Detect whether the given configuration option can only be set by
5279  * a superuser.
5280  */
5281 bool
5282 IsSuperuserConfigOption(const char *name)
5283 {
5284         struct config_generic *record;
5285
5286         record = find_option(name, false, ERROR);
5287         /* On an unrecognized name, don't error, just return false. */
5288         if (record == NULL)
5289                 return false;
5290         return (record->context == PGC_SUSET);
5291 }
5292
5293
5294 /*
5295  * GUC_complaint_elevel
5296  *              Get the ereport error level to use in an assign_hook's error report.
5297  *
5298  * This should be used by assign hooks that want to emit a custom error
5299  * report (in addition to the generic "invalid value for option FOO" that
5300  * guc.c will provide).  Note that the result might be ERROR or a lower
5301  * level, so the caller must be prepared for control to return from ereport,
5302  * or not.  If control does return, return false/NULL from the hook function.
5303  *
5304  * At some point it'd be nice to replace this with a mechanism that allows
5305  * the custom message to become the DETAIL line of guc.c's generic message.
5306  */
5307 int
5308 GUC_complaint_elevel(GucSource source)
5309 {
5310         int                     elevel;
5311
5312         if (source == PGC_S_FILE)
5313         {
5314                 /*
5315                  * To avoid cluttering the log, only the postmaster bleats loudly
5316                  * about problems with the config file.
5317                  */
5318                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5319         }
5320         else if (source == PGC_S_OVERRIDE)
5321         {
5322                 /*
5323                  * If we're a postmaster child, this is probably "undo" during
5324                  * transaction abort, so we don't want to clutter the log.  There's
5325                  * a small chance of a real problem with an OVERRIDE setting,
5326                  * though, so suppressing the message entirely wouldn't be desirable.
5327                  */
5328                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5329         }
5330         else if (source < PGC_S_INTERACTIVE)
5331                 elevel = LOG;
5332         else
5333                 elevel = ERROR;
5334
5335         return elevel;
5336 }
5337
5338
5339 /*
5340  * flatten_set_variable_args
5341  *              Given a parsenode List as emitted by the grammar for SET,
5342  *              convert to the flat string representation used by GUC.
5343  *
5344  * We need to be told the name of the variable the args are for, because
5345  * the flattening rules vary (ugh).
5346  *
5347  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5348  * a palloc'd string.
5349  */
5350 static char *
5351 flatten_set_variable_args(const char *name, List *args)
5352 {
5353         struct config_generic *record;
5354         int                     flags;
5355         StringInfoData buf;
5356         ListCell   *l;
5357
5358         /* Fast path if just DEFAULT */
5359         if (args == NIL)
5360                 return NULL;
5361
5362         /* Else get flags for the variable */
5363         record = find_option(name, true, ERROR);
5364         if (record == NULL)
5365                 ereport(ERROR,
5366                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5367                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5368
5369         flags = record->flags;
5370
5371         /* Complain if list input and non-list variable */
5372         if ((flags & GUC_LIST_INPUT) == 0 &&
5373                 list_length(args) != 1)
5374                 ereport(ERROR,
5375                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5376                                  errmsg("SET %s takes only one argument", name)));
5377
5378         initStringInfo(&buf);
5379
5380         /*
5381          * Each list member may be a plain A_Const node, or an A_Const within a
5382          * TypeCast; the latter case is supported only for ConstInterval
5383          * arguments (for SET TIME ZONE).
5384          */
5385         foreach(l, args)
5386         {
5387                 Node       *arg = (Node *) lfirst(l);
5388                 char       *val;
5389                 TypeName   *typename = NULL;
5390                 A_Const    *con;
5391
5392                 if (l != list_head(args))
5393                         appendStringInfo(&buf, ", ");
5394
5395                 if (IsA(arg, TypeCast))
5396                 {
5397                         TypeCast *tc = (TypeCast *) arg;
5398
5399                         arg = tc->arg;
5400                         typename = tc->typename;
5401                 }
5402
5403                 if (!IsA(arg, A_Const))
5404                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5405                 con = (A_Const *) arg;
5406
5407                 switch (nodeTag(&con->val))
5408                 {
5409                         case T_Integer:
5410                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5411                                 break;
5412                         case T_Float:
5413                                 /* represented as a string, so just copy it */
5414                                 appendStringInfoString(&buf, strVal(&con->val));
5415                                 break;
5416                         case T_String:
5417                                 val = strVal(&con->val);
5418                                 if (typename != NULL)
5419                                 {
5420                                         /*
5421                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5422                                          * to interval and back to normalize the value and account
5423                                          * for any typmod.
5424                                          */
5425                                         Oid                     typoid;
5426                                         int32           typmod;
5427                                         Datum           interval;
5428                                         char       *intervalout;
5429
5430                                         typoid = typenameTypeId(NULL, typename, &typmod);
5431                                         Assert(typoid == INTERVALOID);
5432
5433                                         interval =
5434                                                 DirectFunctionCall3(interval_in,
5435                                                                                         CStringGetDatum(val),
5436                                                                                         ObjectIdGetDatum(InvalidOid),
5437                                                                                         Int32GetDatum(typmod));
5438
5439                                         intervalout =
5440                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5441                                                                                                                         interval));
5442                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5443                                 }
5444                                 else
5445                                 {
5446                                         /*
5447                                          * Plain string literal or identifier.  For quote mode,
5448                                          * quote it if it's not a vanilla identifier.
5449                                          */
5450                                         if (flags & GUC_LIST_QUOTE)
5451                                                 appendStringInfoString(&buf, quote_identifier(val));
5452                                         else
5453                                                 appendStringInfoString(&buf, val);
5454                                 }
5455                                 break;
5456                         default:
5457                                 elog(ERROR, "unrecognized node type: %d",
5458                                          (int) nodeTag(&con->val));
5459                                 break;
5460                 }
5461         }
5462
5463         return buf.data;
5464 }
5465
5466
5467 /*
5468  * SET command
5469  */
5470 void
5471 ExecSetVariableStmt(VariableSetStmt *stmt)
5472 {
5473         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5474
5475         switch (stmt->kind)
5476         {
5477                 case VAR_SET_VALUE:
5478                 case VAR_SET_CURRENT:
5479                         set_config_option(stmt->name,
5480                                                           ExtractSetVariableArgs(stmt),
5481                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5482                                                           PGC_S_SESSION,
5483                                                           action,
5484                                                           true);
5485                         break;
5486                 case VAR_SET_MULTI:
5487
5488                         /*
5489                          * Special case for special SQL syntax that effectively sets more
5490                          * than one variable per statement.
5491                          */
5492                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5493                         {
5494                                 ListCell   *head;
5495
5496                                 foreach(head, stmt->args)
5497                                 {
5498                                         DefElem    *item = (DefElem *) lfirst(head);
5499
5500                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5501                                                 SetPGVariable("transaction_isolation",
5502                                                                           list_make1(item->arg), stmt->is_local);
5503                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5504                                                 SetPGVariable("transaction_read_only",
5505                                                                           list_make1(item->arg), stmt->is_local);
5506                                         else
5507                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5508                                                          item->defname);
5509                                 }
5510                         }
5511                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5512                         {
5513                                 ListCell   *head;
5514
5515                                 foreach(head, stmt->args)
5516                                 {
5517                                         DefElem    *item = (DefElem *) lfirst(head);
5518
5519                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5520                                                 SetPGVariable("default_transaction_isolation",
5521                                                                           list_make1(item->arg), stmt->is_local);
5522                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5523                                                 SetPGVariable("default_transaction_read_only",
5524                                                                           list_make1(item->arg), stmt->is_local);
5525                                         else
5526                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5527                                                          item->defname);
5528                                 }
5529                         }
5530                         else
5531                                 elog(ERROR, "unexpected SET MULTI element: %s",
5532                                          stmt->name);
5533                         break;
5534                 case VAR_SET_DEFAULT:
5535                 case VAR_RESET:
5536                         set_config_option(stmt->name,
5537                                                           NULL,
5538                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5539                                                           PGC_S_SESSION,
5540                                                           action,
5541                                                           true);
5542                         break;
5543                 case VAR_RESET_ALL:
5544                         ResetAllOptions();
5545                         break;
5546         }
5547 }
5548
5549 /*
5550  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5551  * The result is palloc'd.
5552  *
5553  * This is exported for use by actions such as ALTER ROLE SET.
5554  */
5555 char *
5556 ExtractSetVariableArgs(VariableSetStmt *stmt)
5557 {
5558         switch (stmt->kind)
5559         {
5560                 case VAR_SET_VALUE:
5561                         return flatten_set_variable_args(stmt->name, stmt->args);
5562                 case VAR_SET_CURRENT:
5563                         return GetConfigOptionByName(stmt->name, NULL);
5564                 default:
5565                         return NULL;
5566         }
5567 }
5568
5569 /*
5570  * SetPGVariable - SET command exported as an easily-C-callable function.
5571  *
5572  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5573  * by passing args == NIL), but not SET FROM CURRENT functionality.
5574  */
5575 void
5576 SetPGVariable(const char *name, List *args, bool is_local)
5577 {
5578         char       *argstring = flatten_set_variable_args(name, args);
5579
5580         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5581         set_config_option(name,
5582                                           argstring,
5583                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5584                                           PGC_S_SESSION,
5585                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5586                                           true);
5587 }
5588
5589 /*
5590  * SET command wrapped as a SQL callable function.
5591  */
5592 Datum
5593 set_config_by_name(PG_FUNCTION_ARGS)
5594 {
5595         char       *name;
5596         char       *value;
5597         char       *new_value;
5598         bool            is_local;
5599
5600         if (PG_ARGISNULL(0))
5601                 ereport(ERROR,
5602                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5603                                  errmsg("SET requires parameter name")));
5604
5605         /* Get the GUC variable name */
5606         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5607
5608         /* Get the desired value or set to NULL for a reset request */
5609         if (PG_ARGISNULL(1))
5610                 value = NULL;
5611         else
5612                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5613
5614         /*
5615          * Get the desired state of is_local. Default to false if provided value
5616          * is NULL
5617          */
5618         if (PG_ARGISNULL(2))
5619                 is_local = false;
5620         else
5621                 is_local = PG_GETARG_BOOL(2);
5622
5623         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5624         set_config_option(name,
5625                                           value,
5626                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5627                                           PGC_S_SESSION,
5628                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5629                                           true);
5630
5631         /* get the new current value */
5632         new_value = GetConfigOptionByName(name, NULL);
5633
5634         /* Convert return string to text */
5635         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5636 }
5637
5638
5639 /*
5640  * Common code for DefineCustomXXXVariable subroutines: allocate the
5641  * new variable's config struct and fill in generic fields.
5642  */
5643 static struct config_generic *
5644 init_custom_variable(const char *name,
5645                                          const char *short_desc,
5646                                          const char *long_desc,
5647                                          GucContext context,
5648                                          int flags,
5649                                          enum config_type type,
5650                                          size_t sz)
5651 {
5652         struct config_generic *gen;
5653
5654         /*
5655          * Only allow custom PGC_POSTMASTER variables to be created during
5656          * shared library preload; any later than that, we can't ensure that
5657          * the value doesn't change after startup.  This is a fatal elog if it
5658          * happens; just erroring out isn't safe because we don't know what
5659          * the calling loadable module might already have hooked into.
5660          */
5661         if (context == PGC_POSTMASTER &&
5662                 !process_shared_preload_libraries_in_progress)
5663                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5664
5665         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5666         memset(gen, 0, sz);
5667
5668         gen->name = guc_strdup(ERROR, name);
5669         gen->context = context;
5670         gen->group = CUSTOM_OPTIONS;
5671         gen->short_desc = short_desc;
5672         gen->long_desc = long_desc;
5673         gen->flags = flags;
5674         gen->vartype = type;
5675
5676         return gen;
5677 }
5678
5679 /*
5680  * Common code for DefineCustomXXXVariable subroutines: insert the new
5681  * variable into the GUC variable array, replacing any placeholder.
5682  */
5683 static void
5684 define_custom_variable(struct config_generic * variable)
5685 {
5686         const char *name = variable->name;
5687         const char **nameAddr = &name;
5688         const char *value;
5689         struct config_string *pHolder;
5690         GucContext phcontext;
5691         struct config_generic **res;
5692
5693         /*
5694          * See if there's a placeholder by the same name.
5695          */
5696         res = (struct config_generic **) bsearch((void *) &nameAddr,
5697                                                                                          (void *) guc_variables,
5698                                                                                          num_guc_variables,
5699                                                                                          sizeof(struct config_generic *),
5700                                                                                          guc_var_compare);
5701         if (res == NULL)
5702         {
5703                 /*
5704                  * No placeholder to replace, so we can just add it ... but first,
5705                  * make sure it's initialized to its default value.
5706                  */
5707                 InitializeOneGUCOption(variable);
5708                 add_guc_variable(variable, ERROR);
5709                 return;
5710         }
5711
5712         /*
5713          * This better be a placeholder
5714          */
5715         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5716                 ereport(ERROR,
5717                                 (errcode(ERRCODE_INTERNAL_ERROR),
5718                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5719
5720         Assert((*res)->vartype == PGC_STRING);
5721         pHolder = (struct config_string *) (*res);
5722
5723         /*
5724          * First, set the variable to its default value.  We must do this even
5725          * though we intend to immediately apply a new value, since it's possible
5726          * that the new value is invalid.
5727          */
5728         InitializeOneGUCOption(variable);
5729
5730         /*
5731          * Replace the placeholder. We aren't changing the name, so no re-sorting
5732          * is necessary
5733          */
5734         *res = variable;
5735
5736         /*
5737          * Infer context for assignment based on source of existing value.
5738          * We can't tell this with exact accuracy, but we can at least do
5739          * something reasonable in typical cases.
5740          */
5741         switch (pHolder->gen.source)
5742         {
5743                 case PGC_S_DEFAULT:
5744                 case PGC_S_ENV_VAR:
5745                 case PGC_S_FILE:
5746                 case PGC_S_ARGV:
5747                         /*
5748                          * If we got past the check in init_custom_variable, we can
5749                          * safely assume that any existing value for a PGC_POSTMASTER
5750                          * variable was set in postmaster context.
5751                          */
5752                         if (variable->context == PGC_POSTMASTER)
5753                                 phcontext = PGC_POSTMASTER;
5754                         else
5755                                 phcontext = PGC_SIGHUP;
5756                         break;
5757                 case PGC_S_DATABASE:
5758                 case PGC_S_USER:
5759                 case PGC_S_CLIENT:
5760                 case PGC_S_SESSION:
5761                 default:
5762                         phcontext = PGC_USERSET;
5763                         break;
5764         }
5765
5766         /*
5767          * Assign the string value stored in the placeholder to the real variable.
5768          *
5769          * XXX this is not really good enough --- it should be a nontransactional
5770          * assignment, since we don't want it to roll back if the current xact
5771          * fails later.  (Or do we?)
5772          */
5773         value = *pHolder->variable;
5774
5775         if (value)
5776         {
5777                 if (set_config_option(name, value,
5778                                                           phcontext, pHolder->gen.source,
5779                                                           GUC_ACTION_SET, true))
5780                 {
5781                         /* Also copy over any saved source-location information */
5782                         if (pHolder->gen.sourcefile)
5783                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5784                                                                           pHolder->gen.sourceline);
5785                 }
5786         }
5787
5788         /*
5789          * Free up as much as we conveniently can of the placeholder structure
5790          * (this neglects any stack items...)
5791          */
5792         set_string_field(pHolder, pHolder->variable, NULL);
5793         set_string_field(pHolder, &pHolder->reset_val, NULL);
5794
5795         free(pHolder);
5796 }
5797
5798 void
5799 DefineCustomBoolVariable(const char *name,
5800                                                  const char *short_desc,
5801                                                  const char *long_desc,
5802                                                  bool *valueAddr,
5803                                                  bool bootValue,
5804                                                  GucContext context,
5805                                                  int flags,
5806                                                  GucBoolAssignHook assign_hook,
5807                                                  GucShowHook show_hook)
5808 {
5809         struct config_bool *var;
5810
5811         var = (struct config_bool *)
5812                 init_custom_variable(name, short_desc, long_desc, context, flags,
5813                                                          PGC_BOOL, sizeof(struct config_bool));
5814         var->variable = valueAddr;
5815         var->boot_val = bootValue;
5816         var->reset_val = bootValue;
5817         var->assign_hook = assign_hook;
5818         var->show_hook = show_hook;
5819         define_custom_variable(&var->gen);
5820 }
5821
5822 void
5823 DefineCustomIntVariable(const char *name,
5824                                                 const char *short_desc,
5825                                                 const char *long_desc,
5826                                                 int *valueAddr,
5827                                                 int bootValue,
5828                                                 int minValue,
5829                                                 int maxValue,
5830                                                 GucContext context,
5831                                                 int flags,
5832                                                 GucIntAssignHook assign_hook,
5833                                                 GucShowHook show_hook)
5834 {
5835         struct config_int *var;
5836
5837         var = (struct config_int *)
5838                 init_custom_variable(name, short_desc, long_desc, context, flags,
5839                                                          PGC_INT, sizeof(struct config_int));
5840         var->variable = valueAddr;
5841         var->boot_val = bootValue;
5842         var->reset_val = bootValue;
5843         var->min = minValue;
5844         var->max = maxValue;
5845         var->assign_hook = assign_hook;
5846         var->show_hook = show_hook;
5847         define_custom_variable(&var->gen);
5848 }
5849
5850 void
5851 DefineCustomRealVariable(const char *name,
5852                                                  const char *short_desc,
5853                                                  const char *long_desc,
5854                                                  double *valueAddr,
5855                                                  double bootValue,
5856                                                  double minValue,
5857                                                  double maxValue,
5858                                                  GucContext context,
5859                                                  int flags,
5860                                                  GucRealAssignHook assign_hook,
5861                                                  GucShowHook show_hook)
5862 {
5863         struct config_real *var;
5864
5865         var = (struct config_real *)
5866                 init_custom_variable(name, short_desc, long_desc, context, flags,
5867                                                          PGC_REAL, sizeof(struct config_real));
5868         var->variable = valueAddr;
5869         var->boot_val = bootValue;
5870         var->reset_val = bootValue;
5871         var->min = minValue;
5872         var->max = maxValue;
5873         var->assign_hook = assign_hook;
5874         var->show_hook = show_hook;
5875         define_custom_variable(&var->gen);
5876 }
5877
5878 void
5879 DefineCustomStringVariable(const char *name,
5880                                                    const char *short_desc,
5881                                                    const char *long_desc,
5882                                                    char **valueAddr,
5883                                                    const char *bootValue,
5884                                                    GucContext context,
5885                                                    int flags,
5886                                                    GucStringAssignHook assign_hook,
5887                                                    GucShowHook show_hook)
5888 {
5889         struct config_string *var;
5890
5891         var = (struct config_string *)
5892                 init_custom_variable(name, short_desc, long_desc, context, flags,
5893                                                          PGC_STRING, sizeof(struct config_string));
5894         var->variable = valueAddr;
5895         var->boot_val = bootValue;
5896         /* we could probably do without strdup, but keep it like normal case */
5897         if (var->boot_val)
5898                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5899         var->assign_hook = assign_hook;
5900         var->show_hook = show_hook;
5901         define_custom_variable(&var->gen);
5902 }
5903
5904 void
5905 DefineCustomEnumVariable(const char *name,
5906                                                  const char *short_desc,
5907                                                  const char *long_desc,
5908                                                  int *valueAddr,
5909                                                  int bootValue,
5910                                                  const struct config_enum_entry *options,
5911                                                  GucContext context,
5912                                                  int flags,
5913                                                  GucEnumAssignHook assign_hook,
5914                                                  GucShowHook show_hook)
5915 {
5916         struct config_enum *var;
5917
5918         var = (struct config_enum *)
5919                 init_custom_variable(name, short_desc, long_desc, context, flags,
5920                                                          PGC_ENUM, sizeof(struct config_enum));
5921         var->variable = valueAddr;
5922         var->boot_val = bootValue;
5923         var->reset_val = bootValue;
5924         var->options = options;
5925         var->assign_hook = assign_hook;
5926         var->show_hook = show_hook;
5927         define_custom_variable(&var->gen);
5928 }
5929
5930 void
5931 EmitWarningsOnPlaceholders(const char *className)
5932 {
5933         int                     classLen = strlen(className);
5934         int                     i;
5935
5936         for (i = 0; i < num_guc_variables; i++)
5937         {
5938                 struct config_generic *var = guc_variables[i];
5939
5940                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5941                         strncmp(className, var->name, classLen) == 0 &&
5942                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5943                 {
5944                         ereport(WARNING,
5945                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5946                                          errmsg("unrecognized configuration parameter \"%s\"",
5947                                                         var->name)));
5948                 }
5949         }
5950 }
5951
5952
5953 /*
5954  * SHOW command
5955  */
5956 void
5957 GetPGVariable(const char *name, DestReceiver *dest)
5958 {
5959         if (guc_name_compare(name, "all") == 0)
5960                 ShowAllGUCConfig(dest);
5961         else
5962                 ShowGUCConfigOption(name, dest);
5963 }
5964
5965 TupleDesc
5966 GetPGVariableResultDesc(const char *name)
5967 {
5968         TupleDesc       tupdesc;
5969
5970         if (guc_name_compare(name, "all") == 0)
5971         {
5972                 /* need a tuple descriptor representing three TEXT columns */
5973                 tupdesc = CreateTemplateTupleDesc(3, false);
5974                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5975                                                    TEXTOID, -1, 0);
5976                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5977                                                    TEXTOID, -1, 0);
5978                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5979                                                    TEXTOID, -1, 0);
5980         }
5981         else
5982         {
5983                 const char *varname;
5984
5985                 /* Get the canonical spelling of name */
5986                 (void) GetConfigOptionByName(name, &varname);
5987
5988                 /* need a tuple descriptor representing a single TEXT column */
5989                 tupdesc = CreateTemplateTupleDesc(1, false);
5990                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5991                                                    TEXTOID, -1, 0);
5992         }
5993         return tupdesc;
5994 }
5995
5996
5997 /*
5998  * SHOW command
5999  */
6000 static void
6001 ShowGUCConfigOption(const char *name, DestReceiver *dest)
6002 {
6003         TupOutputState *tstate;
6004         TupleDesc       tupdesc;
6005         const char *varname;
6006         char       *value;
6007
6008         /* Get the value and canonical spelling of name */
6009         value = GetConfigOptionByName(name, &varname);
6010
6011         /* need a tuple descriptor representing a single TEXT column */
6012         tupdesc = CreateTemplateTupleDesc(1, false);
6013         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
6014                                            TEXTOID, -1, 0);
6015
6016         /* prepare for projection of tuples */
6017         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6018
6019         /* Send it */
6020         do_text_output_oneline(tstate, value);
6021
6022         end_tup_output(tstate);
6023 }
6024
6025 /*
6026  * SHOW ALL command
6027  */
6028 static void
6029 ShowAllGUCConfig(DestReceiver *dest)
6030 {
6031         bool            am_superuser = superuser();
6032         int                     i;
6033         TupOutputState *tstate;
6034         TupleDesc       tupdesc;
6035         char       *values[3];
6036
6037         /* need a tuple descriptor representing three TEXT columns */
6038         tupdesc = CreateTemplateTupleDesc(3, false);
6039         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6040                                            TEXTOID, -1, 0);
6041         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6042                                            TEXTOID, -1, 0);
6043         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
6044                                            TEXTOID, -1, 0);
6045
6046
6047         /* prepare for projection of tuples */
6048         tstate = begin_tup_output_tupdesc(dest, tupdesc);
6049
6050         for (i = 0; i < num_guc_variables; i++)
6051         {
6052                 struct config_generic *conf = guc_variables[i];
6053
6054                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6055                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
6056                         continue;
6057
6058                 /* assign to the values array */
6059                 values[0] = (char *) conf->name;
6060                 values[1] = _ShowOption(conf, true);
6061                 values[2] = (char *) conf->short_desc;
6062
6063                 /* send it to dest */
6064                 do_tup_output(tstate, values);
6065
6066                 /* clean up */
6067                 if (values[1] != NULL)
6068                         pfree(values[1]);
6069         }
6070
6071         end_tup_output(tstate);
6072 }
6073
6074 /*
6075  * Return GUC variable value by name; optionally return canonical
6076  * form of name.  Return value is palloc'd.
6077  */
6078 char *
6079 GetConfigOptionByName(const char *name, const char **varname)
6080 {
6081         struct config_generic *record;
6082
6083         record = find_option(name, false, ERROR);
6084         if (record == NULL)
6085                 ereport(ERROR,
6086                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6087                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6088         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6089                 ereport(ERROR,
6090                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6091                                  errmsg("must be superuser to examine \"%s\"", name)));
6092
6093         if (varname)
6094                 *varname = record->name;
6095
6096         return _ShowOption(record, true);
6097 }
6098
6099 /*
6100  * Return GUC variable value by variable number; optionally return canonical
6101  * form of name.  Return value is palloc'd.
6102  */
6103 void
6104 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6105 {
6106         char            buffer[256];
6107         struct config_generic *conf;
6108
6109         /* check requested variable number valid */
6110         Assert((varnum >= 0) && (varnum < num_guc_variables));
6111
6112         conf = guc_variables[varnum];
6113
6114         if (noshow)
6115         {
6116                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6117                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6118                         *noshow = true;
6119                 else
6120                         *noshow = false;
6121         }
6122
6123         /* first get the generic attributes */
6124
6125         /* name */
6126         values[0] = conf->name;
6127
6128         /* setting : use _ShowOption in order to avoid duplicating the logic */
6129         values[1] = _ShowOption(conf, false);
6130
6131         /* unit */
6132         if (conf->vartype == PGC_INT)
6133         {
6134                 static char buf[8];
6135
6136                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6137                 {
6138                         case GUC_UNIT_KB:
6139                                 values[2] = "kB";
6140                                 break;
6141                         case GUC_UNIT_BLOCKS:
6142                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6143                                 values[2] = buf;
6144                                 break;
6145                         case GUC_UNIT_XBLOCKS:
6146                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6147                                 values[2] = buf;
6148                                 break;
6149                         case GUC_UNIT_MS:
6150                                 values[2] = "ms";
6151                                 break;
6152                         case GUC_UNIT_S:
6153                                 values[2] = "s";
6154                                 break;
6155                         case GUC_UNIT_MIN:
6156                                 values[2] = "min";
6157                                 break;
6158                         default:
6159                                 values[2] = "";
6160                                 break;
6161                 }
6162         }
6163         else
6164                 values[2] = NULL;
6165
6166         /* group */
6167         values[3] = config_group_names[conf->group];
6168
6169         /* short_desc */
6170         values[4] = conf->short_desc;
6171
6172         /* extra_desc */
6173         values[5] = conf->long_desc;
6174
6175         /* context */
6176         values[6] = GucContext_Names[conf->context];
6177
6178         /* vartype */
6179         values[7] = config_type_names[conf->vartype];
6180
6181         /* source */
6182         values[8] = GucSource_Names[conf->source];
6183
6184         /* now get the type specifc attributes */
6185         switch (conf->vartype)
6186         {
6187                 case PGC_BOOL:
6188                         {
6189                                 struct config_bool *lconf = (struct config_bool *) conf;
6190
6191                                 /* min_val */
6192                                 values[9] = NULL;
6193
6194                                 /* max_val */
6195                                 values[10] = NULL;
6196
6197                                 /* enumvals */
6198                                 values[11] = NULL;
6199
6200                                 /* boot_val */
6201                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6202
6203                                 /* reset_val */
6204                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6205                         }
6206                         break;
6207
6208                 case PGC_INT:
6209                         {
6210                                 struct config_int *lconf = (struct config_int *) conf;
6211
6212                                 /* min_val */
6213                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6214                                 values[9] = pstrdup(buffer);
6215
6216                                 /* max_val */
6217                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6218                                 values[10] = pstrdup(buffer);
6219
6220                                 /* enumvals */
6221                                 values[11] = NULL;
6222
6223                                 /* boot_val */
6224                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6225                                 values[12] = pstrdup(buffer);
6226
6227                                 /* reset_val */
6228                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6229                                 values[13] = pstrdup(buffer);
6230                         }
6231                         break;
6232
6233                 case PGC_REAL:
6234                         {
6235                                 struct config_real *lconf = (struct config_real *) conf;
6236
6237                                 /* min_val */
6238                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6239                                 values[9] = pstrdup(buffer);
6240
6241                                 /* max_val */
6242                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6243                                 values[10] = pstrdup(buffer);
6244
6245                                 /* enumvals */
6246                                 values[11] = NULL;
6247
6248                                 /* boot_val */
6249                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6250                                 values[12] = pstrdup(buffer);
6251
6252                                 /* reset_val */
6253                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6254                                 values[13] = pstrdup(buffer);
6255                         }
6256                         break;
6257
6258                 case PGC_STRING:
6259                         {
6260                                 struct config_string *lconf = (struct config_string *) conf;
6261
6262                                 /* min_val */
6263                                 values[9] = NULL;
6264
6265                                 /* max_val */
6266                                 values[10] = NULL;
6267
6268                                 /* enumvals */
6269                                 values[11] = NULL;
6270
6271                                 /* boot_val */
6272                                 if (lconf->boot_val == NULL)
6273                                         values[12] = NULL;
6274                                 else
6275                                         values[12] = pstrdup(lconf->boot_val);
6276
6277                                 /* reset_val */
6278                                 if (lconf->reset_val == NULL)
6279                                         values[13] = NULL;
6280                                 else
6281                                         values[13] = pstrdup(lconf->reset_val);
6282                         }
6283                         break;
6284
6285                 case PGC_ENUM:
6286                         {
6287                                 struct config_enum *lconf = (struct config_enum *) conf;
6288
6289                                 /* min_val */
6290                                 values[9] = NULL;
6291
6292                                 /* max_val */
6293                                 values[10] = NULL;
6294
6295                                 /* enumvals */
6296                                 /* NOTE! enumvals with double quotes in them are not supported! */
6297                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6298                                                                                                          "{\"", "\"}", "\",\"");
6299
6300                                 /* boot_val */
6301                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6302                                                                                                                                  lconf->boot_val));
6303
6304                                 /* reset_val */
6305                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6306                                                                                                                                  lconf->reset_val));
6307                         }
6308                         break;
6309
6310                 default:
6311                         {
6312                                 /*
6313                                  * should never get here, but in case we do, set 'em to NULL
6314                                  */
6315
6316                                 /* min_val */
6317                                 values[9] = NULL;
6318
6319                                 /* max_val */
6320                                 values[10] = NULL;
6321
6322                                 /* enumvals */
6323                                 values[11] = NULL;
6324
6325                                 /* boot_val */
6326                                 values[12] = NULL;
6327
6328                                 /* reset_val */
6329                                 values[13] = NULL;
6330                         }
6331                         break;
6332         }
6333
6334         /*
6335          * If the setting came from a config file, set the source location.
6336          * For security reasons, we don't show source file/line number for
6337          * non-superusers.
6338          */
6339         if (conf->source == PGC_S_FILE && superuser())
6340         {
6341                 values[14] = conf->sourcefile;
6342                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6343                 values[15] = pstrdup(buffer);
6344         }
6345         else
6346         {
6347                 values[14] = NULL;
6348                 values[15] = NULL;
6349         }
6350 }
6351
6352 /*
6353  * Return the total number of GUC variables
6354  */
6355 int
6356 GetNumConfigOptions(void)
6357 {
6358         return num_guc_variables;
6359 }
6360
6361 /*
6362  * show_config_by_name - equiv to SHOW X command but implemented as
6363  * a function.
6364  */
6365 Datum
6366 show_config_by_name(PG_FUNCTION_ARGS)
6367 {
6368         char       *varname;
6369         char       *varval;
6370
6371         /* Get the GUC variable name */
6372         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6373
6374         /* Get the value */
6375         varval = GetConfigOptionByName(varname, NULL);
6376
6377         /* Convert to text */
6378         PG_RETURN_TEXT_P(cstring_to_text(varval));
6379 }
6380
6381 /*
6382  * show_all_settings - equiv to SHOW ALL command but implemented as
6383  * a Table Function.
6384  */
6385 #define NUM_PG_SETTINGS_ATTS    16
6386
6387 Datum
6388 show_all_settings(PG_FUNCTION_ARGS)
6389 {
6390         FuncCallContext *funcctx;
6391         TupleDesc       tupdesc;
6392         int                     call_cntr;
6393         int                     max_calls;
6394         AttInMetadata *attinmeta;
6395         MemoryContext oldcontext;
6396
6397         /* stuff done only on the first call of the function */
6398         if (SRF_IS_FIRSTCALL())
6399         {
6400                 /* create a function context for cross-call persistence */
6401                 funcctx = SRF_FIRSTCALL_INIT();
6402
6403                 /*
6404                  * switch to memory context appropriate for multiple function calls
6405                  */
6406                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6407
6408                 /*
6409                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6410                  * of the appropriate types
6411                  */
6412                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6413                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6414                                                    TEXTOID, -1, 0);
6415                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6416                                                    TEXTOID, -1, 0);
6417                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6418                                                    TEXTOID, -1, 0);
6419                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6420                                                    TEXTOID, -1, 0);
6421                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6422                                                    TEXTOID, -1, 0);
6423                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6424                                                    TEXTOID, -1, 0);
6425                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6426                                                    TEXTOID, -1, 0);
6427                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6428                                                    TEXTOID, -1, 0);
6429                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6430                                                    TEXTOID, -1, 0);
6431                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6432                                                    TEXTOID, -1, 0);
6433                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6434                                                    TEXTOID, -1, 0);
6435                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6436                                                    TEXTARRAYOID, -1, 0);
6437                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6438                                                    TEXTOID, -1, 0);
6439                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6440                                                    TEXTOID, -1, 0);
6441                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6442                                                    TEXTOID, -1, 0);
6443                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6444                                                    INT4OID, -1, 0);
6445
6446                 /*
6447                  * Generate attribute metadata needed later to produce tuples from raw
6448                  * C strings
6449                  */
6450                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6451                 funcctx->attinmeta = attinmeta;
6452
6453                 /* total number of tuples to be returned */
6454                 funcctx->max_calls = GetNumConfigOptions();
6455
6456                 MemoryContextSwitchTo(oldcontext);
6457         }
6458
6459         /* stuff done on every call of the function */
6460         funcctx = SRF_PERCALL_SETUP();
6461
6462         call_cntr = funcctx->call_cntr;
6463         max_calls = funcctx->max_calls;
6464         attinmeta = funcctx->attinmeta;
6465
6466         if (call_cntr < max_calls)      /* do when there is more left to send */
6467         {
6468                 char       *values[NUM_PG_SETTINGS_ATTS];
6469                 bool            noshow;
6470                 HeapTuple       tuple;
6471                 Datum           result;
6472
6473                 /*
6474                  * Get the next visible GUC variable name and value
6475                  */
6476                 do
6477                 {
6478                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6479                         if (noshow)
6480                         {
6481                                 /* bump the counter and get the next config setting */
6482                                 call_cntr = ++funcctx->call_cntr;
6483
6484                                 /* make sure we haven't gone too far now */
6485                                 if (call_cntr >= max_calls)
6486                                         SRF_RETURN_DONE(funcctx);
6487                         }
6488                 } while (noshow);
6489
6490                 /* build a tuple */
6491                 tuple = BuildTupleFromCStrings(attinmeta, values);
6492
6493                 /* make the tuple into a datum */
6494                 result = HeapTupleGetDatum(tuple);
6495
6496                 SRF_RETURN_NEXT(funcctx, result);
6497         }
6498         else
6499         {
6500                 /* do when there is no more left */
6501                 SRF_RETURN_DONE(funcctx);
6502         }
6503 }
6504
6505 static char *
6506 _ShowOption(struct config_generic * record, bool use_units)
6507 {
6508         char            buffer[256];
6509         const char *val;
6510
6511         switch (record->vartype)
6512         {
6513                 case PGC_BOOL:
6514                         {
6515                                 struct config_bool *conf = (struct config_bool *) record;
6516
6517                                 if (conf->show_hook)
6518                                         val = (*conf->show_hook) ();
6519                                 else
6520                                         val = *conf->variable ? "on" : "off";
6521                         }
6522                         break;
6523
6524                 case PGC_INT:
6525                         {
6526                                 struct config_int *conf = (struct config_int *) record;
6527
6528                                 if (conf->show_hook)
6529                                         val = (*conf->show_hook) ();
6530                                 else
6531                                 {
6532                                         /*
6533                                          * Use int64 arithmetic to avoid overflows in units
6534                                          * conversion.  If INT64_IS_BUSTED we might overflow
6535                                          * anyway and print bogus answers, but there are few
6536                                          * enough such machines that it doesn't seem worth
6537                                          * trying harder.
6538                                          */
6539                                         int64           result = *conf->variable;
6540                                         const char *unit;
6541
6542                                         if (use_units && result > 0 &&
6543                                                 (record->flags & GUC_UNIT_MEMORY))
6544                                         {
6545                                                 switch (record->flags & GUC_UNIT_MEMORY)
6546                                                 {
6547                                                         case GUC_UNIT_BLOCKS:
6548                                                                 result *= BLCKSZ / 1024;
6549                                                                 break;
6550                                                         case GUC_UNIT_XBLOCKS:
6551                                                                 result *= XLOG_BLCKSZ / 1024;
6552                                                                 break;
6553                                                 }
6554
6555                                                 if (result % KB_PER_GB == 0)
6556                                                 {
6557                                                         result /= KB_PER_GB;
6558                                                         unit = "GB";
6559                                                 }
6560                                                 else if (result % KB_PER_MB == 0)
6561                                                 {
6562                                                         result /= KB_PER_MB;
6563                                                         unit = "MB";
6564                                                 }
6565                                                 else
6566                                                 {
6567                                                         unit = "kB";
6568                                                 }
6569                                         }
6570                                         else if (use_units && result > 0 &&
6571                                                          (record->flags & GUC_UNIT_TIME))
6572                                         {
6573                                                 switch (record->flags & GUC_UNIT_TIME)
6574                                                 {
6575                                                         case GUC_UNIT_S:
6576                                                                 result *= MS_PER_S;
6577                                                                 break;
6578                                                         case GUC_UNIT_MIN:
6579                                                                 result *= MS_PER_MIN;
6580                                                                 break;
6581                                                 }
6582
6583                                                 if (result % MS_PER_D == 0)
6584                                                 {
6585                                                         result /= MS_PER_D;
6586                                                         unit = "d";
6587                                                 }
6588                                                 else if (result % MS_PER_H == 0)
6589                                                 {
6590                                                         result /= MS_PER_H;
6591                                                         unit = "h";
6592                                                 }
6593                                                 else if (result % MS_PER_MIN == 0)
6594                                                 {
6595                                                         result /= MS_PER_MIN;
6596                                                         unit = "min";
6597                                                 }
6598                                                 else if (result % MS_PER_S == 0)
6599                                                 {
6600                                                         result /= MS_PER_S;
6601                                                         unit = "s";
6602                                                 }
6603                                                 else
6604                                                 {
6605                                                         unit = "ms";
6606                                                 }
6607                                         }
6608                                         else
6609                                                 unit = "";
6610
6611                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6612                                                          result, unit);
6613                                         val = buffer;
6614                                 }
6615                         }
6616                         break;
6617
6618                 case PGC_REAL:
6619                         {
6620                                 struct config_real *conf = (struct config_real *) record;
6621
6622                                 if (conf->show_hook)
6623                                         val = (*conf->show_hook) ();
6624                                 else
6625                                 {
6626                                         snprintf(buffer, sizeof(buffer), "%g",
6627                                                          *conf->variable);
6628                                         val = buffer;
6629                                 }
6630                         }
6631                         break;
6632
6633                 case PGC_STRING:
6634                         {
6635                                 struct config_string *conf = (struct config_string *) record;
6636
6637                                 if (conf->show_hook)
6638                                         val = (*conf->show_hook) ();
6639                                 else if (*conf->variable && **conf->variable)
6640                                         val = *conf->variable;
6641                                 else
6642                                         val = "";
6643                         }
6644                         break;
6645
6646                 case PGC_ENUM:
6647                         {
6648                                 struct config_enum *conf = (struct config_enum *) record;
6649
6650                                 if(conf->show_hook)
6651                                         val = (*conf->show_hook) ();
6652                                 else
6653                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6654                         }
6655                         break;
6656
6657                 default:
6658                         /* just to keep compiler quiet */
6659                         val = "???";
6660                         break;
6661         }
6662
6663         return pstrdup(val);
6664 }
6665
6666
6667 /*
6668  * Attempt (badly) to detect if a proposed new GUC setting is the same
6669  * as the current value.
6670  *
6671  * XXX this does not really work because it doesn't account for the
6672  * effects of canonicalization of string values by assign_hooks.
6673  */
6674 static bool
6675 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6676 {
6677         /* newvalue == NULL isn't supported */
6678         Assert(newvalue != NULL);
6679
6680         switch (record->vartype)
6681         {
6682                 case PGC_BOOL:
6683                         {
6684                                 struct config_bool *conf = (struct config_bool *) record;
6685                                 bool            newval;
6686
6687                                 return parse_bool(newvalue, &newval)
6688                                         && *conf->variable == newval;
6689                         }
6690                 case PGC_INT:
6691                         {
6692                                 struct config_int *conf = (struct config_int *) record;
6693                                 int                     newval;
6694
6695                                 return parse_int(newvalue, &newval, record->flags, NULL)
6696                                         && *conf->variable == newval;
6697                         }
6698                 case PGC_REAL:
6699                         {
6700                                 struct config_real *conf = (struct config_real *) record;
6701                                 double          newval;
6702
6703                                 return parse_real(newvalue, &newval)
6704                                         && *conf->variable == newval;
6705                         }
6706                 case PGC_STRING:
6707                         {
6708                                 struct config_string *conf = (struct config_string *) record;
6709
6710                                 return *conf->variable != NULL &&
6711                                         strcmp(*conf->variable, newvalue) == 0;
6712                         }
6713
6714                 case PGC_ENUM:
6715                         {
6716                                 struct config_enum *conf = (struct config_enum *) record;
6717                                 int                     newval;
6718
6719                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6720                                         *conf->variable == newval;
6721                         }
6722         }
6723
6724         return false;
6725 }
6726
6727
6728 #ifdef EXEC_BACKEND
6729
6730 /*
6731  *      These routines dump out all non-default GUC options into a binary
6732  *      file that is read by all exec'ed backends.  The format is:
6733  *
6734  *              variable name, string, null terminated
6735  *              variable value, string, null terminated
6736  *              variable source, integer
6737  */
6738 static void
6739 write_one_nondefault_variable(FILE *fp, struct config_generic *gconf)
6740 {
6741         if (gconf->source == PGC_S_DEFAULT)
6742                 return;
6743
6744         fprintf(fp, "%s", gconf->name);
6745         fputc(0, fp);
6746
6747         switch (gconf->vartype)
6748         {
6749                 case PGC_BOOL:
6750                 {
6751                         struct config_bool *conf = (struct config_bool *) gconf;
6752
6753                         if (*conf->variable)
6754                                 fprintf(fp, "true");
6755                         else
6756                                 fprintf(fp, "false");
6757                 }
6758                 break;
6759
6760                 case PGC_INT:
6761                 {
6762                         struct config_int *conf = (struct config_int *) gconf;
6763
6764                         fprintf(fp, "%d", *conf->variable);
6765                 }
6766                 break;
6767
6768                 case PGC_REAL:
6769                 {
6770                         struct config_real *conf = (struct config_real *) gconf;
6771
6772                         /* Could lose precision here? */
6773                         fprintf(fp, "%f", *conf->variable);
6774                 }
6775                 break;
6776
6777                 case PGC_STRING:
6778                 {
6779                         struct config_string *conf = (struct config_string *) gconf;
6780
6781                         fprintf(fp, "%s", *conf->variable);
6782                 }
6783                 break;
6784
6785                 case PGC_ENUM:
6786                 {
6787                         struct config_enum *conf = (struct config_enum *) gconf;
6788
6789                         fprintf(fp, "%s",
6790                                         config_enum_lookup_by_value(conf, *conf->variable));
6791                 }
6792                 break;
6793         }
6794
6795         fputc(0, fp);
6796
6797         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6798 }
6799
6800 void
6801 write_nondefault_variables(GucContext context)
6802 {
6803         int                     elevel;
6804         FILE       *fp;
6805         struct config_generic *cvc_conf;
6806         int                     i;
6807
6808         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6809
6810         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6811
6812         /*
6813          * Open file
6814          */
6815         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6816         if (!fp)
6817         {
6818                 ereport(elevel,
6819                                 (errcode_for_file_access(),
6820                                  errmsg("could not write to file \"%s\": %m",
6821                                                 CONFIG_EXEC_PARAMS_NEW)));
6822                 return;
6823         }
6824
6825         /*
6826          * custom_variable_classes must be written out first; otherwise we might
6827          * reject custom variable values while reading the file.
6828          */
6829         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6830         if (cvc_conf)
6831                 write_one_nondefault_variable(fp, cvc_conf);
6832
6833         for (i = 0; i < num_guc_variables; i++)
6834         {
6835                 struct config_generic *gconf = guc_variables[i];
6836
6837                 if (gconf != cvc_conf)
6838                         write_one_nondefault_variable(fp, gconf);
6839         }
6840
6841         if (FreeFile(fp))
6842         {
6843                 ereport(elevel,
6844                                 (errcode_for_file_access(),
6845                                  errmsg("could not write to file \"%s\": %m",
6846                                                 CONFIG_EXEC_PARAMS_NEW)));
6847                 return;
6848         }
6849
6850         /*
6851          * Put new file in place.  This could delay on Win32, but we don't hold
6852          * any exclusive locks.
6853          */
6854         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6855 }
6856
6857
6858 /*
6859  *      Read string, including null byte from file
6860  *
6861  *      Return NULL on EOF and nothing read
6862  */
6863 static char *
6864 read_string_with_null(FILE *fp)
6865 {
6866         int                     i = 0,
6867                                 ch,
6868                                 maxlen = 256;
6869         char       *str = NULL;
6870
6871         do
6872         {
6873                 if ((ch = fgetc(fp)) == EOF)
6874                 {
6875                         if (i == 0)
6876                                 return NULL;
6877                         else
6878                                 elog(FATAL, "invalid format of exec config params file");
6879                 }
6880                 if (i == 0)
6881                         str = guc_malloc(FATAL, maxlen);
6882                 else if (i == maxlen)
6883                         str = guc_realloc(FATAL, str, maxlen *= 2);
6884                 str[i++] = ch;
6885         } while (ch != 0);
6886
6887         return str;
6888 }
6889
6890
6891 /*
6892  *      This routine loads a previous postmaster dump of its non-default
6893  *      settings.
6894  */
6895 void
6896 read_nondefault_variables(void)
6897 {
6898         FILE       *fp;
6899         char       *varname,
6900                            *varvalue;
6901         int                     varsource;
6902
6903         /*
6904          * Open file
6905          */
6906         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6907         if (!fp)
6908         {
6909                 /* File not found is fine */
6910                 if (errno != ENOENT)
6911                         ereport(FATAL,
6912                                         (errcode_for_file_access(),
6913                                          errmsg("could not read from file \"%s\": %m",
6914                                                         CONFIG_EXEC_PARAMS)));
6915                 return;
6916         }
6917
6918         for (;;)
6919         {
6920                 struct config_generic *record;
6921
6922                 if ((varname = read_string_with_null(fp)) == NULL)
6923                         break;
6924
6925                 if ((record = find_option(varname, true, FATAL)) == NULL)
6926                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6927                 if ((varvalue = read_string_with_null(fp)) == NULL)
6928                         elog(FATAL, "invalid format of exec config params file");
6929                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6930                         elog(FATAL, "invalid format of exec config params file");
6931
6932                 (void) set_config_option(varname, varvalue, record->context,
6933                                                                  varsource, GUC_ACTION_SET, true);
6934                 free(varname);
6935                 free(varvalue);
6936         }
6937
6938         FreeFile(fp);
6939 }
6940 #endif   /* EXEC_BACKEND */
6941
6942
6943 /*
6944  * A little "long argument" simulation, although not quite GNU
6945  * compliant. Takes a string of the form "some-option=some value" and
6946  * returns name = "some_option" and value = "some value" in malloc'ed
6947  * storage. Note that '-' is converted to '_' in the option name. If
6948  * there is no '=' in the input string then value will be NULL.
6949  */
6950 void
6951 ParseLongOption(const char *string, char **name, char **value)
6952 {
6953         size_t          equal_pos;
6954         char       *cp;
6955
6956         AssertArg(string);
6957         AssertArg(name);
6958         AssertArg(value);
6959
6960         equal_pos = strcspn(string, "=");
6961
6962         if (string[equal_pos] == '=')
6963         {
6964                 *name = guc_malloc(FATAL, equal_pos + 1);
6965                 strlcpy(*name, string, equal_pos + 1);
6966
6967                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6968         }
6969         else
6970         {
6971                 /* no equal sign in string */
6972                 *name = guc_strdup(FATAL, string);
6973                 *value = NULL;
6974         }
6975
6976         for (cp = *name; *cp; cp++)
6977                 if (*cp == '-')
6978                         *cp = '_';
6979 }
6980
6981
6982 /*
6983  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6984  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6985  *
6986  * The array parameter must be an array of TEXT (it must not be NULL).
6987  */
6988 void
6989 ProcessGUCArray(ArrayType *array,
6990                                 GucContext context, GucSource source, GucAction action)
6991 {
6992         int                     i;
6993
6994         Assert(array != NULL);
6995         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6996         Assert(ARR_NDIM(array) == 1);
6997         Assert(ARR_LBOUND(array)[0] == 1);
6998
6999         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7000         {
7001                 Datum           d;
7002                 bool            isnull;
7003                 char       *s;
7004                 char       *name;
7005                 char       *value;
7006
7007                 d = array_ref(array, 1, &i,
7008                                           -1 /* varlenarray */ ,
7009                                           -1 /* TEXT's typlen */ ,
7010                                           false /* TEXT's typbyval */ ,
7011                                           'i' /* TEXT's typalign */ ,
7012                                           &isnull);
7013
7014                 if (isnull)
7015                         continue;
7016
7017                 s = TextDatumGetCString(d);
7018
7019                 ParseLongOption(s, &name, &value);
7020                 if (!value)
7021                 {
7022                         ereport(WARNING,
7023                                         (errcode(ERRCODE_SYNTAX_ERROR),
7024                                          errmsg("could not parse setting for parameter \"%s\"",
7025                                                         name)));
7026                         free(name);
7027                         continue;
7028                 }
7029
7030                 (void) set_config_option(name, value, context, source, action, true);
7031
7032                 free(name);
7033                 if (value)
7034                         free(value);
7035         }
7036 }
7037
7038
7039 /*
7040  * Add an entry to an option array.  The array parameter may be NULL
7041  * to indicate the current table entry is NULL.
7042  */
7043 ArrayType *
7044 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
7045 {
7046         const char *varname;
7047         Datum           datum;
7048         char       *newval;
7049         ArrayType  *a;
7050
7051         Assert(name);
7052         Assert(value);
7053
7054         /* test if the option is valid */
7055         set_config_option(name, value,
7056                                           superuser() ? PGC_SUSET : PGC_USERSET,
7057                                           PGC_S_TEST, GUC_ACTION_SET, false);
7058
7059         /* convert name to canonical spelling, so we can use plain strcmp */
7060         (void) GetConfigOptionByName(name, &varname);
7061         name = varname;
7062
7063         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7064         sprintf(newval, "%s=%s", name, value);
7065         datum = CStringGetTextDatum(newval);
7066
7067         if (array)
7068         {
7069                 int                     index;
7070                 bool            isnull;
7071                 int                     i;
7072
7073                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7074                 Assert(ARR_NDIM(array) == 1);
7075                 Assert(ARR_LBOUND(array)[0] == 1);
7076
7077                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7078
7079                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7080                 {
7081                         Datum           d;
7082                         char       *current;
7083
7084                         d = array_ref(array, 1, &i,
7085                                                   -1 /* varlenarray */ ,
7086                                                   -1 /* TEXT's typlen */ ,
7087                                                   false /* TEXT's typbyval */ ,
7088                                                   'i' /* TEXT's typalign */ ,
7089                                                   &isnull);
7090                         if (isnull)
7091                                 continue;
7092                         current = TextDatumGetCString(d);
7093                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7094                         {
7095                                 index = i;
7096                                 break;
7097                         }
7098                 }
7099
7100                 a = array_set(array, 1, &index,
7101                                           datum,
7102                                           false,
7103                                           -1 /* varlena array */ ,
7104                                           -1 /* TEXT's typlen */ ,
7105                                           false /* TEXT's typbyval */ ,
7106                                           'i' /* TEXT's typalign */ );
7107         }
7108         else
7109                 a = construct_array(&datum, 1,
7110                                                         TEXTOID,
7111                                                         -1, false, 'i');
7112
7113         return a;
7114 }
7115
7116
7117 /*
7118  * Delete an entry from an option array.  The array parameter may be NULL
7119  * to indicate the current table entry is NULL.  Also, if the return value
7120  * is NULL then a null should be stored.
7121  */
7122 ArrayType *
7123 GUCArrayDelete(ArrayType *array, const char *name)
7124 {
7125         const char *varname;
7126         ArrayType  *newarray;
7127         int                     i;
7128         int                     index;
7129
7130         Assert(name);
7131
7132         /* test if the option is valid */
7133         set_config_option(name, NULL,
7134                                           superuser() ? PGC_SUSET : PGC_USERSET,
7135                                           PGC_S_TEST, GUC_ACTION_SET, false);
7136
7137         /* convert name to canonical spelling, so we can use plain strcmp */
7138         (void) GetConfigOptionByName(name, &varname);
7139         name = varname;
7140
7141         /* if array is currently null, then surely nothing to delete */
7142         if (!array)
7143                 return NULL;
7144
7145         newarray = NULL;
7146         index = 1;
7147
7148         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7149         {
7150                 Datum           d;
7151                 char       *val;
7152                 bool            isnull;
7153
7154                 d = array_ref(array, 1, &i,
7155                                           -1 /* varlenarray */ ,
7156                                           -1 /* TEXT's typlen */ ,
7157                                           false /* TEXT's typbyval */ ,
7158                                           'i' /* TEXT's typalign */ ,
7159                                           &isnull);
7160                 if (isnull)
7161                         continue;
7162                 val = TextDatumGetCString(d);
7163
7164                 /* ignore entry if it's what we want to delete */
7165                 if (strncmp(val, name, strlen(name)) == 0
7166                         && val[strlen(name)] == '=')
7167                         continue;
7168
7169                 /* else add it to the output array */
7170                 if (newarray)
7171                 {
7172                         newarray = array_set(newarray, 1, &index,
7173                                                                  d,
7174                                                                  false,
7175                                                                  -1 /* varlenarray */ ,
7176                                                                  -1 /* TEXT's typlen */ ,
7177                                                                  false /* TEXT's typbyval */ ,
7178                                                                  'i' /* TEXT's typalign */ );
7179                 }
7180                 else
7181                         newarray = construct_array(&d, 1,
7182                                                                            TEXTOID,
7183                                                                            -1, false, 'i');
7184
7185                 index++;
7186         }
7187
7188         return newarray;
7189 }
7190
7191
7192 /*
7193  * assign_hook and show_hook subroutines
7194  */
7195
7196 static const char *
7197 assign_log_destination(const char *value, bool doit, GucSource source)
7198 {
7199         char       *rawstring;
7200         List       *elemlist;
7201         ListCell   *l;
7202         int                     newlogdest = 0;
7203
7204         /* Need a modifiable copy of string */
7205         rawstring = pstrdup(value);
7206
7207         /* Parse string into list of identifiers */
7208         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7209         {
7210                 /* syntax error in list */
7211                 pfree(rawstring);
7212                 list_free(elemlist);
7213                 ereport(GUC_complaint_elevel(source),
7214                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7215                         errmsg("invalid list syntax for parameter \"log_destination\"")));
7216                 return NULL;
7217         }
7218
7219         foreach(l, elemlist)
7220         {
7221                 char       *tok = (char *) lfirst(l);
7222
7223                 if (pg_strcasecmp(tok, "stderr") == 0)
7224                         newlogdest |= LOG_DESTINATION_STDERR;
7225                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7226                         newlogdest |= LOG_DESTINATION_CSVLOG;
7227 #ifdef HAVE_SYSLOG
7228                 else if (pg_strcasecmp(tok, "syslog") == 0)
7229                         newlogdest |= LOG_DESTINATION_SYSLOG;
7230 #endif
7231 #ifdef WIN32
7232                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7233                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7234 #endif
7235                 else
7236                 {
7237                         ereport(GUC_complaint_elevel(source),
7238                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7239                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7240                                                  tok)));
7241                         pfree(rawstring);
7242                         list_free(elemlist);
7243                         return NULL;
7244                 }
7245         }
7246
7247         if (doit)
7248                 Log_destination = newlogdest;
7249
7250         pfree(rawstring);
7251         list_free(elemlist);
7252
7253         return value;
7254 }
7255
7256 #ifdef HAVE_SYSLOG
7257
7258 static bool
7259 assign_syslog_facility(int newval, bool doit, GucSource source)
7260 {
7261         if (doit)
7262                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7263                                                           newval);
7264
7265         return true;
7266 }
7267
7268 static const char *
7269 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7270 {
7271         if (doit)
7272                 set_syslog_parameters(ident, syslog_facility);
7273
7274         return ident;
7275 }
7276 #endif   /* HAVE_SYSLOG */
7277
7278
7279 static bool
7280 assign_session_replication_role(int newval, bool doit, GucSource source)
7281 {
7282         /*
7283          * Must flush the plan cache when changing replication role; but don't
7284          * flush unnecessarily.
7285          */
7286         if (doit && SessionReplicationRole != newval)
7287         {
7288                 ResetPlanCache();
7289         }
7290
7291         return true;
7292 }
7293
7294 static const char *
7295 show_num_temp_buffers(void)
7296 {
7297         /*
7298          * We show the GUC var until local buffers have been initialized, and
7299          * NLocBuffer afterwards.
7300          */
7301         static char nbuf[32];
7302
7303         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7304         return nbuf;
7305 }
7306
7307 static bool
7308 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7309 {
7310         if (!newval)
7311         {
7312                 ereport(GUC_complaint_elevel(source),
7313                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7314                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7315                 return false;
7316         }
7317         return true;
7318 }
7319
7320 static const char *
7321 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7322 {
7323         /*
7324          * Check syntax. newval must be a comma separated list of identifiers.
7325          * Whitespace is allowed but removed from the result.
7326          */
7327         bool            hasSpaceAfterToken = false;
7328         const char *cp = newval;
7329         int                     symLen = 0;
7330         char            c;
7331         StringInfoData buf;
7332
7333         initStringInfo(&buf);
7334         while ((c = *cp++) != '\0')
7335         {
7336                 if (isspace((unsigned char) c))
7337                 {
7338                         if (symLen > 0)
7339                                 hasSpaceAfterToken = true;
7340                         continue;
7341                 }
7342
7343                 if (c == ',')
7344                 {
7345                         if (symLen > 0)         /* terminate identifier */
7346                         {
7347                                 appendStringInfoChar(&buf, ',');
7348                                 symLen = 0;
7349                         }
7350                         hasSpaceAfterToken = false;
7351                         continue;
7352                 }
7353
7354                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7355                 {
7356                         /*
7357                          * Syntax error due to token following space after token or
7358                          * non-identifier character
7359                          */
7360                         pfree(buf.data);
7361                         return NULL;
7362                 }
7363                 appendStringInfoChar(&buf, c);
7364                 symLen++;
7365         }
7366
7367         /* Remove stray ',' at end */
7368         if (symLen == 0 && buf.len > 0)
7369                 buf.data[--buf.len] = '\0';
7370
7371         /* GUC wants the result malloc'd */
7372         newval = guc_strdup(LOG, buf.data);
7373
7374         pfree(buf.data);
7375         return newval;
7376 }
7377
7378 static bool
7379 assign_debug_assertions(bool newval, bool doit, GucSource source)
7380 {
7381 #ifndef USE_ASSERT_CHECKING
7382         if (newval)
7383         {
7384                 ereport(GUC_complaint_elevel(source),
7385                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7386                            errmsg("assertion checking is not supported by this build")));
7387                 return false;
7388         }
7389 #endif
7390         return true;
7391 }
7392
7393 static bool
7394 assign_ssl(bool newval, bool doit, GucSource source)
7395 {
7396 #ifndef USE_SSL
7397         if (newval)
7398         {
7399                 ereport(GUC_complaint_elevel(source),
7400                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7401                                  errmsg("SSL is not supported by this build")));
7402                 return false;
7403         }
7404 #endif
7405         return true;
7406 }
7407
7408 static bool
7409 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7410 {
7411         if (newval && log_statement_stats)
7412         {
7413                 ereport(GUC_complaint_elevel(source),
7414                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7415                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7416                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7417                 if (source != PGC_S_OVERRIDE)
7418                         return false;
7419         }
7420         return true;
7421 }
7422
7423 static bool
7424 assign_log_stats(bool newval, bool doit, GucSource source)
7425 {
7426         if (newval &&
7427                 (log_parser_stats || log_planner_stats || log_executor_stats))
7428         {
7429                 ereport(GUC_complaint_elevel(source),
7430                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7431                                  errmsg("cannot enable \"log_statement_stats\" when "
7432                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7433                                                 "or \"log_executor_stats\" is true")));
7434                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7435                 if (source != PGC_S_OVERRIDE)
7436                         return false;
7437         }
7438         return true;
7439 }
7440
7441 static bool
7442 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7443 {
7444         /* Can't go to r/w mode inside a r/o transaction */
7445         if (newval == false && XactReadOnly && IsSubTransaction())
7446         {
7447                 ereport(GUC_complaint_elevel(source),
7448                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7449                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7450                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7451                 if (source != PGC_S_OVERRIDE)
7452                         return false;
7453         }
7454         return true;
7455 }
7456
7457 static const char *
7458 assign_canonical_path(const char *newval, bool doit, GucSource source)
7459 {
7460         if (doit)
7461         {
7462                 char       *canon_val = guc_strdup(ERROR, newval);
7463
7464                 canonicalize_path(canon_val);
7465                 return canon_val;
7466         }
7467         else
7468                 return newval;
7469 }
7470
7471 static const char *
7472 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7473 {
7474         /*
7475          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7476          * When we see this we just do nothing.  If this value isn't overridden
7477          * from the config file then pg_timezone_abbrev_initialize() will
7478          * eventually replace it with "Default".  This hack has two purposes: to
7479          * avoid wasting cycles loading values that might soon be overridden from
7480          * the config file, and to avoid trying to read the timezone abbrev files
7481          * during InitializeGUCOptions().  The latter doesn't work in an
7482          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7483          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7484          * delay initializing TimeZone ... if we have any more, we should try to
7485          * clean up and centralize this mechanism ...)
7486          */
7487         if (strcmp(newval, "UNKNOWN") == 0)
7488         {
7489                 return newval;
7490         }
7491
7492         /* Loading abbrev file is expensive, so only do it when value changes */
7493         if (timezone_abbreviations_string == NULL ||
7494                 strcmp(timezone_abbreviations_string, newval) != 0)
7495         {
7496                 int                     elevel;
7497
7498                 /*
7499                  * If reading config file, only the postmaster should bleat loudly
7500                  * about problems.      Otherwise, it's just this one process doing it,
7501                  * and we use WARNING message level.
7502                  */
7503                 if (source == PGC_S_FILE)
7504                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7505                 else
7506                         elevel = WARNING;
7507                 if (!load_tzoffsets(newval, doit, elevel))
7508                         return NULL;
7509         }
7510         return newval;
7511 }
7512
7513 /*
7514  * pg_timezone_abbrev_initialize --- set default value if not done already
7515  *
7516  * This is called after initial loading of postgresql.conf.  If no
7517  * timezone_abbreviations setting was found therein, select default.
7518  */
7519 void
7520 pg_timezone_abbrev_initialize(void)
7521 {
7522         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7523         {
7524                 SetConfigOption("timezone_abbreviations", "Default",
7525                                                 PGC_POSTMASTER, PGC_S_ARGV);
7526         }
7527 }
7528
7529 static const char *
7530 show_archive_command(void)
7531 {
7532         if (XLogArchiveMode)
7533                 return XLogArchiveCommand;
7534         else
7535                 return "(disabled)";
7536 }
7537
7538 static bool
7539 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7540 {
7541         if (doit)
7542                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7543
7544         return true;
7545 }
7546
7547 static const char *
7548 show_tcp_keepalives_idle(void)
7549 {
7550         static char nbuf[16];
7551
7552         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7553         return nbuf;
7554 }
7555
7556 static bool
7557 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7558 {
7559         if (doit)
7560                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7561
7562         return true;
7563 }
7564
7565 static const char *
7566 show_tcp_keepalives_interval(void)
7567 {
7568         static char nbuf[16];
7569
7570         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7571         return nbuf;
7572 }
7573
7574 static bool
7575 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7576 {
7577         if (doit)
7578                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7579
7580         return true;
7581 }
7582
7583 static const char *
7584 show_tcp_keepalives_count(void)
7585 {
7586         static char nbuf[16];
7587
7588         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7589         return nbuf;
7590 }
7591
7592 static bool
7593 assign_maxconnections(int newval, bool doit, GucSource source)
7594 {
7595         if (newval + autovacuum_max_workers > INT_MAX / 4)
7596                 return false;
7597
7598         if (doit)
7599                 MaxBackends = newval + autovacuum_max_workers;
7600
7601         return true;
7602 }
7603
7604 static bool
7605 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7606 {
7607         if (newval + MaxConnections > INT_MAX / 4)
7608                 return false;
7609
7610         if (doit)
7611                 MaxBackends = newval + MaxConnections;
7612
7613         return true;
7614 }
7615
7616 static bool
7617 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7618 {
7619 #ifdef USE_PREFETCH
7620         double          new_prefetch_pages = 0.0;
7621         int                     i;
7622
7623         /*----------
7624          * The user-visible GUC parameter is the number of drives (spindles),
7625          * which we need to translate to a number-of-pages-to-prefetch target.
7626          *
7627          * The expected number of prefetch pages needed to keep N drives busy is:
7628          *
7629          * drives |   I/O requests
7630          * -------+----------------
7631          *      1 |   1
7632          *      2 |   2/1 + 2/2 = 3
7633          *      3 |   3/1 + 3/2 + 3/3 = 5 1/2
7634          *      4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7635          *      n |   n * H(n)
7636          *
7637          * This is called the "coupon collector problem" and H(n) is called the
7638          * harmonic series.  This could be approximated by n * ln(n), but for
7639          * reasonable numbers of drives we might as well just compute the series.
7640          *
7641          * Alternatively we could set the target to the number of pages necessary
7642          * so that the expected number of active spindles is some arbitrary
7643          * percentage of the total.  This sounds the same but is actually slightly
7644          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7645          * that desired fraction.
7646          *
7647          * Experimental results show that both of these formulas aren't aggressive
7648          * enough, but we don't really have any better proposals.
7649          *
7650          * Note that if newval = 0 (disabled), we must set target = 0.
7651          *----------
7652          */
7653
7654         for (i = 1; i <= newval; i++)
7655                 new_prefetch_pages += (double) newval / (double) i;
7656
7657         /* This range check shouldn't fail, but let's be paranoid */
7658         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7659         {
7660                 if (doit)
7661                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7662                 return true;
7663         }
7664         else
7665                 return false;
7666 #else
7667         return true;
7668 #endif /* USE_PREFETCH */
7669 }
7670
7671 static const char *
7672 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7673 {
7674         if (doit)
7675         {
7676                 if (pgstat_stat_tmpname)
7677                         free(pgstat_stat_tmpname);
7678                 if (pgstat_stat_filename)
7679                         free(pgstat_stat_filename);
7680
7681                 pgstat_stat_tmpname = guc_malloc(FATAL, strlen(newval) + 12);  /* /pgstat.tmp */
7682                 pgstat_stat_filename = guc_malloc(FATAL, strlen(newval) + 13); /* /pgstat.stat */
7683
7684                 sprintf(pgstat_stat_tmpname, "%s/pgstat.tmp", newval);
7685                 sprintf(pgstat_stat_filename, "%s/pgstat.stat", newval);
7686         }
7687
7688         return newval;
7689 }
7690
7691 #include "guc-file.c"