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 1.498 2009/04/02 03:51:43 tgl Exp $
  14  *
  15  *--------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include <ctype.h>
  20 #include <float.h>
  21 #include <math.h>
  22 #include <limits.h>
  23 #include <unistd.h>
  24 #include <sys/stat.h>
  25 #ifdef HAVE_SYSLOG
  26 #include <syslog.h>
  27 #endif
  28
  29 #include "access/gin.h"
  30 #include "access/transam.h"
  31 #include "access/twophase.h"
  32 #include "access/xact.h"
  33 #include "catalog/namespace.h"
  34 #include "commands/async.h"
  35 #include "commands/prepare.h"
  36 #include "commands/vacuum.h"
  37 #include "commands/variable.h"
  38 #include "commands/trigger.h"
  39 #include "funcapi.h"
  40 #include "libpq/auth.h"
  41 #include "libpq/pqformat.h"
  42 #include "miscadmin.h"
  43 #include "optimizer/cost.h"
  44 #include "optimizer/geqo.h"
  45 #include "optimizer/paths.h"
  46 #include "optimizer/planmain.h"
  47 #include "parser/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, 100, 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, 100, 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 to %d",
3582                                                                  conf->gen.name, (int) conf->reset_val);
3583                                         *conf->variable = conf->reset_val;
3584                                         break;
3585                                 }
3586                         case PGC_INT:
3587                                 {
3588                                         struct config_int *conf = (struct config_int *) gconf;
3589
3590                                         if (conf->assign_hook)
3591                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3592                                                                                                    PGC_S_SESSION))
3593                                                         elog(ERROR, "failed to reset %s to %d",
3594                                                                  conf->gen.name, conf->reset_val);
3595                                         *conf->variable = conf->reset_val;
3596                                         break;
3597                                 }
3598                         case PGC_REAL:
3599                                 {
3600                                         struct config_real *conf = (struct config_real *) gconf;
3601
3602                                         if (conf->assign_hook)
3603                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3604                                                                                                    PGC_S_SESSION))
3605                                                         elog(ERROR, "failed to reset %s to %g",
3606                                                                  conf->gen.name, conf->reset_val);
3607                                         *conf->variable = conf->reset_val;
3608                                         break;
3609                                 }
3610                         case PGC_STRING:
3611                                 {
3612                                         struct config_string *conf = (struct config_string *) gconf;
3613                                         char       *str;
3614
3615                                         /* We need not strdup here */
3616                                         str = conf->reset_val;
3617
3618                                         if (conf->assign_hook && str)
3619                                         {
3620                                                 const char *newstr;
3621
3622                                                 newstr = (*conf->assign_hook) (str, true,
3623                                                                                                            PGC_S_SESSION);
3624                                                 if (newstr == NULL)
3625                                                         elog(ERROR, "failed to reset %s to \"%s\"",
3626                                                                  conf->gen.name, str);
3627                                                 else if (newstr != str)
3628                                                 {
3629                                                         /*
3630                                                          * See notes in set_config_option about casting
3631                                                          */
3632                                                         str = (char *) newstr;
3633                                                 }
3634                                         }
3635
3636                                         set_string_field(conf, conf->variable, str);
3637                                         break;
3638                                 }
3639                         case PGC_ENUM:
3640                                 {
3641                                         struct config_enum *conf = (struct config_enum *) gconf;
3642
3643                                         if (conf->assign_hook)
3644                                                 if (!(*conf->assign_hook) (conf->reset_val, true,
3645                                                                                                    PGC_S_SESSION))
3646                                                         elog(ERROR, "failed to reset %s to %s",
3647                                                                  conf->gen.name,
3648                                                                  config_enum_lookup_by_value(conf, conf->reset_val));
3649                                         *conf->variable = conf->reset_val;
3650                                         break;
3651                                 }
3652                 }
3653
3654                 gconf->source = gconf->reset_source;
3655
3656                 if (gconf->flags & GUC_REPORT)
3657                         ReportGUCOption(gconf);
3658         }
3659 }
3660
3661
3662 /*
3663  * push_old_value
3664  *              Push previous state during transactional assignment to a GUC variable.
3665  */
3666 static void
3667 push_old_value(struct config_generic * gconf, GucAction action)
3668 {
3669         GucStack   *stack;
3670
3671         /* If we're not inside a nest level, do nothing */
3672         if (GUCNestLevel == 0)
3673                 return;
3674
3675         /* Do we already have a stack entry of the current nest level? */
3676         stack = gconf->stack;
3677         if (stack && stack->nest_level >= GUCNestLevel)
3678         {
3679                 /* Yes, so adjust its state if necessary */
3680                 Assert(stack->nest_level == GUCNestLevel);
3681                 switch (action)
3682                 {
3683                         case GUC_ACTION_SET:
3684                                 /* SET overrides any prior action at same nest level */
3685                                 if (stack->state == GUC_SET_LOCAL)
3686                                 {
3687                                         /* must discard old masked value */
3688                                         discard_stack_value(gconf, &stack->masked);
3689                                 }
3690                                 stack->state = GUC_SET;
3691                                 break;
3692                         case GUC_ACTION_LOCAL:
3693                                 if (stack->state == GUC_SET)
3694                                 {
3695                                         /* SET followed by SET LOCAL, remember SET's value */
3696                                         set_stack_value(gconf, &stack->masked);
3697                                         stack->state = GUC_SET_LOCAL;
3698                                 }
3699                                 /* in all other cases, no change to stack entry */
3700                                 break;
3701                         case GUC_ACTION_SAVE:
3702                                 /* Could only have a prior SAVE of same variable */
3703                                 Assert(stack->state == GUC_SAVE);
3704                                 break;
3705                 }
3706                 Assert(guc_dirty);              /* must be set already */
3707                 return;
3708         }
3709
3710         /*
3711          * Push a new stack entry
3712          *
3713          * We keep all the stack entries in TopTransactionContext for simplicity.
3714          */
3715         stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
3716                                                                                                 sizeof(GucStack));
3717
3718         stack->prev = gconf->stack;
3719         stack->nest_level = GUCNestLevel;
3720         switch (action)
3721         {
3722                 case GUC_ACTION_SET:
3723                         stack->state = GUC_SET;
3724                         break;
3725                 case GUC_ACTION_LOCAL:
3726                         stack->state = GUC_LOCAL;
3727                         break;
3728                 case GUC_ACTION_SAVE:
3729                         stack->state = GUC_SAVE;
3730                         break;
3731         }
3732         stack->source = gconf->source;
3733         set_stack_value(gconf, &stack->prior);
3734
3735         gconf->stack = stack;
3736
3737         /* Ensure we remember to pop at end of xact */
3738         guc_dirty = true;
3739 }
3740
3741
3742 /*
3743  * Do GUC processing at main transaction start.
3744  */
3745 void
3746 AtStart_GUC(void)
3747 {
3748         /*
3749          * The nest level should be 0 between transactions; if it isn't, somebody
3750          * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
3751          * throw a warning but make no other effort to clean up.
3752          */
3753         if (GUCNestLevel != 0)
3754                 elog(WARNING, "GUC nest level = %d at transaction start",
3755                          GUCNestLevel);
3756         GUCNestLevel = 1;
3757 }
3758
3759 /*
3760  * Enter a new nesting level for GUC values.  This is called at subtransaction
3761  * start and when entering a function that has proconfig settings.      NOTE that
3762  * we must not risk error here, else subtransaction start will be unhappy.
3763  */
3764 int
3765 NewGUCNestLevel(void)
3766 {
3767         return ++GUCNestLevel;
3768 }
3769
3770 /*
3771  * Do GUC processing at transaction or subtransaction commit or abort, or
3772  * when exiting a function that has proconfig settings.  (The name is thus
3773  * a bit of a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
3774  * During abort, we discard all GUC settings that were applied at nesting
3775  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
3776  */
3777 void
3778 AtEOXact_GUC(bool isCommit, int nestLevel)
3779 {
3780         bool            still_dirty;
3781         int                     i;
3782
3783         Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
3784
3785         /* Quick exit if nothing's changed in this transaction */
3786         if (!guc_dirty)
3787         {
3788                 GUCNestLevel = nestLevel - 1;
3789                 return;
3790         }
3791
3792         still_dirty = false;
3793         for (i = 0; i < num_guc_variables; i++)
3794         {
3795                 struct config_generic *gconf = guc_variables[i];
3796                 GucStack   *stack;
3797
3798                 /*
3799                  * Process and pop each stack entry within the nest level.      To
3800                  * simplify fmgr_security_definer(), we allow failure exit from a
3801                  * function-with-SET-options to be recovered at the surrounding
3802                  * transaction or subtransaction abort; so there could be more than
3803                  * one stack entry to pop.
3804                  */
3805                 while ((stack = gconf->stack) != NULL &&
3806                            stack->nest_level >= nestLevel)
3807                 {
3808                         GucStack   *prev = stack->prev;
3809                         bool            restorePrior = false;
3810                         bool            restoreMasked = false;
3811                         bool            changed;
3812
3813                         /*
3814                          * In this next bit, if we don't set either restorePrior or
3815                          * restoreMasked, we must "discard" any unwanted fields of the
3816                          * stack entries to avoid leaking memory.  If we do set one of
3817                          * those flags, unused fields will be cleaned up after restoring.
3818                          */
3819                         if (!isCommit)          /* if abort, always restore prior value */
3820                                 restorePrior = true;
3821                         else if (stack->state == GUC_SAVE)
3822                                 restorePrior = true;
3823                         else if (stack->nest_level == 1)
3824                         {
3825                                 /* transaction commit */
3826                                 if (stack->state == GUC_SET_LOCAL)
3827                                         restoreMasked = true;
3828                                 else if (stack->state == GUC_SET)
3829                                 {
3830                                         /* we keep the current active value */
3831                                         discard_stack_value(gconf, &stack->prior);
3832                                 }
3833                                 else    /* must be GUC_LOCAL */
3834                                         restorePrior = true;
3835                         }
3836                         else if (prev == NULL ||
3837                                          prev->nest_level < stack->nest_level - 1)
3838                         {
3839                                 /* decrement entry's level and do not pop it */
3840                                 stack->nest_level--;
3841                                 continue;
3842                         }
3843                         else
3844                         {
3845                                 /*
3846                                  * We have to merge this stack entry into prev. See README for
3847                                  * discussion of this bit.
3848                                  */
3849                                 switch (stack->state)
3850                                 {
3851                                         case GUC_SAVE:
3852                                                 Assert(false);  /* can't get here */
3853
3854                                         case GUC_SET:
3855                                                 /* next level always becomes SET */
3856                                                 discard_stack_value(gconf, &stack->prior);
3857                                                 if (prev->state == GUC_SET_LOCAL)
3858                                                         discard_stack_value(gconf, &prev->masked);
3859                                                 prev->state = GUC_SET;
3860                                                 break;
3861
3862                                         case GUC_LOCAL:
3863                                                 if (prev->state == GUC_SET)
3864                                                 {
3865                                                         /* LOCAL migrates down */
3866                                                         prev->masked = stack->prior;
3867                                                         prev->state = GUC_SET_LOCAL;
3868                                                 }
3869                                                 else
3870                                                 {
3871                                                         /* else just forget this stack level */
3872                                                         discard_stack_value(gconf, &stack->prior);
3873                                                 }
3874                                                 break;
3875
3876                                         case GUC_SET_LOCAL:
3877                                                 /* prior state at this level no longer wanted */
3878                                                 discard_stack_value(gconf, &stack->prior);
3879                                                 /* copy down the masked state */
3880                                                 if (prev->state == GUC_SET_LOCAL)
3881                                                         discard_stack_value(gconf, &prev->masked);
3882                                                 prev->masked = stack->masked;
3883                                                 prev->state = GUC_SET_LOCAL;
3884                                                 break;
3885                                 }
3886                         }
3887
3888                         changed = false;
3889
3890                         if (restorePrior || restoreMasked)
3891                         {
3892                                 /* Perform appropriate restoration of the stacked value */
3893                                 union config_var_value newvalue;
3894                                 GucSource       newsource;
3895
3896                                 if (restoreMasked)
3897                                 {
3898                                         newvalue = stack->masked;
3899                                         newsource = PGC_S_SESSION;
3900                                 }
3901                                 else
3902                                 {
3903                                         newvalue = stack->prior;
3904                                         newsource = stack->source;
3905                                 }
3906
3907                                 switch (gconf->vartype)
3908                                 {
3909                                         case PGC_BOOL:
3910                                                 {
3911                                                         struct config_bool *conf = (struct config_bool *) gconf;
3912                                                         bool            newval = newvalue.boolval;
3913
3914                                                         if (*conf->variable != newval)
3915                                                         {
3916                                                                 if (conf->assign_hook)
3917                                                                         if (!(*conf->assign_hook) (newval,
3918                                                                                                            true, PGC_S_OVERRIDE))
3919                                                                                 elog(LOG, "failed to commit %s as %d",
3920                                                                                          conf->gen.name, (int) newval);
3921                                                                 *conf->variable = newval;
3922                                                                 changed = true;
3923                                                         }
3924                                                         break;
3925                                                 }
3926                                         case PGC_INT:
3927                                                 {
3928                                                         struct config_int *conf = (struct config_int *) gconf;
3929                                                         int                     newval = newvalue.intval;
3930
3931                                                         if (*conf->variable != newval)
3932                                                         {
3933                                                                 if (conf->assign_hook)
3934                                                                         if (!(*conf->assign_hook) (newval,
3935                                                                                                            true, PGC_S_OVERRIDE))
3936                                                                                 elog(LOG, "failed to commit %s as %d",
3937                                                                                          conf->gen.name, newval);
3938                                                                 *conf->variable = newval;
3939                                                                 changed = true;
3940                                                         }
3941                                                         break;
3942                                                 }
3943                                         case PGC_REAL:
3944                                                 {
3945                                                         struct config_real *conf = (struct config_real *) gconf;
3946                                                         double          newval = newvalue.realval;
3947
3948                                                         if (*conf->variable != newval)
3949                                                         {
3950                                                                 if (conf->assign_hook)
3951                                                                         if (!(*conf->assign_hook) (newval,
3952                                                                                                            true, PGC_S_OVERRIDE))
3953                                                                                 elog(LOG, "failed to commit %s as %g",
3954                                                                                          conf->gen.name, newval);
3955                                                                 *conf->variable = newval;
3956                                                                 changed = true;
3957                                                         }
3958                                                         break;
3959                                                 }
3960                                         case PGC_STRING:
3961                                                 {
3962                                                         struct config_string *conf = (struct config_string *) gconf;
3963                                                         char       *newval = newvalue.stringval;
3964
3965                                                         if (*conf->variable != newval)
3966                                                         {
3967                                                                 if (conf->assign_hook && newval)
3968                                                                 {
3969                                                                         const char *newstr;
3970
3971                                                                         newstr = (*conf->assign_hook) (newval, true,
3972                                                                                                                          PGC_S_OVERRIDE);
3973                                                                         if (newstr == NULL)
3974                                                                                 elog(LOG, "failed to commit %s as \"%s\"",
3975                                                                                          conf->gen.name, newval);
3976                                                                         else if (newstr != newval)
3977                                                                         {
3978                                                                                 /*
3979                                                                                  * If newval should now be freed,
3980                                                                                  * it'll be taken care of below.
3981                                                                                  *
3982                                                                                  * See notes in set_config_option
3983                                                                                  * about casting
3984                                                                                  */
3985                                                                                 newval = (char *) newstr;
3986                                                                         }
3987                                                                 }
3988
3989                                                                 set_string_field(conf, conf->variable, newval);
3990                                                                 changed = true;
3991                                                         }
3992
3993                                                         /*
3994                                                          * Release stacked values if not used anymore. We
3995                                                          * could use discard_stack_value() here, but since
3996                                                          * we have type-specific code anyway, might as
3997                                                          * well inline it.
3998                                                          */
3999                                                         set_string_field(conf, &stack->prior.stringval, NULL);
4000                                                         set_string_field(conf, &stack->masked.stringval, NULL);
4001                                                         break;
4002                                                 }
4003                                         case PGC_ENUM:
4004                                                 {
4005                                                         struct config_enum *conf = (struct config_enum *) gconf;
4006                                                         int newval = newvalue.enumval;
4007
4008                                                         if (*conf->variable != newval)
4009                                                         {
4010                                                                 if (conf->assign_hook)
4011                                                                         if (!(*conf->assign_hook) (newval,
4012                                                                                                                            true, PGC_S_OVERRIDE))
4013                                                                                 elog(LOG, "failed to commit %s as %s",
4014                                                                                          conf->gen.name,
4015                                                                                          config_enum_lookup_by_value(conf, newval));
4016                                                                 *conf->variable = newval;
4017                                                                 changed = true;
4018                                                         }
4019                                                         break;
4020                                                 }
4021                                 }
4022
4023                                 gconf->source = newsource;
4024                         }
4025
4026                         /* Finish popping the state stack */
4027                         gconf->stack = prev;
4028                         pfree(stack);
4029
4030                         /* Report new value if we changed it */
4031                         if (changed && (gconf->flags & GUC_REPORT))
4032                                 ReportGUCOption(gconf);
4033                 }                                               /* end of stack-popping loop */
4034
4035                 if (stack != NULL)
4036                         still_dirty = true;
4037         }
4038
4039         /* If there are no remaining stack entries, we can reset guc_dirty */
4040         guc_dirty = still_dirty;
4041
4042         /* Update nesting level */
4043         GUCNestLevel = nestLevel - 1;
4044 }
4045
4046
4047 /*
4048  * Start up automatic reporting of changes to variables marked GUC_REPORT.
4049  * This is executed at completion of backend startup.
4050  */
4051 void
4052 BeginReportingGUCOptions(void)
4053 {
4054         int                     i;
4055
4056         /*
4057          * Don't do anything unless talking to an interactive frontend of protocol
4058          * 3.0 or later.
4059          */
4060         if (whereToSendOutput != DestRemote ||
4061                 PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
4062                 return;
4063
4064         reporting_enabled = true;
4065
4066         /* Transmit initial values of interesting variables */
4067         for (i = 0; i < num_guc_variables; i++)
4068         {
4069                 struct config_generic *conf = guc_variables[i];
4070
4071                 if (conf->flags & GUC_REPORT)
4072                         ReportGUCOption(conf);
4073         }
4074 }
4075
4076 /*
4077  * ReportGUCOption: if appropriate, transmit option value to frontend
4078  */
4079 static void
4080 ReportGUCOption(struct config_generic * record)
4081 {
4082         if (reporting_enabled && (record->flags & GUC_REPORT))
4083         {
4084                 char       *val = _ShowOption(record, false);
4085                 StringInfoData msgbuf;
4086
4087                 pq_beginmessage(&msgbuf, 'S');
4088                 pq_sendstring(&msgbuf, record->name);
4089                 pq_sendstring(&msgbuf, val);
4090                 pq_endmessage(&msgbuf);
4091
4092                 pfree(val);
4093         }
4094 }
4095
4096 /*
4097  * Try to parse value as an integer.  The accepted formats are the
4098  * usual decimal, octal, or hexadecimal formats, optionally followed by
4099  * a unit name if "flags" indicates a unit is allowed.
4100  *
4101  * If the string parses okay, return true, else false.
4102  * If okay and result is not NULL, return the value in *result.
4103  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
4104  *      HINT message, or NULL if no hint provided.
4105  */
4106 bool
4107 parse_int(const char *value, int *result, int flags, const char **hintmsg)
4108 {
4109         int64           val;
4110         char       *endptr;
4111
4112         /* To suppress compiler warnings, always set output params */
4113         if (result)
4114                 *result = 0;
4115         if (hintmsg)
4116                 *hintmsg = NULL;
4117
4118         /* We assume here that int64 is at least as wide as long */
4119         errno = 0;
4120         val = strtol(value, &endptr, 0);
4121
4122         if (endptr == value)
4123                 return false;                   /* no HINT for integer syntax error */
4124
4125         if (errno == ERANGE || val != (int64) ((int32) val))
4126         {
4127                 if (hintmsg)
4128                         *hintmsg = gettext_noop("Value exceeds integer range.");
4129                 return false;
4130         }
4131
4132         /* allow whitespace between integer and unit */
4133         while (isspace((unsigned char) *endptr))
4134                 endptr++;
4135
4136         /* Handle possible unit */
4137         if (*endptr != '\0')
4138         {
4139                 /*
4140                  * Note: the multiple-switch coding technique here is a bit tedious,
4141                  * but seems necessary to avoid intermediate-value overflows.
4142                  *
4143                  * If INT64_IS_BUSTED (ie, it's really int32) we will fail to detect
4144                  * overflow due to units conversion, but there are few enough such
4145                  * machines that it does not seem worth trying to be smarter.
4146                  */
4147                 if (flags & GUC_UNIT_MEMORY)
4148                 {
4149                         /* Set hint for use if no match or trailing garbage */
4150                         if (hintmsg)
4151                                 *hintmsg = gettext_noop("Valid units for this parameter are \"kB\", \"MB\", and \"GB\".");
4152
4153 #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
4154 #error BLCKSZ must be between 1KB and 1MB
4155 #endif
4156 #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
4157 #error XLOG_BLCKSZ must be between 1KB and 1MB
4158 #endif
4159
4160                         if (strncmp(endptr, "kB", 2) == 0)
4161                         {
4162                                 endptr += 2;
4163                                 switch (flags & GUC_UNIT_MEMORY)
4164                                 {
4165                                         case GUC_UNIT_BLOCKS:
4166                                                 val /= (BLCKSZ / 1024);
4167                                                 break;
4168                                         case GUC_UNIT_XBLOCKS:
4169                                                 val /= (XLOG_BLCKSZ / 1024);
4170                                                 break;
4171                                 }
4172                         }
4173                         else if (strncmp(endptr, "MB", 2) == 0)
4174                         {
4175                                 endptr += 2;
4176                                 switch (flags & GUC_UNIT_MEMORY)
4177                                 {
4178                                         case GUC_UNIT_KB:
4179                                                 val *= KB_PER_MB;
4180                                                 break;
4181                                         case GUC_UNIT_BLOCKS:
4182                                                 val *= KB_PER_MB / (BLCKSZ / 1024);
4183                                                 break;
4184                                         case GUC_UNIT_XBLOCKS:
4185                                                 val *= KB_PER_MB / (XLOG_BLCKSZ / 1024);
4186                                                 break;
4187                                 }
4188                         }
4189                         else if (strncmp(endptr, "GB", 2) == 0)
4190                         {
4191                                 endptr += 2;
4192                                 switch (flags & GUC_UNIT_MEMORY)
4193                                 {
4194                                         case GUC_UNIT_KB:
4195                                                 val *= KB_PER_GB;
4196                                                 break;
4197                                         case GUC_UNIT_BLOCKS:
4198                                                 val *= KB_PER_GB / (BLCKSZ / 1024);
4199                                                 break;
4200                                         case GUC_UNIT_XBLOCKS:
4201                                                 val *= KB_PER_GB / (XLOG_BLCKSZ / 1024);
4202                                                 break;
4203                                 }
4204                         }
4205                 }
4206                 else if (flags & GUC_UNIT_TIME)
4207                 {
4208                         /* Set hint for use if no match or trailing garbage */
4209                         if (hintmsg)
4210                                 *hintmsg = gettext_noop("Valid units for this parameter are \"ms\", \"s\", \"min\", \"h\", and \"d\".");
4211
4212                         if (strncmp(endptr, "ms", 2) == 0)
4213                         {
4214                                 endptr += 2;
4215                                 switch (flags & GUC_UNIT_TIME)
4216                                 {
4217                                         case GUC_UNIT_S:
4218                                                 val /= MS_PER_S;
4219                                                 break;
4220                                         case GUC_UNIT_MIN:
4221                                                 val /= MS_PER_MIN;
4222                                                 break;
4223                                 }
4224                         }
4225                         else if (strncmp(endptr, "s", 1) == 0)
4226                         {
4227                                 endptr += 1;
4228                                 switch (flags & GUC_UNIT_TIME)
4229                                 {
4230                                         case GUC_UNIT_MS:
4231                                                 val *= MS_PER_S;
4232                                                 break;
4233                                         case GUC_UNIT_MIN:
4234                                                 val /= S_PER_MIN;
4235                                                 break;
4236                                 }
4237                         }
4238                         else if (strncmp(endptr, "min", 3) == 0)
4239                         {
4240                                 endptr += 3;
4241                                 switch (flags & GUC_UNIT_TIME)
4242                                 {
4243                                         case GUC_UNIT_MS:
4244                                                 val *= MS_PER_MIN;
4245                                                 break;
4246                                         case GUC_UNIT_S:
4247                                                 val *= S_PER_MIN;
4248                                                 break;
4249                                 }
4250                         }
4251                         else if (strncmp(endptr, "h", 1) == 0)
4252                         {
4253                                 endptr += 1;
4254                                 switch (flags & GUC_UNIT_TIME)
4255                                 {
4256                                         case GUC_UNIT_MS:
4257                                                 val *= MS_PER_H;
4258                                                 break;
4259                                         case GUC_UNIT_S:
4260                                                 val *= S_PER_H;
4261                                                 break;
4262                                         case GUC_UNIT_MIN:
4263                                                 val *= MIN_PER_H;
4264                                                 break;
4265                                 }
4266                         }
4267                         else if (strncmp(endptr, "d", 1) == 0)
4268                         {
4269                                 endptr += 1;
4270                                 switch (flags & GUC_UNIT_TIME)
4271                                 {
4272                                         case GUC_UNIT_MS:
4273                                                 val *= MS_PER_D;
4274                                                 break;
4275                                         case GUC_UNIT_S:
4276                                                 val *= S_PER_D;
4277                                                 break;
4278                                         case GUC_UNIT_MIN:
4279                                                 val *= MIN_PER_D;
4280                                                 break;
4281                                 }
4282                         }
4283                 }
4284
4285                 /* allow whitespace after unit */
4286                 while (isspace((unsigned char) *endptr))
4287                         endptr++;
4288
4289                 if (*endptr != '\0')
4290                         return false;           /* appropriate hint, if any, already set */
4291
4292                 /* Check for overflow due to units conversion */
4293                 if (val != (int64) ((int32) val))
4294                 {
4295                         if (hintmsg)
4296                                 *hintmsg = gettext_noop("Value exceeds integer range.");
4297                         return false;
4298                 }
4299         }
4300
4301         if (result)
4302                 *result = (int) val;
4303         return true;
4304 }
4305
4306
4307
4308 /*
4309  * Try to parse value as a floating point number in the usual format.
4310  * If the string parses okay, return true, else false.
4311  * If okay and result is not NULL, return the value in *result.
4312  */
4313 bool
4314 parse_real(const char *value, double *result)
4315 {
4316         double          val;
4317         char       *endptr;
4318
4319         if (result)
4320                 *result = 0;                    /* suppress compiler warning */
4321
4322         errno = 0;
4323         val = strtod(value, &endptr);
4324         if (endptr == value || errno == ERANGE)
4325                 return false;
4326
4327         /* allow whitespace after number */
4328         while (isspace((unsigned char) *endptr))
4329                 endptr++;
4330         if (*endptr != '\0')
4331                 return false;
4332
4333         if (result)
4334                 *result = val;
4335         return true;
4336 }
4337
4338
4339 /*
4340  * Lookup the name for an enum option with the selected value.
4341  * Should only ever be called with known-valid values, so throws
4342  * an elog(ERROR) if the enum option is not found.
4343  *
4344  * The returned string is a pointer to static data and not
4345  * allocated for modification.
4346  */
4347 const char *
4348 config_enum_lookup_by_value(struct config_enum *record, int val)
4349 {
4350         const struct config_enum_entry *entry;
4351
4352         for (entry = record->options; entry && entry->name; entry++)
4353         {
4354                 if (entry->val == val)
4355                         return entry->name;
4356         }
4357
4358         elog(ERROR, "could not find enum option %d for %s",
4359                  val, record->gen.name);
4360         return NULL;            /* silence compiler */
4361 }
4362
4363
4364 /*
4365  * Lookup the value for an enum option with the selected name
4366  * (case-insensitive).
4367  * If the enum option is found, sets the retval value and returns
4368  * true. If it's not found, return FALSE and retval is set to 0.
4369  */
4370 bool
4371 config_enum_lookup_by_name(struct config_enum *record, const char *value,
4372                                                    int *retval)
4373 {
4374         const struct config_enum_entry *entry;
4375
4376         for (entry = record->options; entry && entry->name; entry++)
4377         {
4378                 if (pg_strcasecmp(value, entry->name) == 0)
4379                 {
4380                         *retval = entry->val;
4381                         return TRUE;
4382                 }
4383         }
4384
4385         *retval = 0;
4386         return FALSE;
4387 }
4388
4389
4390 /*
4391  * Return a list of all available options for an enum, excluding
4392  * hidden ones, separated by the given separator.
4393  * If prefix is non-NULL, it is added before the first enum value.
4394  * If suffix is non-NULL, it is added to the end of the string.
4395  */
4396 static char *
4397 config_enum_get_options(struct config_enum *record, const char *prefix,
4398                                                 const char *suffix, const char *separator)
4399 {
4400         const struct config_enum_entry *entry;
4401         StringInfoData  retstr;
4402         int                     seplen;
4403
4404         initStringInfo(&retstr);
4405         appendStringInfoString(&retstr, prefix);
4406
4407         seplen = strlen(separator);
4408         for (entry = record->options; entry && entry->name; entry++)
4409         {
4410                 if (!entry->hidden)
4411                 {
4412                         appendStringInfoString(&retstr, entry->name);
4413                         appendBinaryStringInfo(&retstr, separator, seplen);
4414                 }
4415         }
4416
4417         /*
4418          * All the entries may have been hidden, leaving the string empty
4419          * if no prefix was given. This indicates a broken GUC setup, since
4420          * there is no use for an enum without any values, so we just check
4421          * to make sure we don't write to invalid memory instead of actually
4422          * trying to do something smart with it.
4423          */
4424         if (retstr.len >= seplen)
4425         {
4426                 /* Replace final separator */
4427                 retstr.data[retstr.len - seplen] = '\0';
4428                 retstr.len -= seplen;
4429         }
4430
4431         appendStringInfoString(&retstr, suffix);
4432
4433         return retstr.data;
4434 }
4435
4436 /*
4437  * Call a GucStringAssignHook function, being careful to free the
4438  * "newval" string if the hook ereports.
4439  *
4440  * This is split out of set_config_option just to avoid the "volatile"
4441  * qualifiers that would otherwise have to be plastered all over.
4442  */
4443 static const char *
4444 call_string_assign_hook(GucStringAssignHook assign_hook,
4445                                                 char *newval, bool doit, GucSource source)
4446 {
4447         const char *result;
4448
4449         PG_TRY();
4450         {
4451                 result = (*assign_hook) (newval, doit, source);
4452         }
4453         PG_CATCH();
4454         {
4455                 free(newval);
4456                 PG_RE_THROW();
4457         }
4458         PG_END_TRY();
4459
4460         return result;
4461 }
4462
4463
4464 /*
4465  * Sets option `name' to given value. The value should be a string
4466  * which is going to be parsed and converted to the appropriate data
4467  * type.  The context and source parameters indicate in which context this
4468  * function is being called so it can apply the access restrictions
4469  * properly.
4470  *
4471  * If value is NULL, set the option to its default value (normally the
4472  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
4473  *
4474  * action indicates whether to set the value globally in the session, locally
4475  * to the current top transaction, or just for the duration of a function call.
4476  *
4477  * If changeVal is false then don't really set the option but do all
4478  * the checks to see if it would work.
4479  *
4480  * If there is an error (non-existing option, invalid value) then an
4481  * ereport(ERROR) is thrown *unless* this is called in a context where we
4482  * don't want to ereport (currently, startup or SIGHUP config file reread).
4483  * In that case we write a suitable error message via ereport(LOG) and
4484  * return false. This is working around the deficiencies in the ereport
4485  * mechanism, so don't blame me.  In all other cases, the function
4486  * returns true, including cases where the input is valid but we chose
4487  * not to apply it because of context or source-priority considerations.
4488  *
4489  * See also SetConfigOption for an external interface.
4490  */
4491 bool
4492 set_config_option(const char *name, const char *value,
4493                                   GucContext context, GucSource source,
4494                                   GucAction action, bool changeVal)
4495 {
4496         struct config_generic *record;
4497         int                     elevel;
4498         bool            makeDefault;
4499
4500         if (context == PGC_SIGHUP || source == PGC_S_DEFAULT)
4501         {
4502                 /*
4503                  * To avoid cluttering the log, only the postmaster bleats loudly
4504                  * about problems with the config file.
4505                  */
4506                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
4507         }
4508         else if (source == PGC_S_DATABASE || source == PGC_S_USER)
4509                 elevel = WARNING;
4510         else
4511                 elevel = ERROR;
4512
4513         record = find_option(name, true, elevel);
4514         if (record == NULL)
4515         {
4516                 ereport(elevel,
4517                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
4518                            errmsg("unrecognized configuration parameter \"%s\"", name)));
4519                 return false;
4520         }
4521
4522         /*
4523          * If source is postgresql.conf, mark the found record with
4524          * GUC_IS_IN_FILE. This is for the convenience of ProcessConfigFile.  Note
4525          * that we do it even if changeVal is false, since ProcessConfigFile wants
4526          * the marking to occur during its testing pass.
4527          */
4528         if (source == PGC_S_FILE)
4529                 record->status |= GUC_IS_IN_FILE;
4530
4531         /*
4532          * Check if the option can be set at this time. See guc.h for the precise
4533          * rules. Note that we don't want to throw errors if we're in the SIGHUP
4534          * context. In that case we just ignore the attempt and return true.
4535          */
4536         switch (record->context)
4537         {
4538                 case PGC_INTERNAL:
4539                         if (context == PGC_SIGHUP)
4540                                 return true;
4541                         if (context != PGC_INTERNAL)
4542                         {
4543                                 ereport(elevel,
4544                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4545                                                  errmsg("parameter \"%s\" cannot be changed",
4546                                                                 name)));
4547                                 return false;
4548                         }
4549                         break;
4550                 case PGC_POSTMASTER:
4551                         if (context == PGC_SIGHUP)
4552                         {
4553                                 /*
4554                                  * We are reading a PGC_POSTMASTER var from postgresql.conf.
4555                                  * We can't change the setting, so give a warning if the DBA
4556                                  * tries to change it.  (Throwing an error would be more
4557                                  * consistent, but seems overly rigid.)
4558                                  */
4559                                 if (changeVal && !is_newvalue_equal(record, value))
4560                                         ereport(elevel,
4561                                                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4562                                                          errmsg("attempted change of parameter \"%s\" ignored",
4563                                                                         name),
4564                                                          errdetail("This parameter cannot be changed after server start.")));
4565                                 return true;
4566                         }
4567                         if (context != PGC_POSTMASTER)
4568                         {
4569                                 ereport(elevel,
4570                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4571                                                  errmsg("attempted change of parameter \"%s\" ignored",
4572                                                                 name),
4573                                                  errdetail("This parameter cannot be changed after server start.")));
4574                                 return false;
4575                         }
4576                         break;
4577                 case PGC_SIGHUP:
4578                         if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
4579                         {
4580                                 ereport(elevel,
4581                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4582                                                  errmsg("parameter \"%s\" cannot be changed now",
4583                                                                 name)));
4584                                 return false;
4585                         }
4586
4587                         /*
4588                          * Hmm, the idea of the SIGHUP context is "ought to be global, but
4589                          * can be changed after postmaster start". But there's nothing
4590                          * that prevents a crafty administrator from sending SIGHUP
4591                          * signals to individual backends only.
4592                          */
4593                         break;
4594                 case PGC_BACKEND:
4595                         if (context == PGC_SIGHUP)
4596                         {
4597                                 /*
4598                                  * If a PGC_BACKEND parameter is changed in the config file,
4599                                  * we want to accept the new value in the postmaster (whence
4600                                  * it will propagate to subsequently-started backends), but
4601                                  * ignore it in existing backends.      This is a tad klugy, but
4602                                  * necessary because we don't re-read the config file during
4603                                  * backend start.
4604                                  */
4605                                 if (IsUnderPostmaster)
4606                                         return true;
4607                         }
4608                         else if (context != PGC_BACKEND && context != PGC_POSTMASTER)
4609                         {
4610                                 ereport(elevel,
4611                                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
4612                                                  errmsg("parameter \"%s\" cannot be set after connection start",
4613                                                                 name)));
4614                                 return false;
4615                         }
4616                         break;
4617                 case PGC_SUSET:
4618                         if (context == PGC_USERSET || context == PGC_BACKEND)
4619                         {
4620                                 ereport(elevel,
4621                                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
4622                                                  errmsg("permission denied to set parameter \"%s\"",
4623                                                                 name)));
4624                                 return false;
4625                         }
4626                         break;
4627                 case PGC_USERSET:
4628                         /* always okay */
4629                         break;
4630         }
4631
4632         /*
4633          * Should we set reset/stacked values?  (If so, the behavior is not
4634          * transactional.)      This is done either when we get a default value from
4635          * the database's/user's/client's default settings or when we reset a
4636          * value to its default.
4637          */
4638         makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
4639                 ((value != NULL) || source == PGC_S_DEFAULT);
4640
4641         /*
4642          * Ignore attempted set if overridden by previously processed setting.
4643          * However, if changeVal is false then plow ahead anyway since we are
4644          * trying to find out if the value is potentially good, not actually use
4645          * it. Also keep going if makeDefault is true, since we may want to set
4646          * the reset/stacked values even if we can't set the variable itself.
4647          */
4648         if (record->source > source)
4649         {
4650                 if (changeVal && !makeDefault)
4651                 {
4652                         elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
4653                                  name);
4654                         return true;
4655                 }
4656                 changeVal = false;
4657         }
4658
4659         /*
4660          * Evaluate value and set variable.
4661          */
4662         switch (record->vartype)
4663         {
4664                 case PGC_BOOL:
4665                         {
4666                                 struct config_bool *conf = (struct config_bool *) record;
4667                                 bool            newval;
4668
4669                                 if (value)
4670                                 {
4671                                         if (!parse_bool(value, &newval))
4672                                         {
4673                                                 ereport(elevel,
4674                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4675                                                   errmsg("parameter \"%s\" requires a Boolean value",
4676                                                                  name)));
4677                                                 return false;
4678                                         }
4679                                 }
4680                                 else if (source == PGC_S_DEFAULT)
4681                                         newval = conf->boot_val;
4682                                 else
4683                                 {
4684                                         newval = conf->reset_val;
4685                                         source = conf->gen.reset_source;
4686                                 }
4687
4688                                 /* Save old value to support transaction abort */
4689                                 if (changeVal && !makeDefault)
4690                                         push_old_value(&conf->gen, action);
4691
4692                                 if (conf->assign_hook)
4693                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4694                                         {
4695                                                 ereport(elevel,
4696                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4697                                                          errmsg("invalid value for parameter \"%s\": %d",
4698                                                                         name, (int) newval)));
4699                                                 return false;
4700                                         }
4701
4702                                 if (changeVal)
4703                                 {
4704                                         *conf->variable = newval;
4705                                         conf->gen.source = source;
4706                                 }
4707                                 if (makeDefault)
4708                                 {
4709                                         GucStack   *stack;
4710
4711                                         if (conf->gen.reset_source <= source)
4712                                         {
4713                                                 conf->reset_val = newval;
4714                                                 conf->gen.reset_source = source;
4715                                         }
4716                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4717                                         {
4718                                                 if (stack->source <= source)
4719                                                 {
4720                                                         stack->prior.boolval = newval;
4721                                                         stack->source = source;
4722                                                 }
4723                                         }
4724                                 }
4725                                 break;
4726                         }
4727
4728                 case PGC_INT:
4729                         {
4730                                 struct config_int *conf = (struct config_int *) record;
4731                                 int                     newval;
4732
4733                                 if (value)
4734                                 {
4735                                         const char *hintmsg;
4736
4737                                         if (!parse_int(value, &newval, conf->gen.flags, &hintmsg))
4738                                         {
4739                                                 ereport(elevel,
4740                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4741                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4742                                                                 name, value),
4743                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
4744                                                 return false;
4745                                         }
4746                                         if (newval < conf->min || newval > conf->max)
4747                                         {
4748                                                 ereport(elevel,
4749                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4750                                                                  errmsg("%d is outside the valid range for parameter \"%s\" (%d .. %d)",
4751                                                                                 newval, name, conf->min, conf->max)));
4752                                                 return false;
4753                                         }
4754                                 }
4755                                 else if (source == PGC_S_DEFAULT)
4756                                         newval = conf->boot_val;
4757                                 else
4758                                 {
4759                                         newval = conf->reset_val;
4760                                         source = conf->gen.reset_source;
4761                                 }
4762
4763                                 /* Save old value to support transaction abort */
4764                                 if (changeVal && !makeDefault)
4765                                         push_old_value(&conf->gen, action);
4766
4767                                 if (conf->assign_hook)
4768                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4769                                         {
4770                                                 ereport(elevel,
4771                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4772                                                          errmsg("invalid value for parameter \"%s\": %d",
4773                                                                         name, newval)));
4774                                                 return false;
4775                                         }
4776
4777                                 if (changeVal)
4778                                 {
4779                                         *conf->variable = newval;
4780                                         conf->gen.source = source;
4781                                 }
4782                                 if (makeDefault)
4783                                 {
4784                                         GucStack   *stack;
4785
4786                                         if (conf->gen.reset_source <= source)
4787                                         {
4788                                                 conf->reset_val = newval;
4789                                                 conf->gen.reset_source = source;
4790                                         }
4791                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4792                                         {
4793                                                 if (stack->source <= source)
4794                                                 {
4795                                                         stack->prior.intval = newval;
4796                                                         stack->source = source;
4797                                                 }
4798                                         }
4799                                 }
4800                                 break;
4801                         }
4802
4803                 case PGC_REAL:
4804                         {
4805                                 struct config_real *conf = (struct config_real *) record;
4806                                 double          newval;
4807
4808                                 if (value)
4809                                 {
4810                                         if (!parse_real(value, &newval))
4811                                         {
4812                                                 ereport(elevel,
4813                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4814                                                   errmsg("parameter \"%s\" requires a numeric value",
4815                                                                  name)));
4816                                                 return false;
4817                                         }
4818                                         if (newval < conf->min || newval > conf->max)
4819                                         {
4820                                                 ereport(elevel,
4821                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4822                                                                  errmsg("%g is outside the valid range for parameter \"%s\" (%g .. %g)",
4823                                                                                 newval, name, conf->min, conf->max)));
4824                                                 return false;
4825                                         }
4826                                 }
4827                                 else if (source == PGC_S_DEFAULT)
4828                                         newval = conf->boot_val;
4829                                 else
4830                                 {
4831                                         newval = conf->reset_val;
4832                                         source = conf->gen.reset_source;
4833                                 }
4834
4835                                 /* Save old value to support transaction abort */
4836                                 if (changeVal && !makeDefault)
4837                                         push_old_value(&conf->gen, action);
4838
4839                                 if (conf->assign_hook)
4840                                         if (!(*conf->assign_hook) (newval, changeVal, source))
4841                                         {
4842                                                 ereport(elevel,
4843                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4844                                                          errmsg("invalid value for parameter \"%s\": %g",
4845                                                                         name, newval)));
4846                                                 return false;
4847                                         }
4848
4849                                 if (changeVal)
4850                                 {
4851                                         *conf->variable = newval;
4852                                         conf->gen.source = source;
4853                                 }
4854                                 if (makeDefault)
4855                                 {
4856                                         GucStack   *stack;
4857
4858                                         if (conf->gen.reset_source <= source)
4859                                         {
4860                                                 conf->reset_val = newval;
4861                                                 conf->gen.reset_source = source;
4862                                         }
4863                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4864                                         {
4865                                                 if (stack->source <= source)
4866                                                 {
4867                                                         stack->prior.realval = newval;
4868                                                         stack->source = source;
4869                                                 }
4870                                         }
4871                                 }
4872                                 break;
4873                         }
4874
4875                 case PGC_STRING:
4876                         {
4877                                 struct config_string *conf = (struct config_string *) record;
4878                                 char       *newval;
4879
4880                                 if (value)
4881                                 {
4882                                         newval = guc_strdup(elevel, value);
4883                                         if (newval == NULL)
4884                                                 return false;
4885
4886                                         /*
4887                                          * The only sort of "parsing" check we need to do is apply
4888                                          * truncation if GUC_IS_NAME.
4889                                          */
4890                                         if (conf->gen.flags & GUC_IS_NAME)
4891                                                 truncate_identifier(newval, strlen(newval), true);
4892                                 }
4893                                 else if (source == PGC_S_DEFAULT)
4894                                 {
4895                                         if (conf->boot_val == NULL)
4896                                                 newval = NULL;
4897                                         else
4898                                         {
4899                                                 newval = guc_strdup(elevel, conf->boot_val);
4900                                                 if (newval == NULL)
4901                                                         return false;
4902                                         }
4903                                 }
4904                                 else
4905                                 {
4906                                         /*
4907                                          * We could possibly avoid strdup here, but easier to make
4908                                          * this case work the same as the normal assignment case;
4909                                          * note the possible free of newval below.
4910                                          */
4911                                         if (conf->reset_val == NULL)
4912                                                 newval = NULL;
4913                                         else
4914                                         {
4915                                                 newval = guc_strdup(elevel, conf->reset_val);
4916                                                 if (newval == NULL)
4917                                                         return false;
4918                                         }
4919                                         source = conf->gen.reset_source;
4920                                 }
4921
4922                                 /* Save old value to support transaction abort */
4923                                 if (changeVal && !makeDefault)
4924                                         push_old_value(&conf->gen, action);
4925
4926                                 if (conf->assign_hook && newval)
4927                                 {
4928                                         const char *hookresult;
4929
4930                                         /*
4931                                          * If the hook ereports, we have to make sure we free
4932                                          * newval, else it will be a permanent memory leak.
4933                                          */
4934                                         hookresult = call_string_assign_hook(conf->assign_hook,
4935                                                                                                                  newval,
4936                                                                                                                  changeVal,
4937                                                                                                                  source);
4938                                         if (hookresult == NULL)
4939                                         {
4940                                                 free(newval);
4941                                                 ereport(elevel,
4942                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
4943                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
4944                                                                 name, value ? value : "")));
4945                                                 return false;
4946                                         }
4947                                         else if (hookresult != newval)
4948                                         {
4949                                                 free(newval);
4950
4951                                                 /*
4952                                                  * Having to cast away const here is annoying, but the
4953                                                  * alternative is to declare assign_hooks as returning
4954                                                  * char*, which would mean they'd have to cast away
4955                                                  * const, or as both taking and returning char*, which
4956                                                  * doesn't seem attractive either --- we don't want
4957                                                  * them to scribble on the passed str.
4958                                                  */
4959                                                 newval = (char *) hookresult;
4960                                         }
4961                                 }
4962
4963                                 if (changeVal)
4964                                 {
4965                                         set_string_field(conf, conf->variable, newval);
4966                                         conf->gen.source = source;
4967                                 }
4968                                 if (makeDefault)
4969                                 {
4970                                         GucStack   *stack;
4971
4972                                         if (conf->gen.reset_source <= source)
4973                                         {
4974                                                 set_string_field(conf, &conf->reset_val, newval);
4975                                                 conf->gen.reset_source = source;
4976                                         }
4977                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
4978                                         {
4979                                                 if (stack->source <= source)
4980                                                 {
4981                                                         set_string_field(conf, &stack->prior.stringval,
4982                                                                                          newval);
4983                                                         stack->source = source;
4984                                                 }
4985                                         }
4986                                 }
4987                                 /* Perhaps we didn't install newval anywhere */
4988                                 if (newval && !string_field_used(conf, newval))
4989                                         free(newval);
4990                                 break;
4991                         }
4992                 case PGC_ENUM:
4993                         {
4994                                 struct config_enum *conf = (struct config_enum *) record;
4995                                 int                     newval;
4996
4997                                 if (value)
4998                                 {
4999                                         if (!config_enum_lookup_by_name(conf, value, &newval))
5000                                         {
5001                                                 char *hintmsg;
5002
5003                                                 hintmsg = config_enum_get_options(conf,
5004                                                                                                                   "Available values: ",
5005                                                                                                                   ".", ", ");
5006
5007                                                 ereport(elevel,
5008                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5009                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5010                                                                                 name, value),
5011                                                                  hintmsg ? errhint("%s", _(hintmsg)) : 0));
5012
5013                                                 if (hintmsg)
5014                                                         pfree(hintmsg);
5015                                                 return false;
5016                                         }
5017                                 }
5018                                 else if (source == PGC_S_DEFAULT)
5019                                         newval = conf->boot_val;
5020                                 else
5021                                 {
5022                                         newval = conf->reset_val;
5023                                         source = conf->gen.reset_source;
5024                                 }
5025
5026                                 /* Save old value to support transaction abort */
5027                                 if (changeVal && !makeDefault)
5028                                         push_old_value(&conf->gen, action);
5029
5030                                 if (conf->assign_hook)
5031                                         if (!(*conf->assign_hook) (newval, changeVal, source))
5032                                         {
5033                                                 ereport(elevel,
5034                                                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5035                                                                  errmsg("invalid value for parameter \"%s\": \"%s\"",
5036                                                                                 name,
5037                                                                                 config_enum_lookup_by_value(conf, newval))));
5038                                                 return false;
5039                                         }
5040
5041                                 if (changeVal)
5042                                 {
5043                                         *conf->variable = newval;
5044                                         conf->gen.source = source;
5045                                 }
5046                                 if (makeDefault)
5047                                 {
5048                                         GucStack   *stack;
5049
5050                                         if (conf->gen.reset_source <= source)
5051                                         {
5052                                                 conf->reset_val = newval;
5053                                                 conf->gen.reset_source = source;
5054                                         }
5055                                         for (stack = conf->gen.stack; stack; stack = stack->prev)
5056                                         {
5057                                                 if (stack->source <= source)
5058                                                 {
5059                                                         stack->prior.enumval = newval;
5060                                                         stack->source = source;
5061                                                 }
5062                                         }
5063                                 }
5064                                 break;
5065                         }
5066         }
5067
5068         if (changeVal && (record->flags & GUC_REPORT))
5069                 ReportGUCOption(record);
5070
5071         return true;
5072 }
5073
5074
5075 /*
5076  * Set the fields for source file and line number the setting came from.
5077  */
5078 static void
5079 set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
5080 {
5081         struct config_generic *record;
5082         int                     elevel;
5083
5084         /*
5085          * To avoid cluttering the log, only the postmaster bleats loudly
5086          * about problems with the config file.
5087          */
5088         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5089
5090         record = find_option(name, true, elevel);
5091         /* should not happen */
5092         if (record == NULL)
5093                 elog(ERROR, "unrecognized configuration parameter \"%s\"", name);
5094
5095         sourcefile = guc_strdup(elevel, sourcefile);
5096         if (record->sourcefile)
5097                 free(record->sourcefile);
5098         record->sourcefile = sourcefile;
5099         record->sourceline = sourceline;
5100 }
5101
5102 /*
5103  * Set a config option to the given value. See also set_config_option,
5104  * this is just the wrapper to be called from outside GUC.      NB: this
5105  * is used only for non-transactional operations.
5106  *
5107  * Note: there is no support here for setting source file/line, as it
5108  * is currently not needed.
5109  */
5110 void
5111 SetConfigOption(const char *name, const char *value,
5112                                 GucContext context, GucSource source)
5113 {
5114         (void) set_config_option(name, value, context, source,
5115                                                          GUC_ACTION_SET, true);
5116 }
5117
5118
5119
5120 /*
5121  * Fetch the current value of the option `name'. If the option doesn't exist,
5122  * throw an ereport and don't return.
5123  *
5124  * The string is *not* allocated for modification and is really only
5125  * valid until the next call to configuration related functions.
5126  */
5127 const char *
5128 GetConfigOption(const char *name)
5129 {
5130         struct config_generic *record;
5131         static char buffer[256];
5132
5133         record = find_option(name, false, ERROR);
5134         if (record == NULL)
5135                 ereport(ERROR,
5136                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5137                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5138         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5139                 ereport(ERROR,
5140                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5141                                  errmsg("must be superuser to examine \"%s\"", name)));
5142
5143         switch (record->vartype)
5144         {
5145                 case PGC_BOOL:
5146                         return *((struct config_bool *) record)->variable ? "on" : "off";
5147
5148                 case PGC_INT:
5149                         snprintf(buffer, sizeof(buffer), "%d",
5150                                          *((struct config_int *) record)->variable);
5151                         return buffer;
5152
5153                 case PGC_REAL:
5154                         snprintf(buffer, sizeof(buffer), "%g",
5155                                          *((struct config_real *) record)->variable);
5156                         return buffer;
5157
5158                 case PGC_STRING:
5159                         return *((struct config_string *) record)->variable;
5160
5161                 case PGC_ENUM:
5162                         return config_enum_lookup_by_value((struct config_enum *) record,
5163                                                                                         *((struct config_enum *) record)->variable);
5164         }
5165         return NULL;
5166 }
5167
5168 /*
5169  * Get the RESET value associated with the given option.
5170  *
5171  * Note: this is not re-entrant, due to use of static result buffer;
5172  * not to mention that a string variable could have its reset_val changed.
5173  * Beware of assuming the result value is good for very long.
5174  */
5175 const char *
5176 GetConfigOptionResetString(const char *name)
5177 {
5178         struct config_generic *record;
5179         static char buffer[256];
5180
5181         record = find_option(name, false, ERROR);
5182         if (record == NULL)
5183                 ereport(ERROR,
5184                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5185                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5186         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
5187                 ereport(ERROR,
5188                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
5189                                  errmsg("must be superuser to examine \"%s\"", name)));
5190
5191         switch (record->vartype)
5192         {
5193                 case PGC_BOOL:
5194                         return ((struct config_bool *) record)->reset_val ? "on" : "off";
5195
5196                 case PGC_INT:
5197                         snprintf(buffer, sizeof(buffer), "%d",
5198                                          ((struct config_int *) record)->reset_val);
5199                         return buffer;
5200
5201                 case PGC_REAL:
5202                         snprintf(buffer, sizeof(buffer), "%g",
5203                                          ((struct config_real *) record)->reset_val);
5204                         return buffer;
5205
5206                 case PGC_STRING:
5207                         return ((struct config_string *) record)->reset_val;
5208
5209                 case PGC_ENUM:
5210                         return config_enum_lookup_by_value((struct config_enum *) record,
5211                                                                                     ((struct config_enum *) record)->reset_val);
5212         }
5213         return NULL;
5214 }
5215
5216 /*
5217  * Detect whether the given configuration option can only be set by
5218  * a superuser.
5219  */
5220 bool
5221 IsSuperuserConfigOption(const char *name)
5222 {
5223         struct config_generic *record;
5224
5225         record = find_option(name, false, ERROR);
5226         /* On an unrecognized name, don't error, just return false. */
5227         if (record == NULL)
5228                 return false;
5229         return (record->context == PGC_SUSET);
5230 }
5231
5232
5233 /*
5234  * GUC_complaint_elevel
5235  *              Get the ereport error level to use in an assign_hook's error report.
5236  *
5237  * This should be used by assign hooks that want to emit a custom error
5238  * report (in addition to the generic "invalid value for option FOO" that
5239  * guc.c will provide).  Note that the result might be ERROR or a lower
5240  * level, so the caller must be prepared for control to return from ereport,
5241  * or not.  If control does return, return false/NULL from the hook function.
5242  *
5243  * At some point it'd be nice to replace this with a mechanism that allows
5244  * the custom message to become the DETAIL line of guc.c's generic message.
5245  */
5246 int
5247 GUC_complaint_elevel(GucSource source)
5248 {
5249         int                     elevel;
5250
5251         if (source == PGC_S_FILE)
5252         {
5253                 /*
5254                  * To avoid cluttering the log, only the postmaster bleats loudly
5255                  * about problems with the config file.
5256                  */
5257                 elevel = IsUnderPostmaster ? DEBUG3 : LOG;
5258         }
5259         else if (source == PGC_S_OVERRIDE)
5260         {
5261                 /*
5262                  * If we're a postmaster child, this is probably "undo" during
5263                  * transaction abort, so we don't want to clutter the log.  There's
5264                  * a small chance of a real problem with an OVERRIDE setting,
5265                  * though, so suppressing the message entirely wouldn't be desirable.
5266                  */
5267                 elevel = IsUnderPostmaster ? DEBUG5 : LOG;
5268         }
5269         else if (source < PGC_S_INTERACTIVE)
5270                 elevel = LOG;
5271         else
5272                 elevel = ERROR;
5273
5274         return elevel;
5275 }
5276
5277
5278 /*
5279  * flatten_set_variable_args
5280  *              Given a parsenode List as emitted by the grammar for SET,
5281  *              convert to the flat string representation used by GUC.
5282  *
5283  * We need to be told the name of the variable the args are for, because
5284  * the flattening rules vary (ugh).
5285  *
5286  * The result is NULL if args is NIL (ie, SET ... TO DEFAULT), otherwise
5287  * a palloc'd string.
5288  */
5289 static char *
5290 flatten_set_variable_args(const char *name, List *args)
5291 {
5292         struct config_generic *record;
5293         int                     flags;
5294         StringInfoData buf;
5295         ListCell   *l;
5296
5297         /* Fast path if just DEFAULT */
5298         if (args == NIL)
5299                 return NULL;
5300
5301         /* Else get flags for the variable */
5302         record = find_option(name, true, ERROR);
5303         if (record == NULL)
5304                 ereport(ERROR,
5305                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
5306                            errmsg("unrecognized configuration parameter \"%s\"", name)));
5307
5308         flags = record->flags;
5309
5310         /* Complain if list input and non-list variable */
5311         if ((flags & GUC_LIST_INPUT) == 0 &&
5312                 list_length(args) != 1)
5313                 ereport(ERROR,
5314                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
5315                                  errmsg("SET %s takes only one argument", name)));
5316
5317         initStringInfo(&buf);
5318
5319         /*
5320          * Each list member may be a plain A_Const node, or an A_Const within a
5321          * TypeCast; the latter case is supported only for ConstInterval
5322          * arguments (for SET TIME ZONE).
5323          */
5324         foreach(l, args)
5325         {
5326                 Node       *arg = (Node *) lfirst(l);
5327                 char       *val;
5328                 TypeName   *typename = NULL;
5329                 A_Const    *con;
5330
5331                 if (l != list_head(args))
5332                         appendStringInfo(&buf, ", ");
5333
5334                 if (IsA(arg, TypeCast))
5335                 {
5336                         TypeCast *tc = (TypeCast *) arg;
5337
5338                         arg = tc->arg;
5339                         typename = tc->typename;
5340                 }
5341
5342                 if (!IsA(arg, A_Const))
5343                         elog(ERROR, "unrecognized node type: %d", (int) nodeTag(arg));
5344                 con = (A_Const *) arg;
5345
5346                 switch (nodeTag(&con->val))
5347                 {
5348                         case T_Integer:
5349                                 appendStringInfo(&buf, "%ld", intVal(&con->val));
5350                                 break;
5351                         case T_Float:
5352                                 /* represented as a string, so just copy it */
5353                                 appendStringInfoString(&buf, strVal(&con->val));
5354                                 break;
5355                         case T_String:
5356                                 val = strVal(&con->val);
5357                                 if (typename != NULL)
5358                                 {
5359                                         /*
5360                                          * Must be a ConstInterval argument for TIME ZONE. Coerce
5361                                          * to interval and back to normalize the value and account
5362                                          * for any typmod.
5363                                          */
5364                                         Oid                     typoid;
5365                                         int32           typmod;
5366                                         Datum           interval;
5367                                         char       *intervalout;
5368
5369                                         typoid = typenameTypeId(NULL, typename, &typmod);
5370                                         Assert(typoid == INTERVALOID);
5371
5372                                         interval =
5373                                                 DirectFunctionCall3(interval_in,
5374                                                                                         CStringGetDatum(val),
5375                                                                                         ObjectIdGetDatum(InvalidOid),
5376                                                                                         Int32GetDatum(typmod));
5377
5378                                         intervalout =
5379                                                 DatumGetCString(DirectFunctionCall1(interval_out,
5380                                                                                                                         interval));
5381                                         appendStringInfo(&buf, "INTERVAL '%s'", intervalout);
5382                                 }
5383                                 else
5384                                 {
5385                                         /*
5386                                          * Plain string literal or identifier.  For quote mode,
5387                                          * quote it if it's not a vanilla identifier.
5388                                          */
5389                                         if (flags & GUC_LIST_QUOTE)
5390                                                 appendStringInfoString(&buf, quote_identifier(val));
5391                                         else
5392                                                 appendStringInfoString(&buf, val);
5393                                 }
5394                                 break;
5395                         default:
5396                                 elog(ERROR, "unrecognized node type: %d",
5397                                          (int) nodeTag(&con->val));
5398                                 break;
5399                 }
5400         }
5401
5402         return buf.data;
5403 }
5404
5405
5406 /*
5407  * SET command
5408  */
5409 void
5410 ExecSetVariableStmt(VariableSetStmt *stmt)
5411 {
5412         GucAction       action = stmt->is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET;
5413
5414         switch (stmt->kind)
5415         {
5416                 case VAR_SET_VALUE:
5417                 case VAR_SET_CURRENT:
5418                         set_config_option(stmt->name,
5419                                                           ExtractSetVariableArgs(stmt),
5420                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5421                                                           PGC_S_SESSION,
5422                                                           action,
5423                                                           true);
5424                         break;
5425                 case VAR_SET_MULTI:
5426
5427                         /*
5428                          * Special case for special SQL syntax that effectively sets more
5429                          * than one variable per statement.
5430                          */
5431                         if (strcmp(stmt->name, "TRANSACTION") == 0)
5432                         {
5433                                 ListCell   *head;
5434
5435                                 foreach(head, stmt->args)
5436                                 {
5437                                         DefElem    *item = (DefElem *) lfirst(head);
5438
5439                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5440                                                 SetPGVariable("transaction_isolation",
5441                                                                           list_make1(item->arg), stmt->is_local);
5442                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5443                                                 SetPGVariable("transaction_read_only",
5444                                                                           list_make1(item->arg), stmt->is_local);
5445                                         else
5446                                                 elog(ERROR, "unexpected SET TRANSACTION element: %s",
5447                                                          item->defname);
5448                                 }
5449                         }
5450                         else if (strcmp(stmt->name, "SESSION CHARACTERISTICS") == 0)
5451                         {
5452                                 ListCell   *head;
5453
5454                                 foreach(head, stmt->args)
5455                                 {
5456                                         DefElem    *item = (DefElem *) lfirst(head);
5457
5458                                         if (strcmp(item->defname, "transaction_isolation") == 0)
5459                                                 SetPGVariable("default_transaction_isolation",
5460                                                                           list_make1(item->arg), stmt->is_local);
5461                                         else if (strcmp(item->defname, "transaction_read_only") == 0)
5462                                                 SetPGVariable("default_transaction_read_only",
5463                                                                           list_make1(item->arg), stmt->is_local);
5464                                         else
5465                                                 elog(ERROR, "unexpected SET SESSION element: %s",
5466                                                          item->defname);
5467                                 }
5468                         }
5469                         else
5470                                 elog(ERROR, "unexpected SET MULTI element: %s",
5471                                          stmt->name);
5472                         break;
5473                 case VAR_SET_DEFAULT:
5474                 case VAR_RESET:
5475                         set_config_option(stmt->name,
5476                                                           NULL,
5477                                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5478                                                           PGC_S_SESSION,
5479                                                           action,
5480                                                           true);
5481                         break;
5482                 case VAR_RESET_ALL:
5483                         ResetAllOptions();
5484                         break;
5485         }
5486 }
5487
5488 /*
5489  * Get the value to assign for a VariableSetStmt, or NULL if it's RESET.
5490  * The result is palloc'd.
5491  *
5492  * This is exported for use by actions such as ALTER ROLE SET.
5493  */
5494 char *
5495 ExtractSetVariableArgs(VariableSetStmt *stmt)
5496 {
5497         switch (stmt->kind)
5498         {
5499                 case VAR_SET_VALUE:
5500                         return flatten_set_variable_args(stmt->name, stmt->args);
5501                 case VAR_SET_CURRENT:
5502                         return GetConfigOptionByName(stmt->name, NULL);
5503                 default:
5504                         return NULL;
5505         }
5506 }
5507
5508 /*
5509  * SetPGVariable - SET command exported as an easily-C-callable function.
5510  *
5511  * This provides access to SET TO value, as well as SET TO DEFAULT (expressed
5512  * by passing args == NIL), but not SET FROM CURRENT functionality.
5513  */
5514 void
5515 SetPGVariable(const char *name, List *args, bool is_local)
5516 {
5517         char       *argstring = flatten_set_variable_args(name, args);
5518
5519         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5520         set_config_option(name,
5521                                           argstring,
5522                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5523                                           PGC_S_SESSION,
5524                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5525                                           true);
5526 }
5527
5528 /*
5529  * SET command wrapped as a SQL callable function.
5530  */
5531 Datum
5532 set_config_by_name(PG_FUNCTION_ARGS)
5533 {
5534         char       *name;
5535         char       *value;
5536         char       *new_value;
5537         bool            is_local;
5538
5539         if (PG_ARGISNULL(0))
5540                 ereport(ERROR,
5541                                 (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
5542                                  errmsg("SET requires parameter name")));
5543
5544         /* Get the GUC variable name */
5545         name = TextDatumGetCString(PG_GETARG_DATUM(0));
5546
5547         /* Get the desired value or set to NULL for a reset request */
5548         if (PG_ARGISNULL(1))
5549                 value = NULL;
5550         else
5551                 value = TextDatumGetCString(PG_GETARG_DATUM(1));
5552
5553         /*
5554          * Get the desired state of is_local. Default to false if provided value
5555          * is NULL
5556          */
5557         if (PG_ARGISNULL(2))
5558                 is_local = false;
5559         else
5560                 is_local = PG_GETARG_BOOL(2);
5561
5562         /* Note SET DEFAULT (argstring == NULL) is equivalent to RESET */
5563         set_config_option(name,
5564                                           value,
5565                                           (superuser() ? PGC_SUSET : PGC_USERSET),
5566                                           PGC_S_SESSION,
5567                                           is_local ? GUC_ACTION_LOCAL : GUC_ACTION_SET,
5568                                           true);
5569
5570         /* get the new current value */
5571         new_value = GetConfigOptionByName(name, NULL);
5572
5573         /* Convert return string to text */
5574         PG_RETURN_TEXT_P(cstring_to_text(new_value));
5575 }
5576
5577
5578 /*
5579  * Common code for DefineCustomXXXVariable subroutines: allocate the
5580  * new variable's config struct and fill in generic fields.
5581  */
5582 static struct config_generic *
5583 init_custom_variable(const char *name,
5584                                          const char *short_desc,
5585                                          const char *long_desc,
5586                                          GucContext context,
5587                                          int flags,
5588                                          enum config_type type,
5589                                          size_t sz)
5590 {
5591         struct config_generic *gen;
5592
5593         /*
5594          * Only allow custom PGC_POSTMASTER variables to be created during
5595          * shared library preload; any later than that, we can't ensure that
5596          * the value doesn't change after startup.  This is a fatal elog if it
5597          * happens; just erroring out isn't safe because we don't know what
5598          * the calling loadable module might already have hooked into.
5599          */
5600         if (context == PGC_POSTMASTER &&
5601                 !process_shared_preload_libraries_in_progress)
5602                 elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
5603
5604         gen = (struct config_generic *) guc_malloc(ERROR, sz);
5605         memset(gen, 0, sz);
5606
5607         gen->name = guc_strdup(ERROR, name);
5608         gen->context = context;
5609         gen->group = CUSTOM_OPTIONS;
5610         gen->short_desc = short_desc;
5611         gen->long_desc = long_desc;
5612         gen->flags = flags;
5613         gen->vartype = type;
5614
5615         return gen;
5616 }
5617
5618 /*
5619  * Common code for DefineCustomXXXVariable subroutines: insert the new
5620  * variable into the GUC variable array, replacing any placeholder.
5621  */
5622 static void
5623 define_custom_variable(struct config_generic * variable)
5624 {
5625         const char *name = variable->name;
5626         const char **nameAddr = &name;
5627         const char *value;
5628         struct config_string *pHolder;
5629         GucContext phcontext;
5630         struct config_generic **res;
5631
5632         /*
5633          * See if there's a placeholder by the same name.
5634          */
5635         res = (struct config_generic **) bsearch((void *) &nameAddr,
5636                                                                                          (void *) guc_variables,
5637                                                                                          num_guc_variables,
5638                                                                                          sizeof(struct config_generic *),
5639                                                                                          guc_var_compare);
5640         if (res == NULL)
5641         {
5642                 /*
5643                  * No placeholder to replace, so we can just add it ... but first,
5644                  * make sure it's initialized to its default value.
5645                  */
5646                 InitializeOneGUCOption(variable);
5647                 add_guc_variable(variable, ERROR);
5648                 return;
5649         }
5650
5651         /*
5652          * This better be a placeholder
5653          */
5654         if (((*res)->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
5655                 ereport(ERROR,
5656                                 (errcode(ERRCODE_INTERNAL_ERROR),
5657                                  errmsg("attempt to redefine parameter \"%s\"", name)));
5658
5659         Assert((*res)->vartype == PGC_STRING);
5660         pHolder = (struct config_string *) (*res);
5661
5662         /*
5663          * First, set the variable to its default value.  We must do this even
5664          * though we intend to immediately apply a new value, since it's possible
5665          * that the new value is invalid.
5666          */
5667         InitializeOneGUCOption(variable);
5668
5669         /*
5670          * Replace the placeholder. We aren't changing the name, so no re-sorting
5671          * is necessary
5672          */
5673         *res = variable;
5674
5675         /*
5676          * Infer context for assignment based on source of existing value.
5677          * We can't tell this with exact accuracy, but we can at least do
5678          * something reasonable in typical cases.
5679          */
5680         switch (pHolder->gen.source)
5681         {
5682                 case PGC_S_DEFAULT:
5683                 case PGC_S_ENV_VAR:
5684                 case PGC_S_FILE:
5685                 case PGC_S_ARGV:
5686                         /*
5687                          * If we got past the check in init_custom_variable, we can
5688                          * safely assume that any existing value for a PGC_POSTMASTER
5689                          * variable was set in postmaster context.
5690                          */
5691                         if (variable->context == PGC_POSTMASTER)
5692                                 phcontext = PGC_POSTMASTER;
5693                         else
5694                                 phcontext = PGC_SIGHUP;
5695                         break;
5696                 case PGC_S_DATABASE:
5697                 case PGC_S_USER:
5698                 case PGC_S_CLIENT:
5699                 case PGC_S_SESSION:
5700                 default:
5701                         phcontext = PGC_USERSET;
5702                         break;
5703         }
5704
5705         /*
5706          * Assign the string value stored in the placeholder to the real variable.
5707          *
5708          * XXX this is not really good enough --- it should be a nontransactional
5709          * assignment, since we don't want it to roll back if the current xact
5710          * fails later.  (Or do we?)
5711          */
5712         value = *pHolder->variable;
5713
5714         if (value)
5715         {
5716                 if (set_config_option(name, value,
5717                                                           phcontext, pHolder->gen.source,
5718                                                           GUC_ACTION_SET, true))
5719                 {
5720                         /* Also copy over any saved source-location information */
5721                         if (pHolder->gen.sourcefile)
5722                                 set_config_sourcefile(name, pHolder->gen.sourcefile,
5723                                                                           pHolder->gen.sourceline);
5724                 }
5725         }
5726
5727         /*
5728          * Free up as much as we conveniently can of the placeholder structure
5729          * (this neglects any stack items...)
5730          */
5731         set_string_field(pHolder, pHolder->variable, NULL);
5732         set_string_field(pHolder, &pHolder->reset_val, NULL);
5733
5734         free(pHolder);
5735 }
5736
5737 void
5738 DefineCustomBoolVariable(const char *name,
5739                                                  const char *short_desc,
5740                                                  const char *long_desc,
5741                                                  bool *valueAddr,
5742                                                  bool bootValue,
5743                                                  GucContext context,
5744                                                  int flags,
5745                                                  GucBoolAssignHook assign_hook,
5746                                                  GucShowHook show_hook)
5747 {
5748         struct config_bool *var;
5749
5750         var = (struct config_bool *)
5751                 init_custom_variable(name, short_desc, long_desc, context, flags,
5752                                                          PGC_BOOL, sizeof(struct config_bool));
5753         var->variable = valueAddr;
5754         var->boot_val = bootValue;
5755         var->reset_val = bootValue;
5756         var->assign_hook = assign_hook;
5757         var->show_hook = show_hook;
5758         define_custom_variable(&var->gen);
5759 }
5760
5761 void
5762 DefineCustomIntVariable(const char *name,
5763                                                 const char *short_desc,
5764                                                 const char *long_desc,
5765                                                 int *valueAddr,
5766                                                 int bootValue,
5767                                                 int minValue,
5768                                                 int maxValue,
5769                                                 GucContext context,
5770                                                 int flags,
5771                                                 GucIntAssignHook assign_hook,
5772                                                 GucShowHook show_hook)
5773 {
5774         struct config_int *var;
5775
5776         var = (struct config_int *)
5777                 init_custom_variable(name, short_desc, long_desc, context, flags,
5778                                                          PGC_INT, sizeof(struct config_int));
5779         var->variable = valueAddr;
5780         var->boot_val = bootValue;
5781         var->reset_val = bootValue;
5782         var->min = minValue;
5783         var->max = maxValue;
5784         var->assign_hook = assign_hook;
5785         var->show_hook = show_hook;
5786         define_custom_variable(&var->gen);
5787 }
5788
5789 void
5790 DefineCustomRealVariable(const char *name,
5791                                                  const char *short_desc,
5792                                                  const char *long_desc,
5793                                                  double *valueAddr,
5794                                                  double bootValue,
5795                                                  double minValue,
5796                                                  double maxValue,
5797                                                  GucContext context,
5798                                                  int flags,
5799                                                  GucRealAssignHook assign_hook,
5800                                                  GucShowHook show_hook)
5801 {
5802         struct config_real *var;
5803
5804         var = (struct config_real *)
5805                 init_custom_variable(name, short_desc, long_desc, context, flags,
5806                                                          PGC_REAL, sizeof(struct config_real));
5807         var->variable = valueAddr;
5808         var->boot_val = bootValue;
5809         var->reset_val = bootValue;
5810         var->min = minValue;
5811         var->max = maxValue;
5812         var->assign_hook = assign_hook;
5813         var->show_hook = show_hook;
5814         define_custom_variable(&var->gen);
5815 }
5816
5817 void
5818 DefineCustomStringVariable(const char *name,
5819                                                    const char *short_desc,
5820                                                    const char *long_desc,
5821                                                    char **valueAddr,
5822                                                    const char *bootValue,
5823                                                    GucContext context,
5824                                                    int flags,
5825                                                    GucStringAssignHook assign_hook,
5826                                                    GucShowHook show_hook)
5827 {
5828         struct config_string *var;
5829
5830         var = (struct config_string *)
5831                 init_custom_variable(name, short_desc, long_desc, context, flags,
5832                                                          PGC_STRING, sizeof(struct config_string));
5833         var->variable = valueAddr;
5834         var->boot_val = bootValue;
5835         /* we could probably do without strdup, but keep it like normal case */
5836         if (var->boot_val)
5837                 var->reset_val = guc_strdup(ERROR, var->boot_val);
5838         var->assign_hook = assign_hook;
5839         var->show_hook = show_hook;
5840         define_custom_variable(&var->gen);
5841 }
5842
5843 void
5844 DefineCustomEnumVariable(const char *name,
5845                                                  const char *short_desc,
5846                                                  const char *long_desc,
5847                                                  int *valueAddr,
5848                                                  int bootValue,
5849                                                  const struct config_enum_entry *options,
5850                                                  GucContext context,
5851                                                  int flags,
5852                                                  GucEnumAssignHook assign_hook,
5853                                                  GucShowHook show_hook)
5854 {
5855         struct config_enum *var;
5856
5857         var = (struct config_enum *)
5858                 init_custom_variable(name, short_desc, long_desc, context, flags,
5859                                                          PGC_ENUM, sizeof(struct config_enum));
5860         var->variable = valueAddr;
5861         var->boot_val = bootValue;
5862         var->reset_val = bootValue;
5863         var->options = options;
5864         var->assign_hook = assign_hook;
5865         var->show_hook = show_hook;
5866         define_custom_variable(&var->gen);
5867 }
5868
5869 void
5870 EmitWarningsOnPlaceholders(const char *className)
5871 {
5872         int                     classLen = strlen(className);
5873         int                     i;
5874
5875         for (i = 0; i < num_guc_variables; i++)
5876         {
5877                 struct config_generic *var = guc_variables[i];
5878
5879                 if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
5880                         strncmp(className, var->name, classLen) == 0 &&
5881                         var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
5882                 {
5883                         ereport(WARNING,
5884                                         (errcode(ERRCODE_UNDEFINED_OBJECT),
5885                                          errmsg("unrecognized configuration parameter \"%s\"",
5886                                                         var->name)));
5887                 }
5888         }
5889 }
5890
5891
5892 /*
5893  * SHOW command
5894  */
5895 void
5896 GetPGVariable(const char *name, DestReceiver *dest)
5897 {
5898         if (guc_name_compare(name, "all") == 0)
5899                 ShowAllGUCConfig(dest);
5900         else
5901                 ShowGUCConfigOption(name, dest);
5902 }
5903
5904 TupleDesc
5905 GetPGVariableResultDesc(const char *name)
5906 {
5907         TupleDesc       tupdesc;
5908
5909         if (guc_name_compare(name, "all") == 0)
5910         {
5911                 /* need a tuple descriptor representing three TEXT columns */
5912                 tupdesc = CreateTemplateTupleDesc(3, false);
5913                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5914                                                    TEXTOID, -1, 0);
5915                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5916                                                    TEXTOID, -1, 0);
5917                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5918                                                    TEXTOID, -1, 0);
5919         }
5920         else
5921         {
5922                 const char *varname;
5923
5924                 /* Get the canonical spelling of name */
5925                 (void) GetConfigOptionByName(name, &varname);
5926
5927                 /* need a tuple descriptor representing a single TEXT column */
5928                 tupdesc = CreateTemplateTupleDesc(1, false);
5929                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5930                                                    TEXTOID, -1, 0);
5931         }
5932         return tupdesc;
5933 }
5934
5935
5936 /*
5937  * SHOW command
5938  */
5939 static void
5940 ShowGUCConfigOption(const char *name, DestReceiver *dest)
5941 {
5942         TupOutputState *tstate;
5943         TupleDesc       tupdesc;
5944         const char *varname;
5945         char       *value;
5946
5947         /* Get the value and canonical spelling of name */
5948         value = GetConfigOptionByName(name, &varname);
5949
5950         /* need a tuple descriptor representing a single TEXT column */
5951         tupdesc = CreateTemplateTupleDesc(1, false);
5952         TupleDescInitEntry(tupdesc, (AttrNumber) 1, varname,
5953                                            TEXTOID, -1, 0);
5954
5955         /* prepare for projection of tuples */
5956         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5957
5958         /* Send it */
5959         do_text_output_oneline(tstate, value);
5960
5961         end_tup_output(tstate);
5962 }
5963
5964 /*
5965  * SHOW ALL command
5966  */
5967 static void
5968 ShowAllGUCConfig(DestReceiver *dest)
5969 {
5970         bool            am_superuser = superuser();
5971         int                     i;
5972         TupOutputState *tstate;
5973         TupleDesc       tupdesc;
5974         char       *values[3];
5975
5976         /* need a tuple descriptor representing three TEXT columns */
5977         tupdesc = CreateTemplateTupleDesc(3, false);
5978         TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
5979                                            TEXTOID, -1, 0);
5980         TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
5981                                            TEXTOID, -1, 0);
5982         TupleDescInitEntry(tupdesc, (AttrNumber) 3, "description",
5983                                            TEXTOID, -1, 0);
5984
5985
5986         /* prepare for projection of tuples */
5987         tstate = begin_tup_output_tupdesc(dest, tupdesc);
5988
5989         for (i = 0; i < num_guc_variables; i++)
5990         {
5991                 struct config_generic *conf = guc_variables[i];
5992
5993                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
5994                         ((conf->flags & GUC_SUPERUSER_ONLY) && !am_superuser))
5995                         continue;
5996
5997                 /* assign to the values array */
5998                 values[0] = (char *) conf->name;
5999                 values[1] = _ShowOption(conf, true);
6000                 values[2] = (char *) conf->short_desc;
6001
6002                 /* send it to dest */
6003                 do_tup_output(tstate, values);
6004
6005                 /* clean up */
6006                 if (values[1] != NULL)
6007                         pfree(values[1]);
6008         }
6009
6010         end_tup_output(tstate);
6011 }
6012
6013 /*
6014  * Return GUC variable value by name; optionally return canonical
6015  * form of name.  Return value is palloc'd.
6016  */
6017 char *
6018 GetConfigOptionByName(const char *name, const char **varname)
6019 {
6020         struct config_generic *record;
6021
6022         record = find_option(name, false, ERROR);
6023         if (record == NULL)
6024                 ereport(ERROR,
6025                                 (errcode(ERRCODE_UNDEFINED_OBJECT),
6026                            errmsg("unrecognized configuration parameter \"%s\"", name)));
6027         if ((record->flags & GUC_SUPERUSER_ONLY) && !superuser())
6028                 ereport(ERROR,
6029                                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
6030                                  errmsg("must be superuser to examine \"%s\"", name)));
6031
6032         if (varname)
6033                 *varname = record->name;
6034
6035         return _ShowOption(record, true);
6036 }
6037
6038 /*
6039  * Return GUC variable value by variable number; optionally return canonical
6040  * form of name.  Return value is palloc'd.
6041  */
6042 void
6043 GetConfigOptionByNum(int varnum, const char **values, bool *noshow)
6044 {
6045         char            buffer[256];
6046         struct config_generic *conf;
6047
6048         /* check requested variable number valid */
6049         Assert((varnum >= 0) && (varnum < num_guc_variables));
6050
6051         conf = guc_variables[varnum];
6052
6053         if (noshow)
6054         {
6055                 if ((conf->flags & GUC_NO_SHOW_ALL) ||
6056                         ((conf->flags & GUC_SUPERUSER_ONLY) && !superuser()))
6057                         *noshow = true;
6058                 else
6059                         *noshow = false;
6060         }
6061
6062         /* first get the generic attributes */
6063
6064         /* name */
6065         values[0] = conf->name;
6066
6067         /* setting : use _ShowOption in order to avoid duplicating the logic */
6068         values[1] = _ShowOption(conf, false);
6069
6070         /* unit */
6071         if (conf->vartype == PGC_INT)
6072         {
6073                 static char buf[8];
6074
6075                 switch (conf->flags & (GUC_UNIT_MEMORY | GUC_UNIT_TIME))
6076                 {
6077                         case GUC_UNIT_KB:
6078                                 values[2] = "kB";
6079                                 break;
6080                         case GUC_UNIT_BLOCKS:
6081                                 snprintf(buf, sizeof(buf), "%dkB", BLCKSZ / 1024);
6082                                 values[2] = buf;
6083                                 break;
6084                         case GUC_UNIT_XBLOCKS:
6085                                 snprintf(buf, sizeof(buf), "%dkB", XLOG_BLCKSZ / 1024);
6086                                 values[2] = buf;
6087                                 break;
6088                         case GUC_UNIT_MS:
6089                                 values[2] = "ms";
6090                                 break;
6091                         case GUC_UNIT_S:
6092                                 values[2] = "s";
6093                                 break;
6094                         case GUC_UNIT_MIN:
6095                                 values[2] = "min";
6096                                 break;
6097                         default:
6098                                 values[2] = "";
6099                                 break;
6100                 }
6101         }
6102         else
6103                 values[2] = NULL;
6104
6105         /* group */
6106         values[3] = config_group_names[conf->group];
6107
6108         /* short_desc */
6109         values[4] = conf->short_desc;
6110
6111         /* extra_desc */
6112         values[5] = conf->long_desc;
6113
6114         /* context */
6115         values[6] = GucContext_Names[conf->context];
6116
6117         /* vartype */
6118         values[7] = config_type_names[conf->vartype];
6119
6120         /* source */
6121         values[8] = GucSource_Names[conf->source];
6122
6123         /* now get the type specifc attributes */
6124         switch (conf->vartype)
6125         {
6126                 case PGC_BOOL:
6127                         {
6128                                 struct config_bool *lconf = (struct config_bool *) conf;
6129
6130                                 /* min_val */
6131                                 values[9] = NULL;
6132
6133                                 /* max_val */
6134                                 values[10] = NULL;
6135
6136                                 /* enumvals */
6137                                 values[11] = NULL;
6138
6139                                 /* boot_val */
6140                                 values[12] = pstrdup(lconf->boot_val ? "on" : "off");
6141
6142                                 /* reset_val */
6143                                 values[13] = pstrdup(lconf->reset_val ? "on" : "off");
6144                         }
6145                         break;
6146
6147                 case PGC_INT:
6148                         {
6149                                 struct config_int *lconf = (struct config_int *) conf;
6150
6151                                 /* min_val */
6152                                 snprintf(buffer, sizeof(buffer), "%d", lconf->min);
6153                                 values[9] = pstrdup(buffer);
6154
6155                                 /* max_val */
6156                                 snprintf(buffer, sizeof(buffer), "%d", lconf->max);
6157                                 values[10] = pstrdup(buffer);
6158
6159                                 /* enumvals */
6160                                 values[11] = NULL;
6161
6162                                 /* boot_val */
6163                                 snprintf(buffer, sizeof(buffer), "%d", lconf->boot_val);
6164                                 values[12] = pstrdup(buffer);
6165
6166                                 /* reset_val */
6167                                 snprintf(buffer, sizeof(buffer), "%d", lconf->reset_val);
6168                                 values[13] = pstrdup(buffer);
6169                         }
6170                         break;
6171
6172                 case PGC_REAL:
6173                         {
6174                                 struct config_real *lconf = (struct config_real *) conf;
6175
6176                                 /* min_val */
6177                                 snprintf(buffer, sizeof(buffer), "%g", lconf->min);
6178                                 values[9] = pstrdup(buffer);
6179
6180                                 /* max_val */
6181                                 snprintf(buffer, sizeof(buffer), "%g", lconf->max);
6182                                 values[10] = pstrdup(buffer);
6183
6184                                 /* enumvals */
6185                                 values[11] = NULL;
6186
6187                                 /* boot_val */
6188                                 snprintf(buffer, sizeof(buffer), "%g", lconf->boot_val);
6189                                 values[12] = pstrdup(buffer);
6190
6191                                 /* reset_val */
6192                                 snprintf(buffer, sizeof(buffer), "%g", lconf->reset_val);
6193                                 values[13] = pstrdup(buffer);
6194                         }
6195                         break;
6196
6197                 case PGC_STRING:
6198                         {
6199                                 struct config_string *lconf = (struct config_string *) conf;
6200
6201                                 /* min_val */
6202                                 values[9] = NULL;
6203
6204                                 /* max_val */
6205                                 values[10] = NULL;
6206
6207                                 /* enumvals */
6208                                 values[11] = NULL;
6209
6210                                 /* boot_val */
6211                                 if (lconf->boot_val == NULL)
6212                                         values[12] = NULL;
6213                                 else
6214                                         values[12] = pstrdup(lconf->boot_val);
6215
6216                                 /* reset_val */
6217                                 if (lconf->reset_val == NULL)
6218                                         values[13] = NULL;
6219                                 else
6220                                         values[13] = pstrdup(lconf->reset_val);
6221                         }
6222                         break;
6223
6224                 case PGC_ENUM:
6225                         {
6226                                 struct config_enum *lconf = (struct config_enum *) conf;
6227
6228                                 /* min_val */
6229                                 values[9] = NULL;
6230
6231                                 /* max_val */
6232                                 values[10] = NULL;
6233
6234                                 /* enumvals */
6235                                 /* NOTE! enumvals with double quotes in them are not supported! */
6236                                 values[11] = config_enum_get_options((struct config_enum *) conf,
6237                                                                                                          "{\"", "\"}", "\",\"");
6238
6239                                 /* boot_val */
6240                                 values[12] = pstrdup(config_enum_lookup_by_value(lconf,
6241                                                                                                                                  lconf->boot_val));
6242
6243                                 /* reset_val */
6244                                 values[13] = pstrdup(config_enum_lookup_by_value(lconf,
6245                                                                                                                                  lconf->reset_val));
6246                         }
6247                         break;
6248
6249                 default:
6250                         {
6251                                 /*
6252                                  * should never get here, but in case we do, set 'em to NULL
6253                                  */
6254
6255                                 /* min_val */
6256                                 values[9] = NULL;
6257
6258                                 /* max_val */
6259                                 values[10] = NULL;
6260
6261                                 /* enumvals */
6262                                 values[11] = NULL;
6263
6264                                 /* boot_val */
6265                                 values[12] = NULL;
6266
6267                                 /* reset_val */
6268                                 values[13] = NULL;
6269                         }
6270                         break;
6271         }
6272
6273         /*
6274          * If the setting came from a config file, set the source location.
6275          * For security reasons, we don't show source file/line number for
6276          * non-superusers.
6277          */
6278         if (conf->source == PGC_S_FILE && superuser())
6279         {
6280                 values[14] = conf->sourcefile;
6281                 snprintf(buffer, sizeof(buffer), "%d", conf->sourceline);
6282                 values[15] = pstrdup(buffer);
6283         }
6284         else
6285         {
6286                 values[14] = NULL;
6287                 values[15] = NULL;
6288         }
6289 }
6290
6291 /*
6292  * Return the total number of GUC variables
6293  */
6294 int
6295 GetNumConfigOptions(void)
6296 {
6297         return num_guc_variables;
6298 }
6299
6300 /*
6301  * show_config_by_name - equiv to SHOW X command but implemented as
6302  * a function.
6303  */
6304 Datum
6305 show_config_by_name(PG_FUNCTION_ARGS)
6306 {
6307         char       *varname;
6308         char       *varval;
6309
6310         /* Get the GUC variable name */
6311         varname = TextDatumGetCString(PG_GETARG_DATUM(0));
6312
6313         /* Get the value */
6314         varval = GetConfigOptionByName(varname, NULL);
6315
6316         /* Convert to text */
6317         PG_RETURN_TEXT_P(cstring_to_text(varval));
6318 }
6319
6320 /*
6321  * show_all_settings - equiv to SHOW ALL command but implemented as
6322  * a Table Function.
6323  */
6324 #define NUM_PG_SETTINGS_ATTS    16
6325
6326 Datum
6327 show_all_settings(PG_FUNCTION_ARGS)
6328 {
6329         FuncCallContext *funcctx;
6330         TupleDesc       tupdesc;
6331         int                     call_cntr;
6332         int                     max_calls;
6333         AttInMetadata *attinmeta;
6334         MemoryContext oldcontext;
6335
6336         /* stuff done only on the first call of the function */
6337         if (SRF_IS_FIRSTCALL())
6338         {
6339                 /* create a function context for cross-call persistence */
6340                 funcctx = SRF_FIRSTCALL_INIT();
6341
6342                 /*
6343                  * switch to memory context appropriate for multiple function calls
6344                  */
6345                 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
6346
6347                 /*
6348                  * need a tuple descriptor representing NUM_PG_SETTINGS_ATTS columns
6349                  * of the appropriate types
6350                  */
6351                 tupdesc = CreateTemplateTupleDesc(NUM_PG_SETTINGS_ATTS, false);
6352                 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
6353                                                    TEXTOID, -1, 0);
6354                 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "setting",
6355                                                    TEXTOID, -1, 0);
6356                 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "unit",
6357                                                    TEXTOID, -1, 0);
6358                 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "category",
6359                                                    TEXTOID, -1, 0);
6360                 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "short_desc",
6361                                                    TEXTOID, -1, 0);
6362                 TupleDescInitEntry(tupdesc, (AttrNumber) 6, "extra_desc",
6363                                                    TEXTOID, -1, 0);
6364                 TupleDescInitEntry(tupdesc, (AttrNumber) 7, "context",
6365                                                    TEXTOID, -1, 0);
6366                 TupleDescInitEntry(tupdesc, (AttrNumber) 8, "vartype",
6367                                                    TEXTOID, -1, 0);
6368                 TupleDescInitEntry(tupdesc, (AttrNumber) 9, "source",
6369                                                    TEXTOID, -1, 0);
6370                 TupleDescInitEntry(tupdesc, (AttrNumber) 10, "min_val",
6371                                                    TEXTOID, -1, 0);
6372                 TupleDescInitEntry(tupdesc, (AttrNumber) 11, "max_val",
6373                                                    TEXTOID, -1, 0);
6374                 TupleDescInitEntry(tupdesc, (AttrNumber) 12, "enumvals",
6375                                                    TEXTARRAYOID, -1, 0);
6376                 TupleDescInitEntry(tupdesc, (AttrNumber) 13, "boot_val",
6377                                                    TEXTOID, -1, 0);
6378                 TupleDescInitEntry(tupdesc, (AttrNumber) 14, "reset_val",
6379                                                    TEXTOID, -1, 0);
6380                 TupleDescInitEntry(tupdesc, (AttrNumber) 15, "sourcefile",
6381                                                    TEXTOID, -1, 0);
6382                 TupleDescInitEntry(tupdesc, (AttrNumber) 16, "sourceline",
6383                                                    INT4OID, -1, 0);
6384
6385                 /*
6386                  * Generate attribute metadata needed later to produce tuples from raw
6387                  * C strings
6388                  */
6389                 attinmeta = TupleDescGetAttInMetadata(tupdesc);
6390                 funcctx->attinmeta = attinmeta;
6391
6392                 /* total number of tuples to be returned */
6393                 funcctx->max_calls = GetNumConfigOptions();
6394
6395                 MemoryContextSwitchTo(oldcontext);
6396         }
6397
6398         /* stuff done on every call of the function */
6399         funcctx = SRF_PERCALL_SETUP();
6400
6401         call_cntr = funcctx->call_cntr;
6402         max_calls = funcctx->max_calls;
6403         attinmeta = funcctx->attinmeta;
6404
6405         if (call_cntr < max_calls)      /* do when there is more left to send */
6406         {
6407                 char       *values[NUM_PG_SETTINGS_ATTS];
6408                 bool            noshow;
6409                 HeapTuple       tuple;
6410                 Datum           result;
6411
6412                 /*
6413                  * Get the next visible GUC variable name and value
6414                  */
6415                 do
6416                 {
6417                         GetConfigOptionByNum(call_cntr, (const char **) values, &noshow);
6418                         if (noshow)
6419                         {
6420                                 /* bump the counter and get the next config setting */
6421                                 call_cntr = ++funcctx->call_cntr;
6422
6423                                 /* make sure we haven't gone too far now */
6424                                 if (call_cntr >= max_calls)
6425                                         SRF_RETURN_DONE(funcctx);
6426                         }
6427                 } while (noshow);
6428
6429                 /* build a tuple */
6430                 tuple = BuildTupleFromCStrings(attinmeta, values);
6431
6432                 /* make the tuple into a datum */
6433                 result = HeapTupleGetDatum(tuple);
6434
6435                 SRF_RETURN_NEXT(funcctx, result);
6436         }
6437         else
6438         {
6439                 /* do when there is no more left */
6440                 SRF_RETURN_DONE(funcctx);
6441         }
6442 }
6443
6444 static char *
6445 _ShowOption(struct config_generic * record, bool use_units)
6446 {
6447         char            buffer[256];
6448         const char *val;
6449
6450         switch (record->vartype)
6451         {
6452                 case PGC_BOOL:
6453                         {
6454                                 struct config_bool *conf = (struct config_bool *) record;
6455
6456                                 if (conf->show_hook)
6457                                         val = (*conf->show_hook) ();
6458                                 else
6459                                         val = *conf->variable ? "on" : "off";
6460                         }
6461                         break;
6462
6463                 case PGC_INT:
6464                         {
6465                                 struct config_int *conf = (struct config_int *) record;
6466
6467                                 if (conf->show_hook)
6468                                         val = (*conf->show_hook) ();
6469                                 else
6470                                 {
6471                                         /*
6472                                          * Use int64 arithmetic to avoid overflows in units
6473                                          * conversion.  If INT64_IS_BUSTED we might overflow
6474                                          * anyway and print bogus answers, but there are few
6475                                          * enough such machines that it doesn't seem worth
6476                                          * trying harder.
6477                                          */
6478                                         int64           result = *conf->variable;
6479                                         const char *unit;
6480
6481                                         if (use_units && result > 0 &&
6482                                                 (record->flags & GUC_UNIT_MEMORY))
6483                                         {
6484                                                 switch (record->flags & GUC_UNIT_MEMORY)
6485                                                 {
6486                                                         case GUC_UNIT_BLOCKS:
6487                                                                 result *= BLCKSZ / 1024;
6488                                                                 break;
6489                                                         case GUC_UNIT_XBLOCKS:
6490                                                                 result *= XLOG_BLCKSZ / 1024;
6491                                                                 break;
6492                                                 }
6493
6494                                                 if (result % KB_PER_GB == 0)
6495                                                 {
6496                                                         result /= KB_PER_GB;
6497                                                         unit = "GB";
6498                                                 }
6499                                                 else if (result % KB_PER_MB == 0)
6500                                                 {
6501                                                         result /= KB_PER_MB;
6502                                                         unit = "MB";
6503                                                 }
6504                                                 else
6505                                                 {
6506                                                         unit = "kB";
6507                                                 }
6508                                         }
6509                                         else if (use_units && result > 0 &&
6510                                                          (record->flags & GUC_UNIT_TIME))
6511                                         {
6512                                                 switch (record->flags & GUC_UNIT_TIME)
6513                                                 {
6514                                                         case GUC_UNIT_S:
6515                                                                 result *= MS_PER_S;
6516                                                                 break;
6517                                                         case GUC_UNIT_MIN:
6518                                                                 result *= MS_PER_MIN;
6519                                                                 break;
6520                                                 }
6521
6522                                                 if (result % MS_PER_D == 0)
6523                                                 {
6524                                                         result /= MS_PER_D;
6525                                                         unit = "d";
6526                                                 }
6527                                                 else if (result % MS_PER_H == 0)
6528                                                 {
6529                                                         result /= MS_PER_H;
6530                                                         unit = "h";
6531                                                 }
6532                                                 else if (result % MS_PER_MIN == 0)
6533                                                 {
6534                                                         result /= MS_PER_MIN;
6535                                                         unit = "min";
6536                                                 }
6537                                                 else if (result % MS_PER_S == 0)
6538                                                 {
6539                                                         result /= MS_PER_S;
6540                                                         unit = "s";
6541                                                 }
6542                                                 else
6543                                                 {
6544                                                         unit = "ms";
6545                                                 }
6546                                         }
6547                                         else
6548                                                 unit = "";
6549
6550                                         snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
6551                                                          result, unit);
6552                                         val = buffer;
6553                                 }
6554                         }
6555                         break;
6556
6557                 case PGC_REAL:
6558                         {
6559                                 struct config_real *conf = (struct config_real *) record;
6560
6561                                 if (conf->show_hook)
6562                                         val = (*conf->show_hook) ();
6563                                 else
6564                                 {
6565                                         snprintf(buffer, sizeof(buffer), "%g",
6566                                                          *conf->variable);
6567                                         val = buffer;
6568                                 }
6569                         }
6570                         break;
6571
6572                 case PGC_STRING:
6573                         {
6574                                 struct config_string *conf = (struct config_string *) record;
6575
6576                                 if (conf->show_hook)
6577                                         val = (*conf->show_hook) ();
6578                                 else if (*conf->variable && **conf->variable)
6579                                         val = *conf->variable;
6580                                 else
6581                                         val = "";
6582                         }
6583                         break;
6584
6585                 case PGC_ENUM:
6586                         {
6587                                 struct config_enum *conf = (struct config_enum *) record;
6588
6589                                 if(conf->show_hook)
6590                                         val = (*conf->show_hook) ();
6591                                 else
6592                                         val = config_enum_lookup_by_value(conf, *conf->variable);
6593                         }
6594                         break;
6595
6596                 default:
6597                         /* just to keep compiler quiet */
6598                         val = "???";
6599                         break;
6600         }
6601
6602         return pstrdup(val);
6603 }
6604
6605
6606 /*
6607  * Attempt (badly) to detect if a proposed new GUC setting is the same
6608  * as the current value.
6609  *
6610  * XXX this does not really work because it doesn't account for the
6611  * effects of canonicalization of string values by assign_hooks.
6612  */
6613 static bool
6614 is_newvalue_equal(struct config_generic * record, const char *newvalue)
6615 {
6616         /* newvalue == NULL isn't supported */
6617         Assert(newvalue != NULL);
6618
6619         switch (record->vartype)
6620         {
6621                 case PGC_BOOL:
6622                         {
6623                                 struct config_bool *conf = (struct config_bool *) record;
6624                                 bool            newval;
6625
6626                                 return parse_bool(newvalue, &newval)
6627                                         && *conf->variable == newval;
6628                         }
6629                 case PGC_INT:
6630                         {
6631                                 struct config_int *conf = (struct config_int *) record;
6632                                 int                     newval;
6633
6634                                 return parse_int(newvalue, &newval, record->flags, NULL)
6635                                         && *conf->variable == newval;
6636                         }
6637                 case PGC_REAL:
6638                         {
6639                                 struct config_real *conf = (struct config_real *) record;
6640                                 double          newval;
6641
6642                                 return parse_real(newvalue, &newval)
6643                                         && *conf->variable == newval;
6644                         }
6645                 case PGC_STRING:
6646                         {
6647                                 struct config_string *conf = (struct config_string *) record;
6648
6649                                 return *conf->variable != NULL &&
6650                                         strcmp(*conf->variable, newvalue) == 0;
6651                         }
6652
6653                 case PGC_ENUM:
6654                         {
6655                                 struct config_enum *conf = (struct config_enum *) record;
6656                                 int                     newval;
6657
6658                                 return config_enum_lookup_by_name(conf, newvalue, &newval) &&
6659                                         *conf->variable == newval;
6660                         }
6661         }
6662
6663         return false;
6664 }
6665
6666
6667 #ifdef EXEC_BACKEND
6668
6669 /*
6670  *      These routines dump out all non-default GUC options into a binary
6671  *      file that is read by all exec'ed backends.  The format is:
6672  *
6673  *              variable name, string, null terminated
6674  *              variable value, string, null terminated
6675  *              variable source, integer
6676  */
6677 static void
6678 write_one_nondefault_variable(FILE *fp, struct config_generic *gconf)
6679 {
6680         if (gconf->source == PGC_S_DEFAULT)
6681                 return;
6682
6683         fprintf(fp, "%s", gconf->name);
6684         fputc(0, fp);
6685
6686         switch (gconf->vartype)
6687         {
6688                 case PGC_BOOL:
6689                 {
6690                         struct config_bool *conf = (struct config_bool *) gconf;
6691
6692                         if (*conf->variable)
6693                                 fprintf(fp, "true");
6694                         else
6695                                 fprintf(fp, "false");
6696                 }
6697                 break;
6698
6699                 case PGC_INT:
6700                 {
6701                         struct config_int *conf = (struct config_int *) gconf;
6702
6703                         fprintf(fp, "%d", *conf->variable);
6704                 }
6705                 break;
6706
6707                 case PGC_REAL:
6708                 {
6709                         struct config_real *conf = (struct config_real *) gconf;
6710
6711                         /* Could lose precision here? */
6712                         fprintf(fp, "%f", *conf->variable);
6713                 }
6714                 break;
6715
6716                 case PGC_STRING:
6717                 {
6718                         struct config_string *conf = (struct config_string *) gconf;
6719
6720                         fprintf(fp, "%s", *conf->variable);
6721                 }
6722                 break;
6723
6724                 case PGC_ENUM:
6725                 {
6726                         struct config_enum *conf = (struct config_enum *) gconf;
6727
6728                         fprintf(fp, "%s",
6729                                         config_enum_lookup_by_value(conf, *conf->variable));
6730                 }
6731                 break;
6732         }
6733
6734         fputc(0, fp);
6735
6736         fwrite(&gconf->source, sizeof(gconf->source), 1, fp);
6737 }
6738
6739 void
6740 write_nondefault_variables(GucContext context)
6741 {
6742         int                     elevel;
6743         FILE       *fp;
6744         struct config_generic *cvc_conf;
6745         int                     i;
6746
6747         Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
6748
6749         elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
6750
6751         /*
6752          * Open file
6753          */
6754         fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
6755         if (!fp)
6756         {
6757                 ereport(elevel,
6758                                 (errcode_for_file_access(),
6759                                  errmsg("could not write to file \"%s\": %m",
6760                                                 CONFIG_EXEC_PARAMS_NEW)));
6761                 return;
6762         }
6763
6764         /*
6765          * custom_variable_classes must be written out first; otherwise we might
6766          * reject custom variable values while reading the file.
6767          */
6768         cvc_conf = find_option("custom_variable_classes", false, ERROR);
6769         if (cvc_conf)
6770                 write_one_nondefault_variable(fp, cvc_conf);
6771
6772         for (i = 0; i < num_guc_variables; i++)
6773         {
6774                 struct config_generic *gconf = guc_variables[i];
6775
6776                 if (gconf != cvc_conf)
6777                         write_one_nondefault_variable(fp, gconf);
6778         }
6779
6780         if (FreeFile(fp))
6781         {
6782                 ereport(elevel,
6783                                 (errcode_for_file_access(),
6784                                  errmsg("could not write to file \"%s\": %m",
6785                                                 CONFIG_EXEC_PARAMS_NEW)));
6786                 return;
6787         }
6788
6789         /*
6790          * Put new file in place.  This could delay on Win32, but we don't hold
6791          * any exclusive locks.
6792          */
6793         rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
6794 }
6795
6796
6797 /*
6798  *      Read string, including null byte from file
6799  *
6800  *      Return NULL on EOF and nothing read
6801  */
6802 static char *
6803 read_string_with_null(FILE *fp)
6804 {
6805         int                     i = 0,
6806                                 ch,
6807                                 maxlen = 256;
6808         char       *str = NULL;
6809
6810         do
6811         {
6812                 if ((ch = fgetc(fp)) == EOF)
6813                 {
6814                         if (i == 0)
6815                                 return NULL;
6816                         else
6817                                 elog(FATAL, "invalid format of exec config params file");
6818                 }
6819                 if (i == 0)
6820                         str = guc_malloc(FATAL, maxlen);
6821                 else if (i == maxlen)
6822                         str = guc_realloc(FATAL, str, maxlen *= 2);
6823                 str[i++] = ch;
6824         } while (ch != 0);
6825
6826         return str;
6827 }
6828
6829
6830 /*
6831  *      This routine loads a previous postmaster dump of its non-default
6832  *      settings.
6833  */
6834 void
6835 read_nondefault_variables(void)
6836 {
6837         FILE       *fp;
6838         char       *varname,
6839                            *varvalue;
6840         int                     varsource;
6841
6842         /*
6843          * Open file
6844          */
6845         fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
6846         if (!fp)
6847         {
6848                 /* File not found is fine */
6849                 if (errno != ENOENT)
6850                         ereport(FATAL,
6851                                         (errcode_for_file_access(),
6852                                          errmsg("could not read from file \"%s\": %m",
6853                                                         CONFIG_EXEC_PARAMS)));
6854                 return;
6855         }
6856
6857         for (;;)
6858         {
6859                 struct config_generic *record;
6860
6861                 if ((varname = read_string_with_null(fp)) == NULL)
6862                         break;
6863
6864                 if ((record = find_option(varname, true, FATAL)) == NULL)
6865                         elog(FATAL, "failed to locate variable %s in exec config params file", varname);
6866                 if ((varvalue = read_string_with_null(fp)) == NULL)
6867                         elog(FATAL, "invalid format of exec config params file");
6868                 if (fread(&varsource, sizeof(varsource), 1, fp) == 0)
6869                         elog(FATAL, "invalid format of exec config params file");
6870
6871                 (void) set_config_option(varname, varvalue, record->context,
6872                                                                  varsource, GUC_ACTION_SET, true);
6873                 free(varname);
6874                 free(varvalue);
6875         }
6876
6877         FreeFile(fp);
6878 }
6879 #endif   /* EXEC_BACKEND */
6880
6881
6882 /*
6883  * A little "long argument" simulation, although not quite GNU
6884  * compliant. Takes a string of the form "some-option=some value" and
6885  * returns name = "some_option" and value = "some value" in malloc'ed
6886  * storage. Note that '-' is converted to '_' in the option name. If
6887  * there is no '=' in the input string then value will be NULL.
6888  */
6889 void
6890 ParseLongOption(const char *string, char **name, char **value)
6891 {
6892         size_t          equal_pos;
6893         char       *cp;
6894
6895         AssertArg(string);
6896         AssertArg(name);
6897         AssertArg(value);
6898
6899         equal_pos = strcspn(string, "=");
6900
6901         if (string[equal_pos] == '=')
6902         {
6903                 *name = guc_malloc(FATAL, equal_pos + 1);
6904                 strlcpy(*name, string, equal_pos + 1);
6905
6906                 *value = guc_strdup(FATAL, &string[equal_pos + 1]);
6907         }
6908         else
6909         {
6910                 /* no equal sign in string */
6911                 *name = guc_strdup(FATAL, string);
6912                 *value = NULL;
6913         }
6914
6915         for (cp = *name; *cp; cp++)
6916                 if (*cp == '-')
6917                         *cp = '_';
6918 }
6919
6920
6921 /*
6922  * Handle options fetched from pg_database.datconfig, pg_authid.rolconfig,
6923  * pg_proc.proconfig, etc.      Caller must specify proper context/source/action.
6924  *
6925  * The array parameter must be an array of TEXT (it must not be NULL).
6926  */
6927 void
6928 ProcessGUCArray(ArrayType *array,
6929                                 GucContext context, GucSource source, GucAction action)
6930 {
6931         int                     i;
6932
6933         Assert(array != NULL);
6934         Assert(ARR_ELEMTYPE(array) == TEXTOID);
6935         Assert(ARR_NDIM(array) == 1);
6936         Assert(ARR_LBOUND(array)[0] == 1);
6937
6938         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
6939         {
6940                 Datum           d;
6941                 bool            isnull;
6942                 char       *s;
6943                 char       *name;
6944                 char       *value;
6945
6946                 d = array_ref(array, 1, &i,
6947                                           -1 /* varlenarray */ ,
6948                                           -1 /* TEXT's typlen */ ,
6949                                           false /* TEXT's typbyval */ ,
6950                                           'i' /* TEXT's typalign */ ,
6951                                           &isnull);
6952
6953                 if (isnull)
6954                         continue;
6955
6956                 s = TextDatumGetCString(d);
6957
6958                 ParseLongOption(s, &name, &value);
6959                 if (!value)
6960                 {
6961                         ereport(WARNING,
6962                                         (errcode(ERRCODE_SYNTAX_ERROR),
6963                                          errmsg("could not parse setting for parameter \"%s\"",
6964                                                         name)));
6965                         free(name);
6966                         continue;
6967                 }
6968
6969                 (void) set_config_option(name, value, context, source, action, true);
6970
6971                 free(name);
6972                 if (value)
6973                         free(value);
6974         }
6975 }
6976
6977
6978 /*
6979  * Add an entry to an option array.  The array parameter may be NULL
6980  * to indicate the current table entry is NULL.
6981  */
6982 ArrayType *
6983 GUCArrayAdd(ArrayType *array, const char *name, const char *value)
6984 {
6985         const char *varname;
6986         Datum           datum;
6987         char       *newval;
6988         ArrayType  *a;
6989
6990         Assert(name);
6991         Assert(value);
6992
6993         /* test if the option is valid */
6994         set_config_option(name, value,
6995                                           superuser() ? PGC_SUSET : PGC_USERSET,
6996                                           PGC_S_TEST, GUC_ACTION_SET, false);
6997
6998         /* convert name to canonical spelling, so we can use plain strcmp */
6999         (void) GetConfigOptionByName(name, &varname);
7000         name = varname;
7001
7002         newval = palloc(strlen(name) + 1 + strlen(value) + 1);
7003         sprintf(newval, "%s=%s", name, value);
7004         datum = CStringGetTextDatum(newval);
7005
7006         if (array)
7007         {
7008                 int                     index;
7009                 bool            isnull;
7010                 int                     i;
7011
7012                 Assert(ARR_ELEMTYPE(array) == TEXTOID);
7013                 Assert(ARR_NDIM(array) == 1);
7014                 Assert(ARR_LBOUND(array)[0] == 1);
7015
7016                 index = ARR_DIMS(array)[0] + 1; /* add after end */
7017
7018                 for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7019                 {
7020                         Datum           d;
7021                         char       *current;
7022
7023                         d = array_ref(array, 1, &i,
7024                                                   -1 /* varlenarray */ ,
7025                                                   -1 /* TEXT's typlen */ ,
7026                                                   false /* TEXT's typbyval */ ,
7027                                                   'i' /* TEXT's typalign */ ,
7028                                                   &isnull);
7029                         if (isnull)
7030                                 continue;
7031                         current = TextDatumGetCString(d);
7032                         if (strncmp(current, newval, strlen(name) + 1) == 0)
7033                         {
7034                                 index = i;
7035                                 break;
7036                         }
7037                 }
7038
7039                 a = array_set(array, 1, &index,
7040                                           datum,
7041                                           false,
7042                                           -1 /* varlena array */ ,
7043                                           -1 /* TEXT's typlen */ ,
7044                                           false /* TEXT's typbyval */ ,
7045                                           'i' /* TEXT's typalign */ );
7046         }
7047         else
7048                 a = construct_array(&datum, 1,
7049                                                         TEXTOID,
7050                                                         -1, false, 'i');
7051
7052         return a;
7053 }
7054
7055
7056 /*
7057  * Delete an entry from an option array.  The array parameter may be NULL
7058  * to indicate the current table entry is NULL.  Also, if the return value
7059  * is NULL then a null should be stored.
7060  */
7061 ArrayType *
7062 GUCArrayDelete(ArrayType *array, const char *name)
7063 {
7064         const char *varname;
7065         ArrayType  *newarray;
7066         int                     i;
7067         int                     index;
7068
7069         Assert(name);
7070
7071         /* test if the option is valid */
7072         set_config_option(name, NULL,
7073                                           superuser() ? PGC_SUSET : PGC_USERSET,
7074                                           PGC_S_TEST, GUC_ACTION_SET, false);
7075
7076         /* convert name to canonical spelling, so we can use plain strcmp */
7077         (void) GetConfigOptionByName(name, &varname);
7078         name = varname;
7079
7080         /* if array is currently null, then surely nothing to delete */
7081         if (!array)
7082                 return NULL;
7083
7084         newarray = NULL;
7085         index = 1;
7086
7087         for (i = 1; i <= ARR_DIMS(array)[0]; i++)
7088         {
7089                 Datum           d;
7090                 char       *val;
7091                 bool            isnull;
7092
7093                 d = array_ref(array, 1, &i,
7094                                           -1 /* varlenarray */ ,
7095                                           -1 /* TEXT's typlen */ ,
7096                                           false /* TEXT's typbyval */ ,
7097                                           'i' /* TEXT's typalign */ ,
7098                                           &isnull);
7099                 if (isnull)
7100                         continue;
7101                 val = TextDatumGetCString(d);
7102
7103                 /* ignore entry if it's what we want to delete */
7104                 if (strncmp(val, name, strlen(name)) == 0
7105                         && val[strlen(name)] == '=')
7106                         continue;
7107
7108                 /* else add it to the output array */
7109                 if (newarray)
7110                 {
7111                         newarray = array_set(newarray, 1, &index,
7112                                                                  d,
7113                                                                  false,
7114                                                                  -1 /* varlenarray */ ,
7115                                                                  -1 /* TEXT's typlen */ ,
7116                                                                  false /* TEXT's typbyval */ ,
7117                                                                  'i' /* TEXT's typalign */ );
7118                 }
7119                 else
7120                         newarray = construct_array(&d, 1,
7121                                                                            TEXTOID,
7122                                                                            -1, false, 'i');
7123
7124                 index++;
7125         }
7126
7127         return newarray;
7128 }
7129
7130
7131 /*
7132  * assign_hook and show_hook subroutines
7133  */
7134
7135 static const char *
7136 assign_log_destination(const char *value, bool doit, GucSource source)
7137 {
7138         char       *rawstring;
7139         List       *elemlist;
7140         ListCell   *l;
7141         int                     newlogdest = 0;
7142
7143         /* Need a modifiable copy of string */
7144         rawstring = pstrdup(value);
7145
7146         /* Parse string into list of identifiers */
7147         if (!SplitIdentifierString(rawstring, ',', &elemlist))
7148         {
7149                 /* syntax error in list */
7150                 pfree(rawstring);
7151                 list_free(elemlist);
7152                 ereport(GUC_complaint_elevel(source),
7153                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7154                         errmsg("invalid list syntax for parameter \"log_destination\"")));
7155                 return NULL;
7156         }
7157
7158         foreach(l, elemlist)
7159         {
7160                 char       *tok = (char *) lfirst(l);
7161
7162                 if (pg_strcasecmp(tok, "stderr") == 0)
7163                         newlogdest |= LOG_DESTINATION_STDERR;
7164                 else if (pg_strcasecmp(tok, "csvlog") == 0)
7165                         newlogdest |= LOG_DESTINATION_CSVLOG;
7166 #ifdef HAVE_SYSLOG
7167                 else if (pg_strcasecmp(tok, "syslog") == 0)
7168                         newlogdest |= LOG_DESTINATION_SYSLOG;
7169 #endif
7170 #ifdef WIN32
7171                 else if (pg_strcasecmp(tok, "eventlog") == 0)
7172                         newlogdest |= LOG_DESTINATION_EVENTLOG;
7173 #endif
7174                 else
7175                 {
7176                         ereport(GUC_complaint_elevel(source),
7177                                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7178                                   errmsg("unrecognized \"log_destination\" key word: \"%s\"",
7179                                                  tok)));
7180                         pfree(rawstring);
7181                         list_free(elemlist);
7182                         return NULL;
7183                 }
7184         }
7185
7186         if (doit)
7187                 Log_destination = newlogdest;
7188
7189         pfree(rawstring);
7190         list_free(elemlist);
7191
7192         return value;
7193 }
7194
7195 #ifdef HAVE_SYSLOG
7196
7197 static bool
7198 assign_syslog_facility(int newval, bool doit, GucSource source)
7199 {
7200         if (doit)
7201                 set_syslog_parameters(syslog_ident_str ? syslog_ident_str : "postgres",
7202                                                           newval);
7203
7204         return true;
7205 }
7206
7207 static const char *
7208 assign_syslog_ident(const char *ident, bool doit, GucSource source)
7209 {
7210         if (doit)
7211                 set_syslog_parameters(ident, syslog_facility);
7212
7213         return ident;
7214 }
7215 #endif   /* HAVE_SYSLOG */
7216
7217
7218 static bool
7219 assign_session_replication_role(int newval, bool doit, GucSource source)
7220 {
7221         /*
7222          * Must flush the plan cache when changing replication role; but don't
7223          * flush unnecessarily.
7224          */
7225         if (doit && SessionReplicationRole != newval)
7226         {
7227                 ResetPlanCache();
7228         }
7229
7230         return true;
7231 }
7232
7233 static const char *
7234 show_num_temp_buffers(void)
7235 {
7236         /*
7237          * We show the GUC var until local buffers have been initialized, and
7238          * NLocBuffer afterwards.
7239          */
7240         static char nbuf[32];
7241
7242         sprintf(nbuf, "%d", NLocBuffer ? NLocBuffer : num_temp_buffers);
7243         return nbuf;
7244 }
7245
7246 static bool
7247 assign_phony_autocommit(bool newval, bool doit, GucSource source)
7248 {
7249         if (!newval)
7250         {
7251                 ereport(GUC_complaint_elevel(source),
7252                                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
7253                                  errmsg("SET AUTOCOMMIT TO OFF is no longer supported")));
7254                 return false;
7255         }
7256         return true;
7257 }
7258
7259 static const char *
7260 assign_custom_variable_classes(const char *newval, bool doit, GucSource source)
7261 {
7262         /*
7263          * Check syntax. newval must be a comma separated list of identifiers.
7264          * Whitespace is allowed but removed from the result.
7265          */
7266         bool            hasSpaceAfterToken = false;
7267         const char *cp = newval;
7268         int                     symLen = 0;
7269         char            c;
7270         StringInfoData buf;
7271
7272         initStringInfo(&buf);
7273         while ((c = *cp++) != '\0')
7274         {
7275                 if (isspace((unsigned char) c))
7276                 {
7277                         if (symLen > 0)
7278                                 hasSpaceAfterToken = true;
7279                         continue;
7280                 }
7281
7282                 if (c == ',')
7283                 {
7284                         if (symLen > 0)         /* terminate identifier */
7285                         {
7286                                 appendStringInfoChar(&buf, ',');
7287                                 symLen = 0;
7288                         }
7289                         hasSpaceAfterToken = false;
7290                         continue;
7291                 }
7292
7293                 if (hasSpaceAfterToken || !(isalnum((unsigned char) c) || c == '_'))
7294                 {
7295                         /*
7296                          * Syntax error due to token following space after token or
7297                          * non-identifier character
7298                          */
7299                         pfree(buf.data);
7300                         return NULL;
7301                 }
7302                 appendStringInfoChar(&buf, c);
7303                 symLen++;
7304         }
7305
7306         /* Remove stray ',' at end */
7307         if (symLen == 0 && buf.len > 0)
7308                 buf.data[--buf.len] = '\0';
7309
7310         /* GUC wants the result malloc'd */
7311         newval = guc_strdup(LOG, buf.data);
7312
7313         pfree(buf.data);
7314         return newval;
7315 }
7316
7317 static bool
7318 assign_debug_assertions(bool newval, bool doit, GucSource source)
7319 {
7320 #ifndef USE_ASSERT_CHECKING
7321         if (newval)
7322         {
7323                 ereport(GUC_complaint_elevel(source),
7324                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7325                            errmsg("assertion checking is not supported by this build")));
7326                 return false;
7327         }
7328 #endif
7329         return true;
7330 }
7331
7332 static bool
7333 assign_ssl(bool newval, bool doit, GucSource source)
7334 {
7335 #ifndef USE_SSL
7336         if (newval)
7337         {
7338                 ereport(GUC_complaint_elevel(source),
7339                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7340                                  errmsg("SSL is not supported by this build")));
7341                 return false;
7342         }
7343 #endif
7344         return true;
7345 }
7346
7347 static bool
7348 assign_stage_log_stats(bool newval, bool doit, GucSource source)
7349 {
7350         if (newval && log_statement_stats)
7351         {
7352                 ereport(GUC_complaint_elevel(source),
7353                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7354                                  errmsg("cannot enable parameter when \"log_statement_stats\" is true")));
7355                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7356                 if (source != PGC_S_OVERRIDE)
7357                         return false;
7358         }
7359         return true;
7360 }
7361
7362 static bool
7363 assign_log_stats(bool newval, bool doit, GucSource source)
7364 {
7365         if (newval &&
7366                 (log_parser_stats || log_planner_stats || log_executor_stats))
7367         {
7368                 ereport(GUC_complaint_elevel(source),
7369                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7370                                  errmsg("cannot enable \"log_statement_stats\" when "
7371                                                 "\"log_parser_stats\", \"log_planner_stats\", "
7372                                                 "or \"log_executor_stats\" is true")));
7373                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7374                 if (source != PGC_S_OVERRIDE)
7375                         return false;
7376         }
7377         return true;
7378 }
7379
7380 static bool
7381 assign_transaction_read_only(bool newval, bool doit, GucSource source)
7382 {
7383         /* Can't go to r/w mode inside a r/o transaction */
7384         if (newval == false && XactReadOnly && IsSubTransaction())
7385         {
7386                 ereport(GUC_complaint_elevel(source),
7387                                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
7388                                  errmsg("cannot set transaction read-write mode inside a read-only transaction")));
7389                 /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
7390                 if (source != PGC_S_OVERRIDE)
7391                         return false;
7392         }
7393         return true;
7394 }
7395
7396 static const char *
7397 assign_canonical_path(const char *newval, bool doit, GucSource source)
7398 {
7399         if (doit)
7400         {
7401                 char       *canon_val = guc_strdup(ERROR, newval);
7402
7403                 canonicalize_path(canon_val);
7404                 return canon_val;
7405         }
7406         else
7407                 return newval;
7408 }
7409
7410 static const char *
7411 assign_timezone_abbreviations(const char *newval, bool doit, GucSource source)
7412 {
7413         /*
7414          * The powerup value shown above for timezone_abbreviations is "UNKNOWN".
7415          * When we see this we just do nothing.  If this value isn't overridden
7416          * from the config file then pg_timezone_abbrev_initialize() will
7417          * eventually replace it with "Default".  This hack has two purposes: to
7418          * avoid wasting cycles loading values that might soon be overridden from
7419          * the config file, and to avoid trying to read the timezone abbrev files
7420          * during InitializeGUCOptions().  The latter doesn't work in an
7421          * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet and so
7422          * we can't locate PGSHAREDIR.  (Essentially the same hack is used to
7423          * delay initializing TimeZone ... if we have any more, we should try to
7424          * clean up and centralize this mechanism ...)
7425          */
7426         if (strcmp(newval, "UNKNOWN") == 0)
7427         {
7428                 return newval;
7429         }
7430
7431         /* Loading abbrev file is expensive, so only do it when value changes */
7432         if (timezone_abbreviations_string == NULL ||
7433                 strcmp(timezone_abbreviations_string, newval) != 0)
7434         {
7435                 int                     elevel;
7436
7437                 /*
7438                  * If reading config file, only the postmaster should bleat loudly
7439                  * about problems.      Otherwise, it's just this one process doing it,
7440                  * and we use WARNING message level.
7441                  */
7442                 if (source == PGC_S_FILE)
7443                         elevel = IsUnderPostmaster ? DEBUG3 : LOG;
7444                 else
7445                         elevel = WARNING;
7446                 if (!load_tzoffsets(newval, doit, elevel))
7447                         return NULL;
7448         }
7449         return newval;
7450 }
7451
7452 /*
7453  * pg_timezone_abbrev_initialize --- set default value if not done already
7454  *
7455  * This is called after initial loading of postgresql.conf.  If no
7456  * timezone_abbreviations setting was found therein, select default.
7457  */
7458 void
7459 pg_timezone_abbrev_initialize(void)
7460 {
7461         if (strcmp(timezone_abbreviations_string, "UNKNOWN") == 0)
7462         {
7463                 SetConfigOption("timezone_abbreviations", "Default",
7464                                                 PGC_POSTMASTER, PGC_S_ARGV);
7465         }
7466 }
7467
7468 static const char *
7469 show_archive_command(void)
7470 {
7471         if (XLogArchiveMode)
7472                 return XLogArchiveCommand;
7473         else
7474                 return "(disabled)";
7475 }
7476
7477 static bool
7478 assign_tcp_keepalives_idle(int newval, bool doit, GucSource source)
7479 {
7480         if (doit)
7481                 return (pq_setkeepalivesidle(newval, MyProcPort) == STATUS_OK);
7482
7483         return true;
7484 }
7485
7486 static const char *
7487 show_tcp_keepalives_idle(void)
7488 {
7489         static char nbuf[16];
7490
7491         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
7492         return nbuf;
7493 }
7494
7495 static bool
7496 assign_tcp_keepalives_interval(int newval, bool doit, GucSource source)
7497 {
7498         if (doit)
7499                 return (pq_setkeepalivesinterval(newval, MyProcPort) == STATUS_OK);
7500
7501         return true;
7502 }
7503
7504 static const char *
7505 show_tcp_keepalives_interval(void)
7506 {
7507         static char nbuf[16];
7508
7509         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
7510         return nbuf;
7511 }
7512
7513 static bool
7514 assign_tcp_keepalives_count(int newval, bool doit, GucSource source)
7515 {
7516         if (doit)
7517                 return (pq_setkeepalivescount(newval, MyProcPort) == STATUS_OK);
7518
7519         return true;
7520 }
7521
7522 static const char *
7523 show_tcp_keepalives_count(void)
7524 {
7525         static char nbuf[16];
7526
7527         snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
7528         return nbuf;
7529 }
7530
7531 static bool
7532 assign_maxconnections(int newval, bool doit, GucSource source)
7533 {
7534         if (newval + autovacuum_max_workers > INT_MAX / 4)
7535                 return false;
7536
7537         if (doit)
7538                 MaxBackends = newval + autovacuum_max_workers;
7539
7540         return true;
7541 }
7542
7543 static bool
7544 assign_autovacuum_max_workers(int newval, bool doit, GucSource source)
7545 {
7546         if (newval + MaxConnections > INT_MAX / 4)
7547                 return false;
7548
7549         if (doit)
7550                 MaxBackends = newval + MaxConnections;
7551
7552         return true;
7553 }
7554
7555 static bool
7556 assign_effective_io_concurrency(int newval, bool doit, GucSource source)
7557 {
7558 #ifdef USE_PREFETCH
7559         double          new_prefetch_pages = 0.0;
7560         int                     i;
7561
7562         /*----------
7563          * The user-visible GUC parameter is the number of drives (spindles),
7564          * which we need to translate to a number-of-pages-to-prefetch target.
7565          *
7566          * The expected number of prefetch pages needed to keep N drives busy is:
7567          *
7568          * drives |   I/O requests
7569          * -------+----------------
7570          *      1 |   1
7571          *      2 |   2/1 + 2/2 = 3
7572          *      3 |   3/1 + 3/2 + 3/3 = 5 1/2
7573          *      4 |   4/1 + 4/2 + 4/3 + 4/4 = 8 1/3
7574          *      n |   n * H(n)
7575          *
7576          * This is called the "coupon collector problem" and H(n) is called the
7577          * harmonic series.  This could be approximated by n * ln(n), but for
7578          * reasonable numbers of drives we might as well just compute the series.
7579          *
7580          * Alternatively we could set the target to the number of pages necessary
7581          * so that the expected number of active spindles is some arbitrary
7582          * percentage of the total.  This sounds the same but is actually slightly
7583          * different.  The result ends up being ln(1-P)/ln((n-1)/n) where P is
7584          * that desired fraction.
7585          *
7586          * Experimental results show that both of these formulas aren't aggressive
7587          * enough, but we don't really have any better proposals.
7588          *
7589          * Note that if newval = 0 (disabled), we must set target = 0.
7590          *----------
7591          */
7592
7593         for (i = 1; i <= newval; i++)
7594                 new_prefetch_pages += (double) newval / (double) i;
7595
7596         /* This range check shouldn't fail, but let's be paranoid */
7597         if (new_prefetch_pages >= 0.0 && new_prefetch_pages < (double) INT_MAX)
7598         {
7599                 if (doit)
7600                         target_prefetch_pages = (int) rint(new_prefetch_pages);
7601                 return true;
7602         }
7603         else
7604                 return false;
7605 #else
7606         return true;
7607 #endif /* USE_PREFETCH */
7608 }
7609
7610 static const char *
7611 assign_pgstat_temp_directory(const char *newval, bool doit, GucSource source)
7612 {
7613         if (doit)
7614         {
7615                 if (pgstat_stat_tmpname)
7616                         free(pgstat_stat_tmpname);
7617                 if (pgstat_stat_filename)
7618                         free(pgstat_stat_filename);
7619
7620                 pgstat_stat_tmpname = guc_malloc(FATAL, strlen(newval) + 12);  /* /pgstat.tmp */
7621                 pgstat_stat_filename = guc_malloc(FATAL, strlen(newval) + 13); /* /pgstat.stat */
7622
7623                 sprintf(pgstat_stat_tmpname, "%s/pgstat.tmp", newval);
7624                 sprintf(pgstat_stat_filename, "%s/pgstat.stat", newval);
7625         }
7626
7627         return newval;
7628 }
7629
7630 #include "guc-file.c"