LCOV - code coverage report
Current view: top level - src/backend/commands - vacuum.c (source / functions) Coverage Total Hit
Test: PostgreSQL 19devel Lines: 89.1 % 762 679
Test Date: 2026-02-17 17:20:33 Functions: 95.5 % 22 21
Legend: Lines:     hit not hit

            Line data    Source code
       1              : /*-------------------------------------------------------------------------
       2              :  *
       3              :  * vacuum.c
       4              :  *    The postgres vacuum cleaner.
       5              :  *
       6              :  * This file includes (a) control and dispatch code for VACUUM and ANALYZE
       7              :  * commands, (b) code to compute various vacuum thresholds, and (c) index
       8              :  * vacuum code.
       9              :  *
      10              :  * VACUUM for heap AM is implemented in vacuumlazy.c, parallel vacuum in
      11              :  * vacuumparallel.c, ANALYZE in analyze.c, and VACUUM FULL is a variant of
      12              :  * CLUSTER, handled in cluster.c.
      13              :  *
      14              :  *
      15              :  * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
      16              :  * Portions Copyright (c) 1994, Regents of the University of California
      17              :  *
      18              :  *
      19              :  * IDENTIFICATION
      20              :  *    src/backend/commands/vacuum.c
      21              :  *
      22              :  *-------------------------------------------------------------------------
      23              :  */
      24              : #include "postgres.h"
      25              : 
      26              : #include <math.h>
      27              : 
      28              : #include "access/clog.h"
      29              : #include "access/commit_ts.h"
      30              : #include "access/genam.h"
      31              : #include "access/heapam.h"
      32              : #include "access/htup_details.h"
      33              : #include "access/multixact.h"
      34              : #include "access/tableam.h"
      35              : #include "access/transam.h"
      36              : #include "access/xact.h"
      37              : #include "catalog/namespace.h"
      38              : #include "catalog/pg_database.h"
      39              : #include "catalog/pg_inherits.h"
      40              : #include "commands/async.h"
      41              : #include "commands/cluster.h"
      42              : #include "commands/defrem.h"
      43              : #include "commands/progress.h"
      44              : #include "commands/vacuum.h"
      45              : #include "miscadmin.h"
      46              : #include "nodes/makefuncs.h"
      47              : #include "pgstat.h"
      48              : #include "postmaster/autovacuum.h"
      49              : #include "postmaster/bgworker_internals.h"
      50              : #include "postmaster/interrupt.h"
      51              : #include "storage/bufmgr.h"
      52              : #include "storage/lmgr.h"
      53              : #include "storage/pmsignal.h"
      54              : #include "storage/proc.h"
      55              : #include "storage/procarray.h"
      56              : #include "utils/acl.h"
      57              : #include "utils/fmgroids.h"
      58              : #include "utils/guc.h"
      59              : #include "utils/guc_hooks.h"
      60              : #include "utils/injection_point.h"
      61              : #include "utils/memutils.h"
      62              : #include "utils/snapmgr.h"
      63              : #include "utils/syscache.h"
      64              : 
      65              : /*
      66              :  * Minimum interval for cost-based vacuum delay reports from a parallel worker.
      67              :  * This aims to avoid sending too many messages and waking up the leader too
      68              :  * frequently.
      69              :  */
      70              : #define PARALLEL_VACUUM_DELAY_REPORT_INTERVAL_NS    (NS_PER_S)
      71              : 
      72              : /*
      73              :  * GUC parameters
      74              :  */
      75              : int         vacuum_freeze_min_age;
      76              : int         vacuum_freeze_table_age;
      77              : int         vacuum_multixact_freeze_min_age;
      78              : int         vacuum_multixact_freeze_table_age;
      79              : int         vacuum_failsafe_age;
      80              : int         vacuum_multixact_failsafe_age;
      81              : double      vacuum_max_eager_freeze_failure_rate;
      82              : bool        track_cost_delay_timing;
      83              : bool        vacuum_truncate;
      84              : 
      85              : /*
      86              :  * Variables for cost-based vacuum delay. The defaults differ between
      87              :  * autovacuum and vacuum. They should be set with the appropriate GUC value in
      88              :  * vacuum code. They are initialized here to the defaults for client backends
      89              :  * executing VACUUM or ANALYZE.
      90              :  */
      91              : double      vacuum_cost_delay = 0;
      92              : int         vacuum_cost_limit = 200;
      93              : 
      94              : /* Variable for reporting cost-based vacuum delay from parallel workers. */
      95              : int64       parallel_vacuum_worker_delay_ns = 0;
      96              : 
      97              : /*
      98              :  * VacuumFailsafeActive is a defined as a global so that we can determine
      99              :  * whether or not to re-enable cost-based vacuum delay when vacuuming a table.
     100              :  * If failsafe mode has been engaged, we will not re-enable cost-based delay
     101              :  * for the table until after vacuuming has completed, regardless of other
     102              :  * settings.
     103              :  *
     104              :  * Only VACUUM code should inspect this variable and only table access methods
     105              :  * should set it to true. In Table AM-agnostic VACUUM code, this variable is
     106              :  * inspected to determine whether or not to allow cost-based delays. Table AMs
     107              :  * are free to set it if they desire this behavior, but it is false by default
     108              :  * and reset to false in between vacuuming each relation.
     109              :  */
     110              : bool        VacuumFailsafeActive = false;
     111              : 
     112              : /*
     113              :  * Variables for cost-based parallel vacuum.  See comments atop
     114              :  * compute_parallel_delay to understand how it works.
     115              :  */
     116              : pg_atomic_uint32 *VacuumSharedCostBalance = NULL;
     117              : pg_atomic_uint32 *VacuumActiveNWorkers = NULL;
     118              : int         VacuumCostBalanceLocal = 0;
     119              : 
     120              : /* non-export function prototypes */
     121              : static List *expand_vacuum_rel(VacuumRelation *vrel,
     122              :                                MemoryContext vac_context, int options);
     123              : static List *get_all_vacuum_rels(MemoryContext vac_context, int options);
     124              : static void vac_truncate_clog(TransactionId frozenXID,
     125              :                               MultiXactId minMulti,
     126              :                               TransactionId lastSaneFrozenXid,
     127              :                               MultiXactId lastSaneMinMulti);
     128              : static bool vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
     129              :                        BufferAccessStrategy bstrategy);
     130              : static double compute_parallel_delay(void);
     131              : static VacOptValue get_vacoptval_from_boolean(DefElem *def);
     132              : static bool vac_tid_reaped(ItemPointer itemptr, void *state);
     133              : 
     134              : /*
     135              :  * GUC check function to ensure GUC value specified is within the allowable
     136              :  * range.
     137              :  */
     138              : bool
     139         1177 : check_vacuum_buffer_usage_limit(int *newval, void **extra,
     140              :                                 GucSource source)
     141              : {
     142              :     /* Value upper and lower hard limits are inclusive */
     143         1177 :     if (*newval == 0 || (*newval >= MIN_BAS_VAC_RING_SIZE_KB &&
     144         1177 :                          *newval <= MAX_BAS_VAC_RING_SIZE_KB))
     145         1177 :         return true;
     146              : 
     147              :     /* Value does not fall within any allowable range */
     148            0 :     GUC_check_errdetail("\"%s\" must be 0 or between %d kB and %d kB.",
     149              :                         "vacuum_buffer_usage_limit",
     150              :                         MIN_BAS_VAC_RING_SIZE_KB, MAX_BAS_VAC_RING_SIZE_KB);
     151              : 
     152            0 :     return false;
     153              : }
     154              : 
     155              : /*
     156              :  * Primary entry point for manual VACUUM and ANALYZE commands
     157              :  *
     158              :  * This is mainly a preparation wrapper for the real operations that will
     159              :  * happen in vacuum().
     160              :  */
     161              : void
     162         7421 : ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
     163              : {
     164              :     VacuumParams params;
     165         7421 :     BufferAccessStrategy bstrategy = NULL;
     166         7421 :     bool        verbose = false;
     167         7421 :     bool        skip_locked = false;
     168         7421 :     bool        analyze = false;
     169         7421 :     bool        freeze = false;
     170         7421 :     bool        full = false;
     171         7421 :     bool        disable_page_skipping = false;
     172         7421 :     bool        process_main = true;
     173         7421 :     bool        process_toast = true;
     174              :     int         ring_size;
     175         7421 :     bool        skip_database_stats = false;
     176         7421 :     bool        only_database_stats = false;
     177              :     MemoryContext vac_context;
     178              :     ListCell   *lc;
     179              : 
     180              :     /* index_cleanup and truncate values unspecified for now */
     181         7421 :     params.index_cleanup = VACOPTVALUE_UNSPECIFIED;
     182         7421 :     params.truncate = VACOPTVALUE_UNSPECIFIED;
     183              : 
     184              :     /* By default parallel vacuum is enabled */
     185         7421 :     params.nworkers = 0;
     186              : 
     187              :     /* Will be set later if we recurse to a TOAST table. */
     188         7421 :     params.toast_parent = InvalidOid;
     189              : 
     190              :     /*
     191              :      * Set this to an invalid value so it is clear whether or not a
     192              :      * BUFFER_USAGE_LIMIT was specified when making the access strategy.
     193              :      */
     194         7421 :     ring_size = -1;
     195              : 
     196              :     /* Parse options list */
     197        15599 :     foreach(lc, vacstmt->options)
     198              :     {
     199         8196 :         DefElem    *opt = (DefElem *) lfirst(lc);
     200              : 
     201              :         /* Parse common options for VACUUM and ANALYZE */
     202         8196 :         if (strcmp(opt->defname, "verbose") == 0)
     203           22 :             verbose = defGetBoolean(opt);
     204         8174 :         else if (strcmp(opt->defname, "skip_locked") == 0)
     205          167 :             skip_locked = defGetBoolean(opt);
     206         8007 :         else if (strcmp(opt->defname, "buffer_usage_limit") == 0)
     207              :         {
     208              :             const char *hintmsg;
     209              :             int         result;
     210              :             char       *vac_buffer_size;
     211              : 
     212           27 :             vac_buffer_size = defGetString(opt);
     213              : 
     214              :             /*
     215              :              * Check that the specified value is valid and the size falls
     216              :              * within the hard upper and lower limits if it is not 0.
     217              :              */
     218           27 :             if (!parse_int(vac_buffer_size, &result, GUC_UNIT_KB, &hintmsg) ||
     219           24 :                 (result != 0 &&
     220           18 :                  (result < MIN_BAS_VAC_RING_SIZE_KB || result > MAX_BAS_VAC_RING_SIZE_KB)))
     221              :             {
     222            9 :                 ereport(ERROR,
     223              :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     224              :                          errmsg("%s option must be 0 or between %d kB and %d kB",
     225              :                                 "BUFFER_USAGE_LIMIT",
     226              :                                 MIN_BAS_VAC_RING_SIZE_KB, MAX_BAS_VAC_RING_SIZE_KB),
     227              :                          hintmsg ? errhint_internal("%s", _(hintmsg)) : 0));
     228              :             }
     229              : 
     230           18 :             ring_size = result;
     231              :         }
     232         7980 :         else if (!vacstmt->is_vacuumcmd)
     233            3 :             ereport(ERROR,
     234              :                     (errcode(ERRCODE_SYNTAX_ERROR),
     235              :                      errmsg("unrecognized %s option \"%s\"",
     236              :                             "ANALYZE", opt->defname),
     237              :                      parser_errposition(pstate, opt->location)));
     238              : 
     239              :         /* Parse options available on VACUUM */
     240         7977 :         else if (strcmp(opt->defname, "analyze") == 0)
     241         1517 :             analyze = defGetBoolean(opt);
     242         6460 :         else if (strcmp(opt->defname, "freeze") == 0)
     243         1618 :             freeze = defGetBoolean(opt);
     244         4842 :         else if (strcmp(opt->defname, "full") == 0)
     245          196 :             full = defGetBoolean(opt);
     246         4646 :         else if (strcmp(opt->defname, "disable_page_skipping") == 0)
     247          107 :             disable_page_skipping = defGetBoolean(opt);
     248         4539 :         else if (strcmp(opt->defname, "index_cleanup") == 0)
     249              :         {
     250              :             /* Interpret no string as the default, which is 'auto' */
     251           87 :             if (!opt->arg)
     252            0 :                 params.index_cleanup = VACOPTVALUE_AUTO;
     253              :             else
     254              :             {
     255           87 :                 char       *sval = defGetString(opt);
     256              : 
     257              :                 /* Try matching on 'auto' string, or fall back on boolean */
     258           87 :                 if (pg_strcasecmp(sval, "auto") == 0)
     259            3 :                     params.index_cleanup = VACOPTVALUE_AUTO;
     260              :                 else
     261           84 :                     params.index_cleanup = get_vacoptval_from_boolean(opt);
     262              :             }
     263              :         }
     264         4452 :         else if (strcmp(opt->defname, "process_main") == 0)
     265           77 :             process_main = defGetBoolean(opt);
     266         4375 :         else if (strcmp(opt->defname, "process_toast") == 0)
     267           80 :             process_toast = defGetBoolean(opt);
     268         4295 :         else if (strcmp(opt->defname, "truncate") == 0)
     269           80 :             params.truncate = get_vacoptval_from_boolean(opt);
     270         4215 :         else if (strcmp(opt->defname, "parallel") == 0)
     271              :         {
     272          176 :             int         nworkers = defGetInt32(opt);
     273              : 
     274          173 :             if (nworkers < 0 || nworkers > MAX_PARALLEL_WORKER_LIMIT)
     275            3 :                 ereport(ERROR,
     276              :                         (errcode(ERRCODE_SYNTAX_ERROR),
     277              :                          errmsg("%s option must be between 0 and %d",
     278              :                                 "PARALLEL",
     279              :                                 MAX_PARALLEL_WORKER_LIMIT),
     280              :                          parser_errposition(pstate, opt->location)));
     281              : 
     282              :             /*
     283              :              * Disable parallel vacuum, if user has specified parallel degree
     284              :              * as zero.
     285              :              */
     286          170 :             if (nworkers == 0)
     287           78 :                 params.nworkers = -1;
     288              :             else
     289           92 :                 params.nworkers = nworkers;
     290              :         }
     291         4039 :         else if (strcmp(opt->defname, "skip_database_stats") == 0)
     292         3967 :             skip_database_stats = defGetBoolean(opt);
     293           72 :         else if (strcmp(opt->defname, "only_database_stats") == 0)
     294           72 :             only_database_stats = defGetBoolean(opt);
     295              :         else
     296            0 :             ereport(ERROR,
     297              :                     (errcode(ERRCODE_SYNTAX_ERROR),
     298              :                      errmsg("unrecognized %s option \"%s\"",
     299              :                             "VACUUM", opt->defname),
     300              :                      parser_errposition(pstate, opt->location)));
     301              :     }
     302              : 
     303              :     /* Set vacuum options */
     304         7403 :     params.options =
     305         7403 :         (vacstmt->is_vacuumcmd ? VACOPT_VACUUM : VACOPT_ANALYZE) |
     306         7403 :         (verbose ? VACOPT_VERBOSE : 0) |
     307         7403 :         (skip_locked ? VACOPT_SKIP_LOCKED : 0) |
     308         7403 :         (analyze ? VACOPT_ANALYZE : 0) |
     309         7403 :         (freeze ? VACOPT_FREEZE : 0) |
     310         7403 :         (full ? VACOPT_FULL : 0) |
     311         7403 :         (disable_page_skipping ? VACOPT_DISABLE_PAGE_SKIPPING : 0) |
     312         7403 :         (process_main ? VACOPT_PROCESS_MAIN : 0) |
     313         7403 :         (process_toast ? VACOPT_PROCESS_TOAST : 0) |
     314         7403 :         (skip_database_stats ? VACOPT_SKIP_DATABASE_STATS : 0) |
     315         7403 :         (only_database_stats ? VACOPT_ONLY_DATABASE_STATS : 0);
     316              : 
     317              :     /* sanity checks on options */
     318              :     Assert(params.options & (VACOPT_VACUUM | VACOPT_ANALYZE));
     319              :     Assert((params.options & VACOPT_VACUUM) ||
     320              :            !(params.options & (VACOPT_FULL | VACOPT_FREEZE)));
     321              : 
     322         7403 :     if ((params.options & VACOPT_FULL) && params.nworkers > 0)
     323            3 :         ereport(ERROR,
     324              :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     325              :                  errmsg("VACUUM FULL cannot be performed in parallel")));
     326              : 
     327              :     /*
     328              :      * BUFFER_USAGE_LIMIT does nothing for VACUUM (FULL) so just raise an
     329              :      * ERROR for that case.  VACUUM (FULL, ANALYZE) does make use of it, so
     330              :      * we'll permit that.
     331              :      */
     332         7400 :     if (ring_size != -1 && (params.options & VACOPT_FULL) &&
     333            3 :         !(params.options & VACOPT_ANALYZE))
     334            3 :         ereport(ERROR,
     335              :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     336              :                  errmsg("BUFFER_USAGE_LIMIT cannot be specified for VACUUM FULL")));
     337              : 
     338              :     /*
     339              :      * Make sure VACOPT_ANALYZE is specified if any column lists are present.
     340              :      */
     341         7397 :     if (!(params.options & VACOPT_ANALYZE))
     342              :     {
     343         6706 :         foreach(lc, vacstmt->rels)
     344              :         {
     345         3301 :             VacuumRelation *vrel = lfirst_node(VacuumRelation, lc);
     346              : 
     347         3301 :             if (vrel->va_cols != NIL)
     348            3 :                 ereport(ERROR,
     349              :                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     350              :                          errmsg("ANALYZE option must be specified when a column list is provided")));
     351              :         }
     352              :     }
     353              : 
     354              : 
     355              :     /*
     356              :      * Sanity check DISABLE_PAGE_SKIPPING option.
     357              :      */
     358         7394 :     if ((params.options & VACOPT_FULL) != 0 &&
     359          184 :         (params.options & VACOPT_DISABLE_PAGE_SKIPPING) != 0)
     360            0 :         ereport(ERROR,
     361              :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     362              :                  errmsg("VACUUM option DISABLE_PAGE_SKIPPING cannot be used with FULL")));
     363              : 
     364              :     /* sanity check for PROCESS_TOAST */
     365         7394 :     if ((params.options & VACOPT_FULL) != 0 &&
     366          184 :         (params.options & VACOPT_PROCESS_TOAST) == 0)
     367            3 :         ereport(ERROR,
     368              :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     369              :                  errmsg("PROCESS_TOAST required with VACUUM FULL")));
     370              : 
     371              :     /* sanity check for ONLY_DATABASE_STATS */
     372         7391 :     if (params.options & VACOPT_ONLY_DATABASE_STATS)
     373              :     {
     374              :         Assert(params.options & VACOPT_VACUUM);
     375           72 :         if (vacstmt->rels != NIL)
     376            3 :             ereport(ERROR,
     377              :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     378              :                      errmsg("ONLY_DATABASE_STATS cannot be specified with a list of tables")));
     379              :         /* don't require people to turn off PROCESS_TOAST/MAIN explicitly */
     380           69 :         if (params.options & ~(VACOPT_VACUUM |
     381              :                                VACOPT_VERBOSE |
     382              :                                VACOPT_PROCESS_MAIN |
     383              :                                VACOPT_PROCESS_TOAST |
     384              :                                VACOPT_ONLY_DATABASE_STATS))
     385            0 :             ereport(ERROR,
     386              :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     387              :                      errmsg("ONLY_DATABASE_STATS cannot be specified with other VACUUM options")));
     388              :     }
     389              : 
     390              :     /*
     391              :      * All freeze ages are zero if the FREEZE option is given; otherwise pass
     392              :      * them as -1 which means to use the default values.
     393              :      */
     394         7388 :     if (params.options & VACOPT_FREEZE)
     395              :     {
     396         1618 :         params.freeze_min_age = 0;
     397         1618 :         params.freeze_table_age = 0;
     398         1618 :         params.multixact_freeze_min_age = 0;
     399         1618 :         params.multixact_freeze_table_age = 0;
     400              :     }
     401              :     else
     402              :     {
     403         5770 :         params.freeze_min_age = -1;
     404         5770 :         params.freeze_table_age = -1;
     405         5770 :         params.multixact_freeze_min_age = -1;
     406         5770 :         params.multixact_freeze_table_age = -1;
     407              :     }
     408              : 
     409              :     /* user-invoked vacuum is never "for wraparound" */
     410         7388 :     params.is_wraparound = false;
     411              : 
     412              :     /*
     413              :      * user-invoked vacuum uses VACOPT_VERBOSE instead of
     414              :      * log_vacuum_min_duration and log_analyze_min_duration
     415              :      */
     416         7388 :     params.log_vacuum_min_duration = -1;
     417         7388 :     params.log_analyze_min_duration = -1;
     418              : 
     419              :     /*
     420              :      * Later, in vacuum_rel(), we check if a reloption override was specified.
     421              :      */
     422         7388 :     params.max_eager_freeze_failure_rate = vacuum_max_eager_freeze_failure_rate;
     423              : 
     424              :     /*
     425              :      * Create special memory context for cross-transaction storage.
     426              :      *
     427              :      * Since it is a child of PortalContext, it will go away eventually even
     428              :      * if we suffer an error; there's no need for special abort cleanup logic.
     429              :      */
     430         7388 :     vac_context = AllocSetContextCreate(PortalContext,
     431              :                                         "Vacuum",
     432              :                                         ALLOCSET_DEFAULT_SIZES);
     433              : 
     434              :     /*
     435              :      * Make a buffer strategy object in the cross-transaction memory context.
     436              :      * We needn't bother making this for VACUUM (FULL) or VACUUM
     437              :      * (ONLY_DATABASE_STATS) as they'll not make use of it.  VACUUM (FULL,
     438              :      * ANALYZE) is possible, so we'd better ensure that we make a strategy
     439              :      * when we see ANALYZE.
     440              :      */
     441         7388 :     if ((params.options & (VACOPT_ONLY_DATABASE_STATS |
     442          250 :                            VACOPT_FULL)) == 0 ||
     443          250 :         (params.options & VACOPT_ANALYZE) != 0)
     444              :     {
     445              : 
     446         7141 :         MemoryContext old_context = MemoryContextSwitchTo(vac_context);
     447              : 
     448              :         Assert(ring_size >= -1);
     449              : 
     450              :         /*
     451              :          * If BUFFER_USAGE_LIMIT was specified by the VACUUM or ANALYZE
     452              :          * command, it overrides the value of VacuumBufferUsageLimit.  Either
     453              :          * value may be 0, in which case GetAccessStrategyWithSize() will
     454              :          * return NULL, effectively allowing full use of shared buffers.
     455              :          */
     456         7141 :         if (ring_size == -1)
     457         7126 :             ring_size = VacuumBufferUsageLimit;
     458              : 
     459         7141 :         bstrategy = GetAccessStrategyWithSize(BAS_VACUUM, ring_size);
     460              : 
     461         7141 :         MemoryContextSwitchTo(old_context);
     462              :     }
     463              : 
     464              :     /* Now go through the common routine */
     465         7388 :     vacuum(vacstmt->rels, params, bstrategy, vac_context, isTopLevel);
     466              : 
     467              :     /* Finally, clean up the vacuum memory context */
     468         7322 :     MemoryContextDelete(vac_context);
     469         7322 : }
     470              : 
     471              : /*
     472              :  * Internal entry point for autovacuum and the VACUUM / ANALYZE commands.
     473              :  *
     474              :  * relations, if not NIL, is a list of VacuumRelation to process; otherwise,
     475              :  * we process all relevant tables in the database.  For each VacuumRelation,
     476              :  * if a valid OID is supplied, the table with that OID is what to process;
     477              :  * otherwise, the VacuumRelation's RangeVar indicates what to process.
     478              :  *
     479              :  * params contains a set of parameters that can be used to customize the
     480              :  * behavior.
     481              :  *
     482              :  * bstrategy may be passed in as NULL when the caller does not want to
     483              :  * restrict the number of shared_buffers that VACUUM / ANALYZE can use,
     484              :  * otherwise, the caller must build a BufferAccessStrategy with the number of
     485              :  * shared_buffers that VACUUM / ANALYZE should try to limit themselves to
     486              :  * using.
     487              :  *
     488              :  * isTopLevel should be passed down from ProcessUtility.
     489              :  *
     490              :  * It is the caller's responsibility that all parameters are allocated in a
     491              :  * memory context that will not disappear at transaction commit.
     492              :  */
     493              : void
     494       109948 : vacuum(List *relations, const VacuumParams params, BufferAccessStrategy bstrategy,
     495              :        MemoryContext vac_context, bool isTopLevel)
     496              : {
     497              :     static bool in_vacuum = false;
     498              : 
     499              :     const char *stmttype;
     500              :     volatile bool in_outer_xact,
     501              :                 use_own_xacts;
     502              : 
     503       109948 :     stmttype = (params.options & VACOPT_VACUUM) ? "VACUUM" : "ANALYZE";
     504              : 
     505              :     /*
     506              :      * We cannot run VACUUM inside a user transaction block; if we were inside
     507              :      * a transaction, then our commit- and start-transaction-command calls
     508              :      * would not have the intended effect!  There are numerous other subtle
     509              :      * dependencies on this, too.
     510              :      *
     511              :      * ANALYZE (without VACUUM) can run either way.
     512              :      */
     513       109948 :     if (params.options & VACOPT_VACUUM)
     514              :     {
     515       107301 :         PreventInTransactionBlock(isTopLevel, stmttype);
     516       107291 :         in_outer_xact = false;
     517              :     }
     518              :     else
     519         2647 :         in_outer_xact = IsInTransactionBlock(isTopLevel);
     520              : 
     521              :     /*
     522              :      * Check for and disallow recursive calls.  This could happen when VACUUM
     523              :      * FULL or ANALYZE calls a hostile index expression that itself calls
     524              :      * ANALYZE.
     525              :      */
     526       109938 :     if (in_vacuum)
     527            6 :         ereport(ERROR,
     528              :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     529              :                  errmsg("%s cannot be executed from VACUUM or ANALYZE",
     530              :                         stmttype)));
     531              : 
     532              :     /*
     533              :      * Build list of relation(s) to process, putting any new data in
     534              :      * vac_context for safekeeping.
     535              :      */
     536       109932 :     if (params.options & VACOPT_ONLY_DATABASE_STATS)
     537              :     {
     538              :         /* We don't process any tables in this case */
     539              :         Assert(relations == NIL);
     540              :     }
     541       109863 :     else if (relations != NIL)
     542              :     {
     543       109752 :         List       *newrels = NIL;
     544              :         ListCell   *lc;
     545              : 
     546       219571 :         foreach(lc, relations)
     547              :         {
     548       109837 :             VacuumRelation *vrel = lfirst_node(VacuumRelation, lc);
     549              :             List       *sublist;
     550              :             MemoryContext old_context;
     551              : 
     552       109837 :             sublist = expand_vacuum_rel(vrel, vac_context, params.options);
     553       109819 :             old_context = MemoryContextSwitchTo(vac_context);
     554       109819 :             newrels = list_concat(newrels, sublist);
     555       109819 :             MemoryContextSwitchTo(old_context);
     556              :         }
     557       109734 :         relations = newrels;
     558              :     }
     559              :     else
     560          111 :         relations = get_all_vacuum_rels(vac_context, params.options);
     561              : 
     562              :     /*
     563              :      * Decide whether we need to start/commit our own transactions.
     564              :      *
     565              :      * For VACUUM (with or without ANALYZE): always do so, so that we can
     566              :      * release locks as soon as possible.  (We could possibly use the outer
     567              :      * transaction for a one-table VACUUM, but handling TOAST tables would be
     568              :      * problematic.)
     569              :      *
     570              :      * For ANALYZE (no VACUUM): if inside a transaction block, we cannot
     571              :      * start/commit our own transactions.  Also, there's no need to do so if
     572              :      * only processing one relation.  For multiple relations when not within a
     573              :      * transaction block, and also in an autovacuum worker, use own
     574              :      * transactions so we can release locks sooner.
     575              :      */
     576       109914 :     if (params.options & VACOPT_VACUUM)
     577       107285 :         use_own_xacts = true;
     578              :     else
     579              :     {
     580              :         Assert(params.options & VACOPT_ANALYZE);
     581         2629 :         if (AmAutoVacuumWorkerProcess())
     582          175 :             use_own_xacts = true;
     583         2454 :         else if (in_outer_xact)
     584          130 :             use_own_xacts = false;
     585         2324 :         else if (list_length(relations) > 1)
     586          406 :             use_own_xacts = true;
     587              :         else
     588         1918 :             use_own_xacts = false;
     589              :     }
     590              : 
     591              :     /*
     592              :      * vacuum_rel expects to be entered with no transaction active; it will
     593              :      * start and commit its own transaction.  But we are called by an SQL
     594              :      * command, and so we are executing inside a transaction already. We
     595              :      * commit the transaction started in PostgresMain() here, and start
     596              :      * another one before exiting to match the commit waiting for us back in
     597              :      * PostgresMain().
     598              :      */
     599       109914 :     if (use_own_xacts)
     600              :     {
     601              :         Assert(!in_outer_xact);
     602              : 
     603              :         /* ActiveSnapshot is not set by autovacuum */
     604       107866 :         if (ActiveSnapshotSet())
     605         5306 :             PopActiveSnapshot();
     606              : 
     607              :         /* matches the StartTransaction in PostgresMain() */
     608       107866 :         CommitTransactionCommand();
     609              :     }
     610              : 
     611              :     /* Turn vacuum cost accounting on or off, and set/clear in_vacuum */
     612       109914 :     PG_TRY();
     613              :     {
     614              :         ListCell   *cur;
     615              : 
     616       109914 :         in_vacuum = true;
     617       109914 :         VacuumFailsafeActive = false;
     618       109914 :         VacuumUpdateCosts();
     619       109914 :         VacuumCostBalance = 0;
     620       109914 :         VacuumCostBalanceLocal = 0;
     621       109914 :         VacuumSharedCostBalance = NULL;
     622       109914 :         VacuumActiveNWorkers = NULL;
     623              : 
     624              :         /*
     625              :          * Loop to process each selected relation.
     626              :          */
     627       228508 :         foreach(cur, relations)
     628              :         {
     629       118626 :             VacuumRelation *vrel = lfirst_node(VacuumRelation, cur);
     630              : 
     631       118626 :             if (params.options & VACOPT_VACUUM)
     632              :             {
     633       111760 :                 if (!vacuum_rel(vrel->oid, vrel->relation, params, bstrategy))
     634           50 :                     continue;
     635              :             }
     636              : 
     637       118573 :             if (params.options & VACOPT_ANALYZE)
     638              :             {
     639              :                 /*
     640              :                  * If using separate xacts, start one for analyze. Otherwise,
     641              :                  * we can use the outer transaction.
     642              :                  */
     643         8529 :                 if (use_own_xacts)
     644              :                 {
     645         6491 :                     StartTransactionCommand();
     646              :                     /* functions in indexes may want a snapshot set */
     647         6491 :                     PushActiveSnapshot(GetTransactionSnapshot());
     648              :                 }
     649              : 
     650         8529 :                 analyze_rel(vrel->oid, vrel->relation, params,
     651              :                             vrel->va_cols, in_outer_xact, bstrategy);
     652              : 
     653         8500 :                 if (use_own_xacts)
     654              :                 {
     655         6472 :                     PopActiveSnapshot();
     656              :                     /* standard_ProcessUtility() does CCI if !use_own_xacts */
     657         6472 :                     CommandCounterIncrement();
     658         6472 :                     CommitTransactionCommand();
     659              :                 }
     660              :                 else
     661              :                 {
     662              :                     /*
     663              :                      * If we're not using separate xacts, better separate the
     664              :                      * ANALYZE actions with CCIs.  This avoids trouble if user
     665              :                      * says "ANALYZE t, t".
     666              :                      */
     667         2028 :                     CommandCounterIncrement();
     668              :                 }
     669              :             }
     670              : 
     671              :             /*
     672              :              * Ensure VacuumFailsafeActive has been reset before vacuuming the
     673              :              * next relation.
     674              :              */
     675       118544 :             VacuumFailsafeActive = false;
     676              :         }
     677              :     }
     678           32 :     PG_FINALLY();
     679              :     {
     680       109914 :         in_vacuum = false;
     681       109914 :         VacuumCostActive = false;
     682       109914 :         VacuumFailsafeActive = false;
     683       109914 :         VacuumCostBalance = 0;
     684              :     }
     685       109914 :     PG_END_TRY();
     686              : 
     687              :     /*
     688              :      * Finish up processing.
     689              :      */
     690       109882 :     if (use_own_xacts)
     691              :     {
     692              :         /* here, we are not in a transaction */
     693              : 
     694              :         /*
     695              :          * This matches the CommitTransaction waiting for us in
     696              :          * PostgresMain().
     697              :          */
     698       107844 :         StartTransactionCommand();
     699              :     }
     700              : 
     701       109882 :     if ((params.options & VACOPT_VACUUM) &&
     702       107269 :         !(params.options & VACOPT_SKIP_DATABASE_STATS))
     703              :     {
     704              :         /*
     705              :          * Update pg_database.datfrozenxid, and truncate pg_xact if possible.
     706              :          */
     707          918 :         vac_update_datfrozenxid();
     708              :     }
     709              : 
     710       109882 : }
     711              : 
     712              : /*
     713              :  * Check if the current user has privileges to vacuum or analyze the relation.
     714              :  * If not, issue a WARNING log message and return false to let the caller
     715              :  * decide what to do with this relation.  This routine is used to decide if a
     716              :  * relation can be processed for VACUUM or ANALYZE.
     717              :  */
     718              : bool
     719       141662 : vacuum_is_permitted_for_relation(Oid relid, Form_pg_class reltuple,
     720              :                                  bits32 options)
     721              : {
     722              :     char       *relname;
     723              : 
     724              :     Assert((options & (VACOPT_VACUUM | VACOPT_ANALYZE)) != 0);
     725              : 
     726              :     /*----------
     727              :      * A role has privileges to vacuum or analyze the relation if any of the
     728              :      * following are true:
     729              :      *   - the role owns the current database and the relation is not shared
     730              :      *   - the role has the MAINTAIN privilege on the relation
     731              :      *----------
     732              :      */
     733       141662 :     if ((object_ownercheck(DatabaseRelationId, MyDatabaseId, GetUserId()) &&
     734       163814 :          !reltuple->relisshared) ||
     735        23937 :         pg_class_aclcheck(relid, GetUserId(), ACL_MAINTAIN) == ACLCHECK_OK)
     736       140115 :         return true;
     737              : 
     738         1547 :     relname = NameStr(reltuple->relname);
     739              : 
     740         1547 :     if ((options & VACOPT_VACUUM) != 0)
     741              :     {
     742          112 :         ereport(WARNING,
     743              :                 (errmsg("permission denied to vacuum \"%s\", skipping it",
     744              :                         relname)));
     745              : 
     746              :         /*
     747              :          * For VACUUM ANALYZE, both logs could show up, but just generate
     748              :          * information for VACUUM as that would be the first one to be
     749              :          * processed.
     750              :          */
     751          112 :         return false;
     752              :     }
     753              : 
     754         1435 :     if ((options & VACOPT_ANALYZE) != 0)
     755         1435 :         ereport(WARNING,
     756              :                 (errmsg("permission denied to analyze \"%s\", skipping it",
     757              :                         relname)));
     758              : 
     759         1435 :     return false;
     760              : }
     761              : 
     762              : 
     763              : /*
     764              :  * vacuum_open_relation
     765              :  *
     766              :  * This routine is used for attempting to open and lock a relation which
     767              :  * is going to be vacuumed or analyzed.  If the relation cannot be opened
     768              :  * or locked, a log is emitted if possible.
     769              :  */
     770              : Relation
     771       125190 : vacuum_open_relation(Oid relid, RangeVar *relation, bits32 options,
     772              :                      bool verbose, LOCKMODE lmode)
     773              : {
     774              :     Relation    rel;
     775       125190 :     bool        rel_lock = true;
     776              :     int         elevel;
     777              : 
     778              :     Assert((options & (VACOPT_VACUUM | VACOPT_ANALYZE)) != 0);
     779              : 
     780              :     /*
     781              :      * Open the relation and get the appropriate lock on it.
     782              :      *
     783              :      * There's a race condition here: the relation may have gone away since
     784              :      * the last time we saw it.  If so, we don't need to vacuum or analyze it.
     785              :      *
     786              :      * If we've been asked not to wait for the relation lock, acquire it first
     787              :      * in non-blocking mode, before calling try_relation_open().
     788              :      */
     789       125190 :     if (!(options & VACOPT_SKIP_LOCKED))
     790       124532 :         rel = try_relation_open(relid, lmode);
     791          658 :     else if (ConditionalLockRelationOid(relid, lmode))
     792          648 :         rel = try_relation_open(relid, NoLock);
     793              :     else
     794              :     {
     795           10 :         rel = NULL;
     796           10 :         rel_lock = false;
     797              :     }
     798              : 
     799              :     /* if relation is opened, leave */
     800       125190 :     if (rel)
     801       125174 :         return rel;
     802              : 
     803              :     /*
     804              :      * Relation could not be opened, hence generate if possible a log
     805              :      * informing on the situation.
     806              :      *
     807              :      * If the RangeVar is not defined, we do not have enough information to
     808              :      * provide a meaningful log statement.  Chances are that the caller has
     809              :      * intentionally not provided this information so that this logging is
     810              :      * skipped, anyway.
     811              :      */
     812           16 :     if (relation == NULL)
     813            9 :         return NULL;
     814              : 
     815              :     /*
     816              :      * Determine the log level.
     817              :      *
     818              :      * For manual VACUUM or ANALYZE, we emit a WARNING to match the log
     819              :      * statements in the permission checks; otherwise, only log if the caller
     820              :      * so requested.
     821              :      */
     822            7 :     if (!AmAutoVacuumWorkerProcess())
     823            7 :         elevel = WARNING;
     824            0 :     else if (verbose)
     825            0 :         elevel = LOG;
     826              :     else
     827            0 :         return NULL;
     828              : 
     829            7 :     if ((options & VACOPT_VACUUM) != 0)
     830              :     {
     831            5 :         if (!rel_lock)
     832            3 :             ereport(elevel,
     833              :                     (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
     834              :                      errmsg("skipping vacuum of \"%s\" --- lock not available",
     835              :                             relation->relname)));
     836              :         else
     837            2 :             ereport(elevel,
     838              :                     (errcode(ERRCODE_UNDEFINED_TABLE),
     839              :                      errmsg("skipping vacuum of \"%s\" --- relation no longer exists",
     840              :                             relation->relname)));
     841              : 
     842              :         /*
     843              :          * For VACUUM ANALYZE, both logs could show up, but just generate
     844              :          * information for VACUUM as that would be the first one to be
     845              :          * processed.
     846              :          */
     847            5 :         return NULL;
     848              :     }
     849              : 
     850            2 :     if ((options & VACOPT_ANALYZE) != 0)
     851              :     {
     852            2 :         if (!rel_lock)
     853            1 :             ereport(elevel,
     854              :                     (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
     855              :                      errmsg("skipping analyze of \"%s\" --- lock not available",
     856              :                             relation->relname)));
     857              :         else
     858            1 :             ereport(elevel,
     859              :                     (errcode(ERRCODE_UNDEFINED_TABLE),
     860              :                      errmsg("skipping analyze of \"%s\" --- relation no longer exists",
     861              :                             relation->relname)));
     862              :     }
     863              : 
     864            2 :     return NULL;
     865              : }
     866              : 
     867              : 
     868              : /*
     869              :  * Given a VacuumRelation, fill in the table OID if it wasn't specified,
     870              :  * and optionally add VacuumRelations for partitions or inheritance children.
     871              :  *
     872              :  * If a VacuumRelation does not have an OID supplied and is a partitioned
     873              :  * table, an extra entry will be added to the output for each partition.
     874              :  * Presently, only autovacuum supplies OIDs when calling vacuum(), and
     875              :  * it does not want us to expand partitioned tables.
     876              :  *
     877              :  * We take care not to modify the input data structure, but instead build
     878              :  * new VacuumRelation(s) to return.  (But note that they will reference
     879              :  * unmodified parts of the input, eg column lists.)  New data structures
     880              :  * are made in vac_context.
     881              :  */
     882              : static List *
     883       109837 : expand_vacuum_rel(VacuumRelation *vrel, MemoryContext vac_context,
     884              :                   int options)
     885              : {
     886       109837 :     List       *vacrels = NIL;
     887              :     MemoryContext oldcontext;
     888              : 
     889              :     /* If caller supplied OID, there's nothing we need do here. */
     890       109837 :     if (OidIsValid(vrel->oid))
     891              :     {
     892       102560 :         oldcontext = MemoryContextSwitchTo(vac_context);
     893       102560 :         vacrels = lappend(vacrels, vrel);
     894       102560 :         MemoryContextSwitchTo(oldcontext);
     895              :     }
     896              :     else
     897              :     {
     898              :         /*
     899              :          * Process a specific relation, and possibly partitions or child
     900              :          * tables thereof.
     901              :          */
     902              :         Oid         relid;
     903              :         HeapTuple   tuple;
     904              :         Form_pg_class classForm;
     905              :         bool        include_children;
     906              :         bool        is_partitioned_table;
     907              :         int         rvr_opts;
     908              : 
     909              :         /*
     910              :          * Since autovacuum workers supply OIDs when calling vacuum(), no
     911              :          * autovacuum worker should reach this code.
     912              :          */
     913              :         Assert(!AmAutoVacuumWorkerProcess());
     914              : 
     915              :         /*
     916              :          * We transiently take AccessShareLock to protect the syscache lookup
     917              :          * below, as well as find_all_inheritors's expectation that the caller
     918              :          * holds some lock on the starting relation.
     919              :          */
     920         7277 :         rvr_opts = (options & VACOPT_SKIP_LOCKED) ? RVR_SKIP_LOCKED : 0;
     921         7277 :         relid = RangeVarGetRelidExtended(vrel->relation,
     922              :                                          AccessShareLock,
     923              :                                          rvr_opts,
     924              :                                          NULL, NULL);
     925              : 
     926              :         /*
     927              :          * If the lock is unavailable, emit the same log statement that
     928              :          * vacuum_rel() and analyze_rel() would.
     929              :          */
     930         7259 :         if (!OidIsValid(relid))
     931              :         {
     932            4 :             if (options & VACOPT_VACUUM)
     933            3 :                 ereport(WARNING,
     934              :                         (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
     935              :                          errmsg("skipping vacuum of \"%s\" --- lock not available",
     936              :                                 vrel->relation->relname)));
     937              :             else
     938            1 :                 ereport(WARNING,
     939              :                         (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
     940              :                          errmsg("skipping analyze of \"%s\" --- lock not available",
     941              :                                 vrel->relation->relname)));
     942            4 :             return vacrels;
     943              :         }
     944              : 
     945              :         /*
     946              :          * To check whether the relation is a partitioned table and its
     947              :          * ownership, fetch its syscache entry.
     948              :          */
     949         7255 :         tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
     950         7255 :         if (!HeapTupleIsValid(tuple))
     951            0 :             elog(ERROR, "cache lookup failed for relation %u", relid);
     952         7255 :         classForm = (Form_pg_class) GETSTRUCT(tuple);
     953              : 
     954              :         /*
     955              :          * Make a returnable VacuumRelation for this rel if the user has the
     956              :          * required privileges.
     957              :          */
     958         7255 :         if (vacuum_is_permitted_for_relation(relid, classForm, options))
     959              :         {
     960         7139 :             oldcontext = MemoryContextSwitchTo(vac_context);
     961         7139 :             vacrels = lappend(vacrels, makeVacuumRelation(vrel->relation,
     962              :                                                           relid,
     963              :                                                           vrel->va_cols));
     964         7139 :             MemoryContextSwitchTo(oldcontext);
     965              :         }
     966              : 
     967              :         /*
     968              :          * Vacuuming a partitioned table with ONLY will not do anything since
     969              :          * the partitioned table itself is empty.  Issue a warning if the user
     970              :          * requests this.
     971              :          */
     972         7255 :         include_children = vrel->relation->inh;
     973         7255 :         is_partitioned_table = (classForm->relkind == RELKIND_PARTITIONED_TABLE);
     974         7255 :         if ((options & VACOPT_VACUUM) && is_partitioned_table && !include_children)
     975            3 :             ereport(WARNING,
     976              :                     (errmsg("VACUUM ONLY of partitioned table \"%s\" has no effect",
     977              :                             vrel->relation->relname)));
     978              : 
     979         7255 :         ReleaseSysCache(tuple);
     980              : 
     981              :         /*
     982              :          * Unless the user has specified ONLY, make relation list entries for
     983              :          * its partitions or inheritance child tables.  Note that the list
     984              :          * returned by find_all_inheritors() includes the passed-in OID, so we
     985              :          * have to skip that.  There's no point in taking locks on the
     986              :          * individual partitions or child tables yet, and doing so would just
     987              :          * add unnecessary deadlock risk.  For this last reason, we do not yet
     988              :          * check the ownership of the partitions/tables, which get added to
     989              :          * the list to process.  Ownership will be checked later on anyway.
     990              :          */
     991         7255 :         if (include_children)
     992              :         {
     993         7240 :             List       *part_oids = find_all_inheritors(relid, NoLock, NULL);
     994              :             ListCell   *part_lc;
     995              : 
     996        15575 :             foreach(part_lc, part_oids)
     997              :             {
     998         8335 :                 Oid         part_oid = lfirst_oid(part_lc);
     999              : 
    1000         8335 :                 if (part_oid == relid)
    1001         7240 :                     continue;   /* ignore original table */
    1002              : 
    1003              :                 /*
    1004              :                  * We omit a RangeVar since it wouldn't be appropriate to
    1005              :                  * complain about failure to open one of these relations
    1006              :                  * later.
    1007              :                  */
    1008         1095 :                 oldcontext = MemoryContextSwitchTo(vac_context);
    1009         1095 :                 vacrels = lappend(vacrels, makeVacuumRelation(NULL,
    1010              :                                                               part_oid,
    1011              :                                                               vrel->va_cols));
    1012         1095 :                 MemoryContextSwitchTo(oldcontext);
    1013              :             }
    1014              :         }
    1015              : 
    1016              :         /*
    1017              :          * Release lock again.  This means that by the time we actually try to
    1018              :          * process the table, it might be gone or renamed.  In the former case
    1019              :          * we'll silently ignore it; in the latter case we'll process it
    1020              :          * anyway, but we must beware that the RangeVar doesn't necessarily
    1021              :          * identify it anymore.  This isn't ideal, perhaps, but there's little
    1022              :          * practical alternative, since we're typically going to commit this
    1023              :          * transaction and begin a new one between now and then.  Moreover,
    1024              :          * holding locks on multiple relations would create significant risk
    1025              :          * of deadlock.
    1026              :          */
    1027         7255 :         UnlockRelationOid(relid, AccessShareLock);
    1028              :     }
    1029              : 
    1030       109815 :     return vacrels;
    1031              : }
    1032              : 
    1033              : /*
    1034              :  * Construct a list of VacuumRelations for all vacuumable rels in
    1035              :  * the current database.  The list is built in vac_context.
    1036              :  */
    1037              : static List *
    1038          111 : get_all_vacuum_rels(MemoryContext vac_context, int options)
    1039              : {
    1040          111 :     List       *vacrels = NIL;
    1041              :     Relation    pgclass;
    1042              :     TableScanDesc scan;
    1043              :     HeapTuple   tuple;
    1044              : 
    1045          111 :     pgclass = table_open(RelationRelationId, AccessShareLock);
    1046              : 
    1047          111 :     scan = table_beginscan_catalog(pgclass, 0, NULL);
    1048              : 
    1049        50235 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    1050              :     {
    1051        50124 :         Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
    1052              :         MemoryContext oldcontext;
    1053        50124 :         Oid         relid = classForm->oid;
    1054              : 
    1055              :         /*
    1056              :          * We include partitioned tables here; depending on which operation is
    1057              :          * to be performed, caller will decide whether to process or ignore
    1058              :          * them.
    1059              :          */
    1060        50124 :         if (classForm->relkind != RELKIND_RELATION &&
    1061        40997 :             classForm->relkind != RELKIND_MATVIEW &&
    1062        40973 :             classForm->relkind != RELKIND_PARTITIONED_TABLE)
    1063        40891 :             continue;
    1064              : 
    1065              :         /* check permissions of relation */
    1066         9233 :         if (!vacuum_is_permitted_for_relation(relid, classForm, options))
    1067         1377 :             continue;
    1068              : 
    1069              :         /*
    1070              :          * Build VacuumRelation(s) specifying the table OIDs to be processed.
    1071              :          * We omit a RangeVar since it wouldn't be appropriate to complain
    1072              :          * about failure to open one of these relations later.
    1073              :          */
    1074         7856 :         oldcontext = MemoryContextSwitchTo(vac_context);
    1075         7856 :         vacrels = lappend(vacrels, makeVacuumRelation(NULL,
    1076              :                                                       relid,
    1077              :                                                       NIL));
    1078         7856 :         MemoryContextSwitchTo(oldcontext);
    1079              :     }
    1080              : 
    1081          111 :     table_endscan(scan);
    1082          111 :     table_close(pgclass, AccessShareLock);
    1083              : 
    1084          111 :     return vacrels;
    1085              : }
    1086              : 
    1087              : /*
    1088              :  * vacuum_get_cutoffs() -- compute OldestXmin and freeze cutoff points
    1089              :  *
    1090              :  * The target relation and VACUUM parameters are our inputs.
    1091              :  *
    1092              :  * Output parameters are the cutoffs that VACUUM caller should use.
    1093              :  *
    1094              :  * Return value indicates if vacuumlazy.c caller should make its VACUUM
    1095              :  * operation aggressive.  An aggressive VACUUM must advance relfrozenxid up to
    1096              :  * FreezeLimit (at a minimum), and relminmxid up to MultiXactCutoff (at a
    1097              :  * minimum).
    1098              :  */
    1099              : bool
    1100       116537 : vacuum_get_cutoffs(Relation rel, const VacuumParams params,
    1101              :                    struct VacuumCutoffs *cutoffs)
    1102              : {
    1103              :     int         freeze_min_age,
    1104              :                 multixact_freeze_min_age,
    1105              :                 freeze_table_age,
    1106              :                 multixact_freeze_table_age,
    1107              :                 effective_multixact_freeze_max_age;
    1108              :     TransactionId nextXID,
    1109              :                 safeOldestXmin,
    1110              :                 aggressiveXIDCutoff;
    1111              :     MultiXactId nextMXID,
    1112              :                 safeOldestMxact,
    1113              :                 aggressiveMXIDCutoff;
    1114              : 
    1115              :     /* Use mutable copies of freeze age parameters */
    1116       116537 :     freeze_min_age = params.freeze_min_age;
    1117       116537 :     multixact_freeze_min_age = params.multixact_freeze_min_age;
    1118       116537 :     freeze_table_age = params.freeze_table_age;
    1119       116537 :     multixact_freeze_table_age = params.multixact_freeze_table_age;
    1120              : 
    1121              :     /* Set pg_class fields in cutoffs */
    1122       116537 :     cutoffs->relfrozenxid = rel->rd_rel->relfrozenxid;
    1123       116537 :     cutoffs->relminmxid = rel->rd_rel->relminmxid;
    1124              : 
    1125              :     /*
    1126              :      * Acquire OldestXmin.
    1127              :      *
    1128              :      * We can always ignore processes running lazy vacuum.  This is because we
    1129              :      * use these values only for deciding which tuples we must keep in the
    1130              :      * tables.  Since lazy vacuum doesn't write its XID anywhere (usually no
    1131              :      * XID assigned), it's safe to ignore it.  In theory it could be
    1132              :      * problematic to ignore lazy vacuums in a full vacuum, but keep in mind
    1133              :      * that only one vacuum process can be working on a particular table at
    1134              :      * any time, and that each vacuum is always an independent transaction.
    1135              :      */
    1136       116537 :     cutoffs->OldestXmin = GetOldestNonRemovableTransactionId(rel);
    1137              : 
    1138              :     Assert(TransactionIdIsNormal(cutoffs->OldestXmin));
    1139              : 
    1140              :     /* Acquire OldestMxact */
    1141       116537 :     cutoffs->OldestMxact = GetOldestMultiXactId();
    1142              :     Assert(MultiXactIdIsValid(cutoffs->OldestMxact));
    1143              : 
    1144              :     /* Acquire next XID/next MXID values used to apply age-based settings */
    1145       116537 :     nextXID = ReadNextTransactionId();
    1146       116537 :     nextMXID = ReadNextMultiXactId();
    1147              : 
    1148              :     /*
    1149              :      * Also compute the multixact age for which freezing is urgent.  This is
    1150              :      * normally autovacuum_multixact_freeze_max_age, but may be less if
    1151              :      * multixact members are bloated.
    1152              :      */
    1153       116537 :     effective_multixact_freeze_max_age = MultiXactMemberFreezeThreshold();
    1154              : 
    1155              :     /*
    1156              :      * Almost ready to set freeze output parameters; check if OldestXmin or
    1157              :      * OldestMxact are held back to an unsafe degree before we start on that
    1158              :      */
    1159       116537 :     safeOldestXmin = nextXID - autovacuum_freeze_max_age;
    1160       116537 :     if (!TransactionIdIsNormal(safeOldestXmin))
    1161            0 :         safeOldestXmin = FirstNormalTransactionId;
    1162       116537 :     safeOldestMxact = nextMXID - effective_multixact_freeze_max_age;
    1163       116537 :     if (safeOldestMxact < FirstMultiXactId)
    1164            0 :         safeOldestMxact = FirstMultiXactId;
    1165       116537 :     if (TransactionIdPrecedes(cutoffs->OldestXmin, safeOldestXmin))
    1166        84976 :         ereport(WARNING,
    1167              :                 (errmsg("cutoff for removing and freezing tuples is far in the past"),
    1168              :                  errhint("Close open transactions soon to avoid wraparound problems.\n"
    1169              :                          "You might also need to commit or roll back old prepared transactions, or drop stale replication slots.")));
    1170       116537 :     if (MultiXactIdPrecedes(cutoffs->OldestMxact, safeOldestMxact))
    1171            0 :         ereport(WARNING,
    1172              :                 (errmsg("cutoff for freezing multixacts is far in the past"),
    1173              :                  errhint("Close open transactions soon to avoid wraparound problems.\n"
    1174              :                          "You might also need to commit or roll back old prepared transactions, or drop stale replication slots.")));
    1175              : 
    1176              :     /*
    1177              :      * Determine the minimum freeze age to use: as specified by the caller, or
    1178              :      * vacuum_freeze_min_age, but in any case not more than half
    1179              :      * autovacuum_freeze_max_age, so that autovacuums to prevent XID
    1180              :      * wraparound won't occur too frequently.
    1181              :      */
    1182       116537 :     if (freeze_min_age < 0)
    1183         5740 :         freeze_min_age = vacuum_freeze_min_age;
    1184       116537 :     freeze_min_age = Min(freeze_min_age, autovacuum_freeze_max_age / 2);
    1185              :     Assert(freeze_min_age >= 0);
    1186              : 
    1187              :     /* Compute FreezeLimit, being careful to generate a normal XID */
    1188       116537 :     cutoffs->FreezeLimit = nextXID - freeze_min_age;
    1189       116537 :     if (!TransactionIdIsNormal(cutoffs->FreezeLimit))
    1190            0 :         cutoffs->FreezeLimit = FirstNormalTransactionId;
    1191              :     /* FreezeLimit must always be <= OldestXmin */
    1192       116537 :     if (TransactionIdPrecedes(cutoffs->OldestXmin, cutoffs->FreezeLimit))
    1193        96679 :         cutoffs->FreezeLimit = cutoffs->OldestXmin;
    1194              : 
    1195              :     /*
    1196              :      * Determine the minimum multixact freeze age to use: as specified by
    1197              :      * caller, or vacuum_multixact_freeze_min_age, but in any case not more
    1198              :      * than half effective_multixact_freeze_max_age, so that autovacuums to
    1199              :      * prevent MultiXact wraparound won't occur too frequently.
    1200              :      */
    1201       116537 :     if (multixact_freeze_min_age < 0)
    1202         5740 :         multixact_freeze_min_age = vacuum_multixact_freeze_min_age;
    1203       116537 :     multixact_freeze_min_age = Min(multixact_freeze_min_age,
    1204              :                                    effective_multixact_freeze_max_age / 2);
    1205              :     Assert(multixact_freeze_min_age >= 0);
    1206              : 
    1207              :     /* Compute MultiXactCutoff, being careful to generate a valid value */
    1208       116537 :     cutoffs->MultiXactCutoff = nextMXID - multixact_freeze_min_age;
    1209       116537 :     if (cutoffs->MultiXactCutoff < FirstMultiXactId)
    1210            0 :         cutoffs->MultiXactCutoff = FirstMultiXactId;
    1211              :     /* MultiXactCutoff must always be <= OldestMxact */
    1212       116537 :     if (MultiXactIdPrecedes(cutoffs->OldestMxact, cutoffs->MultiXactCutoff))
    1213            2 :         cutoffs->MultiXactCutoff = cutoffs->OldestMxact;
    1214              : 
    1215              :     /*
    1216              :      * Finally, figure out if caller needs to do an aggressive VACUUM or not.
    1217              :      *
    1218              :      * Determine the table freeze age to use: as specified by the caller, or
    1219              :      * the value of the vacuum_freeze_table_age GUC, but in any case not more
    1220              :      * than autovacuum_freeze_max_age * 0.95, so that if you have e.g nightly
    1221              :      * VACUUM schedule, the nightly VACUUM gets a chance to freeze XIDs before
    1222              :      * anti-wraparound autovacuum is launched.
    1223              :      */
    1224       116537 :     if (freeze_table_age < 0)
    1225         5740 :         freeze_table_age = vacuum_freeze_table_age;
    1226       116537 :     freeze_table_age = Min(freeze_table_age, autovacuum_freeze_max_age * 0.95);
    1227              :     Assert(freeze_table_age >= 0);
    1228       116537 :     aggressiveXIDCutoff = nextXID - freeze_table_age;
    1229       116537 :     if (!TransactionIdIsNormal(aggressiveXIDCutoff))
    1230            0 :         aggressiveXIDCutoff = FirstNormalTransactionId;
    1231       116537 :     if (TransactionIdPrecedesOrEquals(cutoffs->relfrozenxid,
    1232              :                                       aggressiveXIDCutoff))
    1233       110788 :         return true;
    1234              : 
    1235              :     /*
    1236              :      * Similar to the above, determine the table freeze age to use for
    1237              :      * multixacts: as specified by the caller, or the value of the
    1238              :      * vacuum_multixact_freeze_table_age GUC, but in any case not more than
    1239              :      * effective_multixact_freeze_max_age * 0.95, so that if you have e.g.
    1240              :      * nightly VACUUM schedule, the nightly VACUUM gets a chance to freeze
    1241              :      * multixacts before anti-wraparound autovacuum is launched.
    1242              :      */
    1243         5749 :     if (multixact_freeze_table_age < 0)
    1244         5639 :         multixact_freeze_table_age = vacuum_multixact_freeze_table_age;
    1245         5749 :     multixact_freeze_table_age =
    1246         5749 :         Min(multixact_freeze_table_age,
    1247              :             effective_multixact_freeze_max_age * 0.95);
    1248              :     Assert(multixact_freeze_table_age >= 0);
    1249         5749 :     aggressiveMXIDCutoff = nextMXID - multixact_freeze_table_age;
    1250         5749 :     if (aggressiveMXIDCutoff < FirstMultiXactId)
    1251            0 :         aggressiveMXIDCutoff = FirstMultiXactId;
    1252         5749 :     if (MultiXactIdPrecedesOrEquals(cutoffs->relminmxid,
    1253              :                                     aggressiveMXIDCutoff))
    1254            0 :         return true;
    1255              : 
    1256              :     /* Non-aggressive VACUUM */
    1257         5749 :     return false;
    1258              : }
    1259              : 
    1260              : /*
    1261              :  * vacuum_xid_failsafe_check() -- Used by VACUUM's wraparound failsafe
    1262              :  * mechanism to determine if its table's relfrozenxid and relminmxid are now
    1263              :  * dangerously far in the past.
    1264              :  *
    1265              :  * When we return true, VACUUM caller triggers the failsafe.
    1266              :  */
    1267              : bool
    1268       118172 : vacuum_xid_failsafe_check(const struct VacuumCutoffs *cutoffs)
    1269              : {
    1270       118172 :     TransactionId relfrozenxid = cutoffs->relfrozenxid;
    1271       118172 :     MultiXactId relminmxid = cutoffs->relminmxid;
    1272              :     TransactionId xid_skip_limit;
    1273              :     MultiXactId multi_skip_limit;
    1274              :     int         skip_index_vacuum;
    1275              : 
    1276              :     Assert(TransactionIdIsNormal(relfrozenxid));
    1277              :     Assert(MultiXactIdIsValid(relminmxid));
    1278              : 
    1279              :     /*
    1280              :      * Determine the index skipping age to use. In any case no less than
    1281              :      * autovacuum_freeze_max_age * 1.05.
    1282              :      */
    1283       118172 :     skip_index_vacuum = Max(vacuum_failsafe_age, autovacuum_freeze_max_age * 1.05);
    1284              : 
    1285       118172 :     xid_skip_limit = ReadNextTransactionId() - skip_index_vacuum;
    1286       118172 :     if (!TransactionIdIsNormal(xid_skip_limit))
    1287            0 :         xid_skip_limit = FirstNormalTransactionId;
    1288              : 
    1289       118172 :     if (TransactionIdPrecedes(relfrozenxid, xid_skip_limit))
    1290              :     {
    1291              :         /* The table's relfrozenxid is too old */
    1292        21234 :         return true;
    1293              :     }
    1294              : 
    1295              :     /*
    1296              :      * Similar to above, determine the index skipping age to use for
    1297              :      * multixact. In any case no less than autovacuum_multixact_freeze_max_age *
    1298              :      * 1.05.
    1299              :      */
    1300        96938 :     skip_index_vacuum = Max(vacuum_multixact_failsafe_age,
    1301              :                             autovacuum_multixact_freeze_max_age * 1.05);
    1302              : 
    1303        96938 :     multi_skip_limit = ReadNextMultiXactId() - skip_index_vacuum;
    1304        96938 :     if (multi_skip_limit < FirstMultiXactId)
    1305            0 :         multi_skip_limit = FirstMultiXactId;
    1306              : 
    1307        96938 :     if (MultiXactIdPrecedes(relminmxid, multi_skip_limit))
    1308              :     {
    1309              :         /* The table's relminmxid is too old */
    1310            0 :         return true;
    1311              :     }
    1312              : 
    1313        96938 :     return false;
    1314              : }
    1315              : 
    1316              : /*
    1317              :  * vac_estimate_reltuples() -- estimate the new value for pg_class.reltuples
    1318              :  *
    1319              :  *      If we scanned the whole relation then we should just use the count of
    1320              :  *      live tuples seen; but if we did not, we should not blindly extrapolate
    1321              :  *      from that number, since VACUUM may have scanned a quite nonrandom
    1322              :  *      subset of the table.  When we have only partial information, we take
    1323              :  *      the old value of pg_class.reltuples/pg_class.relpages as a measurement
    1324              :  *      of the tuple density in the unscanned pages.
    1325              :  *
    1326              :  *      Note: scanned_tuples should count only *live* tuples, since
    1327              :  *      pg_class.reltuples is defined that way.
    1328              :  */
    1329              : double
    1330       116253 : vac_estimate_reltuples(Relation relation,
    1331              :                        BlockNumber total_pages,
    1332              :                        BlockNumber scanned_pages,
    1333              :                        double scanned_tuples)
    1334              : {
    1335       116253 :     BlockNumber old_rel_pages = relation->rd_rel->relpages;
    1336       116253 :     double      old_rel_tuples = relation->rd_rel->reltuples;
    1337              :     double      old_density;
    1338              :     double      unscanned_pages;
    1339              :     double      total_tuples;
    1340              : 
    1341              :     /* If we did scan the whole table, just use the count as-is */
    1342       116253 :     if (scanned_pages >= total_pages)
    1343       112107 :         return scanned_tuples;
    1344              : 
    1345              :     /*
    1346              :      * When successive VACUUM commands scan the same few pages again and
    1347              :      * again, without anything from the table really changing, there is a risk
    1348              :      * that our beliefs about tuple density will gradually become distorted.
    1349              :      * This might be caused by vacuumlazy.c implementation details, such as
    1350              :      * its tendency to always scan the last heap page.  Handle that here.
    1351              :      *
    1352              :      * If the relation is _exactly_ the same size according to the existing
    1353              :      * pg_class entry, and only a few of its pages (less than 2%) were
    1354              :      * scanned, keep the existing value of reltuples.  Also keep the existing
    1355              :      * value when only a subset of rel's pages <= a single page were scanned.
    1356              :      *
    1357              :      * (Note: we might be returning -1 here.)
    1358              :      */
    1359         4146 :     if (old_rel_pages == total_pages &&
    1360         4130 :         scanned_pages < (double) total_pages * 0.02)
    1361         2989 :         return old_rel_tuples;
    1362         1157 :     if (scanned_pages <= 1)
    1363         1024 :         return old_rel_tuples;
    1364              : 
    1365              :     /*
    1366              :      * If old density is unknown, we can't do much except scale up
    1367              :      * scanned_tuples to match total_pages.
    1368              :      */
    1369          133 :     if (old_rel_tuples < 0 || old_rel_pages == 0)
    1370            1 :         return floor((scanned_tuples / scanned_pages) * total_pages + 0.5);
    1371              : 
    1372              :     /*
    1373              :      * Okay, we've covered the corner cases.  The normal calculation is to
    1374              :      * convert the old measurement to a density (tuples per page), then
    1375              :      * estimate the number of tuples in the unscanned pages using that figure,
    1376              :      * and finally add on the number of tuples in the scanned pages.
    1377              :      */
    1378          132 :     old_density = old_rel_tuples / old_rel_pages;
    1379          132 :     unscanned_pages = (double) total_pages - (double) scanned_pages;
    1380          132 :     total_tuples = old_density * unscanned_pages + scanned_tuples;
    1381          132 :     return floor(total_tuples + 0.5);
    1382              : }
    1383              : 
    1384              : 
    1385              : /*
    1386              :  *  vac_update_relstats() -- update statistics for one relation
    1387              :  *
    1388              :  *      Update the whole-relation statistics that are kept in its pg_class
    1389              :  *      row.  There are additional stats that will be updated if we are
    1390              :  *      doing ANALYZE, but we always update these stats.  This routine works
    1391              :  *      for both index and heap relation entries in pg_class.
    1392              :  *
    1393              :  *      We violate transaction semantics here by overwriting the rel's
    1394              :  *      existing pg_class tuple with the new values.  This is reasonably
    1395              :  *      safe as long as we're sure that the new values are correct whether or
    1396              :  *      not this transaction commits.  The reason for doing this is that if
    1397              :  *      we updated these tuples in the usual way, vacuuming pg_class itself
    1398              :  *      wouldn't work very well --- by the time we got done with a vacuum
    1399              :  *      cycle, most of the tuples in pg_class would've been obsoleted.  Of
    1400              :  *      course, this only works for fixed-size not-null columns, but these are.
    1401              :  *
    1402              :  *      Another reason for doing it this way is that when we are in a lazy
    1403              :  *      VACUUM and have PROC_IN_VACUUM set, we mustn't do any regular updates.
    1404              :  *      Somebody vacuuming pg_class might think they could delete a tuple
    1405              :  *      marked with xmin = our xid.
    1406              :  *
    1407              :  *      In addition to fundamentally nontransactional statistics such as
    1408              :  *      relpages and relallvisible, we try to maintain certain lazily-updated
    1409              :  *      DDL flags such as relhasindex, by clearing them if no longer correct.
    1410              :  *      It's safe to do this in VACUUM, which can't run in parallel with
    1411              :  *      CREATE INDEX/RULE/TRIGGER and can't be part of a transaction block.
    1412              :  *      However, it's *not* safe to do it in an ANALYZE that's within an
    1413              :  *      outer transaction, because for example the current transaction might
    1414              :  *      have dropped the last index; then we'd think relhasindex should be
    1415              :  *      cleared, but if the transaction later rolls back this would be wrong.
    1416              :  *      So we refrain from updating the DDL flags if we're inside an outer
    1417              :  *      transaction.  This is OK since postponing the flag maintenance is
    1418              :  *      always allowable.
    1419              :  *
    1420              :  *      Note: num_tuples should count only *live* tuples, since
    1421              :  *      pg_class.reltuples is defined that way.
    1422              :  *
    1423              :  *      This routine is shared by VACUUM and ANALYZE.
    1424              :  */
    1425              : void
    1426       137887 : vac_update_relstats(Relation relation,
    1427              :                     BlockNumber num_pages, double num_tuples,
    1428              :                     BlockNumber num_all_visible_pages,
    1429              :                     BlockNumber num_all_frozen_pages,
    1430              :                     bool hasindex, TransactionId frozenxid,
    1431              :                     MultiXactId minmulti,
    1432              :                     bool *frozenxid_updated, bool *minmulti_updated,
    1433              :                     bool in_outer_xact)
    1434              : {
    1435       137887 :     Oid         relid = RelationGetRelid(relation);
    1436              :     Relation    rd;
    1437              :     ScanKeyData key[1];
    1438              :     HeapTuple   ctup;
    1439              :     void       *inplace_state;
    1440              :     Form_pg_class pgcform;
    1441              :     bool        dirty,
    1442              :                 futurexid,
    1443              :                 futuremxid;
    1444              :     TransactionId oldfrozenxid;
    1445              :     MultiXactId oldminmulti;
    1446              : 
    1447       137887 :     rd = table_open(RelationRelationId, RowExclusiveLock);
    1448              : 
    1449              :     /* Fetch a copy of the tuple to scribble on */
    1450       137887 :     ScanKeyInit(&key[0],
    1451              :                 Anum_pg_class_oid,
    1452              :                 BTEqualStrategyNumber, F_OIDEQ,
    1453              :                 ObjectIdGetDatum(relid));
    1454       137887 :     systable_inplace_update_begin(rd, ClassOidIndexId, true,
    1455              :                                   NULL, 1, key, &ctup, &inplace_state);
    1456       137887 :     if (!HeapTupleIsValid(ctup))
    1457            0 :         elog(ERROR, "pg_class entry for relid %u vanished during vacuuming",
    1458              :              relid);
    1459       137887 :     pgcform = (Form_pg_class) GETSTRUCT(ctup);
    1460              : 
    1461              :     /* Apply statistical updates, if any, to copied tuple */
    1462              : 
    1463       137887 :     dirty = false;
    1464       137887 :     if (pgcform->relpages != (int32) num_pages)
    1465              :     {
    1466         4889 :         pgcform->relpages = (int32) num_pages;
    1467         4889 :         dirty = true;
    1468              :     }
    1469       137887 :     if (pgcform->reltuples != (float4) num_tuples)
    1470              :     {
    1471        10438 :         pgcform->reltuples = (float4) num_tuples;
    1472        10438 :         dirty = true;
    1473              :     }
    1474       137887 :     if (pgcform->relallvisible != (int32) num_all_visible_pages)
    1475              :     {
    1476         2977 :         pgcform->relallvisible = (int32) num_all_visible_pages;
    1477         2977 :         dirty = true;
    1478              :     }
    1479       137887 :     if (pgcform->relallfrozen != (int32) num_all_frozen_pages)
    1480              :     {
    1481         2693 :         pgcform->relallfrozen = (int32) num_all_frozen_pages;
    1482         2693 :         dirty = true;
    1483              :     }
    1484              : 
    1485              :     /* Apply DDL updates, but not inside an outer transaction (see above) */
    1486              : 
    1487       137887 :     if (!in_outer_xact)
    1488              :     {
    1489              :         /*
    1490              :          * If we didn't find any indexes, reset relhasindex.
    1491              :          */
    1492       137700 :         if (pgcform->relhasindex && !hasindex)
    1493              :         {
    1494           11 :             pgcform->relhasindex = false;
    1495           11 :             dirty = true;
    1496              :         }
    1497              : 
    1498              :         /* We also clear relhasrules and relhastriggers if needed */
    1499       137700 :         if (pgcform->relhasrules && relation->rd_rules == NULL)
    1500              :         {
    1501            0 :             pgcform->relhasrules = false;
    1502            0 :             dirty = true;
    1503              :         }
    1504       137700 :         if (pgcform->relhastriggers && relation->trigdesc == NULL)
    1505              :         {
    1506            3 :             pgcform->relhastriggers = false;
    1507            3 :             dirty = true;
    1508              :         }
    1509              :     }
    1510              : 
    1511              :     /*
    1512              :      * Update relfrozenxid, unless caller passed InvalidTransactionId
    1513              :      * indicating it has no new data.
    1514              :      *
    1515              :      * Ordinarily, we don't let relfrozenxid go backwards.  However, if the
    1516              :      * stored relfrozenxid is "in the future" then it seems best to assume
    1517              :      * it's corrupt, and overwrite with the oldest remaining XID in the table.
    1518              :      * This should match vac_update_datfrozenxid() concerning what we consider
    1519              :      * to be "in the future".
    1520              :      */
    1521       137887 :     oldfrozenxid = pgcform->relfrozenxid;
    1522       137887 :     futurexid = false;
    1523       137887 :     if (frozenxid_updated)
    1524       116251 :         *frozenxid_updated = false;
    1525       137887 :     if (TransactionIdIsNormal(frozenxid) && oldfrozenxid != frozenxid)
    1526              :     {
    1527        30046 :         bool        update = false;
    1528              : 
    1529        30046 :         if (TransactionIdPrecedes(oldfrozenxid, frozenxid))
    1530        29986 :             update = true;
    1531           60 :         else if (TransactionIdPrecedes(ReadNextTransactionId(), oldfrozenxid))
    1532            0 :             futurexid = update = true;
    1533              : 
    1534        30046 :         if (update)
    1535              :         {
    1536        29986 :             pgcform->relfrozenxid = frozenxid;
    1537        29986 :             dirty = true;
    1538        29986 :             if (frozenxid_updated)
    1539        29986 :                 *frozenxid_updated = true;
    1540              :         }
    1541              :     }
    1542              : 
    1543              :     /* Similarly for relminmxid */
    1544       137887 :     oldminmulti = pgcform->relminmxid;
    1545       137887 :     futuremxid = false;
    1546       137887 :     if (minmulti_updated)
    1547       116251 :         *minmulti_updated = false;
    1548       137887 :     if (MultiXactIdIsValid(minmulti) && oldminmulti != minmulti)
    1549              :     {
    1550          187 :         bool        update = false;
    1551              : 
    1552          187 :         if (MultiXactIdPrecedes(oldminmulti, minmulti))
    1553          187 :             update = true;
    1554            0 :         else if (MultiXactIdPrecedes(ReadNextMultiXactId(), oldminmulti))
    1555            0 :             futuremxid = update = true;
    1556              : 
    1557          187 :         if (update)
    1558              :         {
    1559          187 :             pgcform->relminmxid = minmulti;
    1560          187 :             dirty = true;
    1561          187 :             if (minmulti_updated)
    1562          187 :                 *minmulti_updated = true;
    1563              :         }
    1564              :     }
    1565              : 
    1566              :     /* If anything changed, write out the tuple. */
    1567       137887 :     if (dirty)
    1568        37410 :         systable_inplace_update_finish(inplace_state, ctup);
    1569              :     else
    1570       100477 :         systable_inplace_update_cancel(inplace_state);
    1571              : 
    1572       137887 :     table_close(rd, RowExclusiveLock);
    1573              : 
    1574       137887 :     if (futurexid)
    1575            0 :         ereport(WARNING,
    1576              :                 (errcode(ERRCODE_DATA_CORRUPTED),
    1577              :                  errmsg_internal("overwrote invalid relfrozenxid value %u with new value %u for table \"%s\"",
    1578              :                                  oldfrozenxid, frozenxid,
    1579              :                                  RelationGetRelationName(relation))));
    1580       137887 :     if (futuremxid)
    1581            0 :         ereport(WARNING,
    1582              :                 (errcode(ERRCODE_DATA_CORRUPTED),
    1583              :                  errmsg_internal("overwrote invalid relminmxid value %u with new value %u for table \"%s\"",
    1584              :                                  oldminmulti, minmulti,
    1585              :                                  RelationGetRelationName(relation))));
    1586       137887 : }
    1587              : 
    1588              : 
    1589              : /*
    1590              :  *  vac_update_datfrozenxid() -- update pg_database.datfrozenxid for our DB
    1591              :  *
    1592              :  *      Update pg_database's datfrozenxid entry for our database to be the
    1593              :  *      minimum of the pg_class.relfrozenxid values.
    1594              :  *
    1595              :  *      Similarly, update our datminmxid to be the minimum of the
    1596              :  *      pg_class.relminmxid values.
    1597              :  *
    1598              :  *      If we are able to advance either pg_database value, also try to
    1599              :  *      truncate pg_xact and pg_multixact.
    1600              :  *
    1601              :  *      We violate transaction semantics here by overwriting the database's
    1602              :  *      existing pg_database tuple with the new values.  This is reasonably
    1603              :  *      safe since the new values are correct whether or not this transaction
    1604              :  *      commits.  As with vac_update_relstats, this avoids leaving dead tuples
    1605              :  *      behind after a VACUUM.
    1606              :  */
    1607              : void
    1608         2640 : vac_update_datfrozenxid(void)
    1609              : {
    1610              :     HeapTuple   tuple;
    1611              :     Form_pg_database dbform;
    1612              :     Relation    relation;
    1613              :     SysScanDesc scan;
    1614              :     HeapTuple   classTup;
    1615              :     TransactionId newFrozenXid;
    1616              :     MultiXactId newMinMulti;
    1617              :     TransactionId lastSaneFrozenXid;
    1618              :     MultiXactId lastSaneMinMulti;
    1619         2640 :     bool        bogus = false;
    1620         2640 :     bool        dirty = false;
    1621              :     ScanKeyData key[1];
    1622              :     void       *inplace_state;
    1623              : 
    1624              :     /*
    1625              :      * Restrict this task to one backend per database.  This avoids race
    1626              :      * conditions that would move datfrozenxid or datminmxid backward.  It
    1627              :      * avoids calling vac_truncate_clog() with a datfrozenxid preceding a
    1628              :      * datfrozenxid passed to an earlier vac_truncate_clog() call.
    1629              :      */
    1630         2640 :     LockDatabaseFrozenIds(ExclusiveLock);
    1631              : 
    1632              :     /*
    1633              :      * Initialize the "min" calculation with
    1634              :      * GetOldestNonRemovableTransactionId(), which is a reasonable
    1635              :      * approximation to the minimum relfrozenxid for not-yet-committed
    1636              :      * pg_class entries for new tables; see AddNewRelationTuple().  So we
    1637              :      * cannot produce a wrong minimum by starting with this.
    1638              :      */
    1639         2640 :     newFrozenXid = GetOldestNonRemovableTransactionId(NULL);
    1640              : 
    1641              :     /*
    1642              :      * Similarly, initialize the MultiXact "min" with the value that would be
    1643              :      * used on pg_class for new tables.  See AddNewRelationTuple().
    1644              :      */
    1645         2640 :     newMinMulti = GetOldestMultiXactId();
    1646              : 
    1647              :     /*
    1648              :      * Identify the latest relfrozenxid and relminmxid values that we could
    1649              :      * validly see during the scan.  These are conservative values, but it's
    1650              :      * not really worth trying to be more exact.
    1651              :      */
    1652         2640 :     lastSaneFrozenXid = ReadNextTransactionId();
    1653         2640 :     lastSaneMinMulti = ReadNextMultiXactId();
    1654              : 
    1655              :     /*
    1656              :      * We must seqscan pg_class to find the minimum Xid, because there is no
    1657              :      * index that can help us here.
    1658              :      *
    1659              :      * See vac_truncate_clog() for the race condition to prevent.
    1660              :      */
    1661         2640 :     relation = table_open(RelationRelationId, AccessShareLock);
    1662              : 
    1663         2640 :     scan = systable_beginscan(relation, InvalidOid, false,
    1664              :                               NULL, 0, NULL);
    1665              : 
    1666      1333750 :     while ((classTup = systable_getnext(scan)) != NULL)
    1667              :     {
    1668      1331110 :         volatile FormData_pg_class *classForm = (Form_pg_class) GETSTRUCT(classTup);
    1669      1331110 :         TransactionId relfrozenxid = classForm->relfrozenxid;
    1670      1331110 :         TransactionId relminmxid = classForm->relminmxid;
    1671              : 
    1672              :         /*
    1673              :          * Only consider relations able to hold unfrozen XIDs (anything else
    1674              :          * should have InvalidTransactionId in relfrozenxid anyway).
    1675              :          */
    1676      1331110 :         if (classForm->relkind != RELKIND_RELATION &&
    1677      1060076 :             classForm->relkind != RELKIND_MATVIEW &&
    1678      1058861 :             classForm->relkind != RELKIND_TOASTVALUE)
    1679              :         {
    1680              :             Assert(!TransactionIdIsValid(relfrozenxid));
    1681              :             Assert(!MultiXactIdIsValid(relminmxid));
    1682       918583 :             continue;
    1683              :         }
    1684              : 
    1685              :         /*
    1686              :          * Some table AMs might not need per-relation xid / multixid horizons.
    1687              :          * It therefore seems reasonable to allow relfrozenxid and relminmxid
    1688              :          * to not be set (i.e. set to their respective Invalid*Id)
    1689              :          * independently. Thus validate and compute horizon for each only if
    1690              :          * set.
    1691              :          *
    1692              :          * If things are working properly, no relation should have a
    1693              :          * relfrozenxid or relminmxid that is "in the future".  However, such
    1694              :          * cases have been known to arise due to bugs in pg_upgrade.  If we
    1695              :          * see any entries that are "in the future", chicken out and don't do
    1696              :          * anything.  This ensures we won't truncate clog & multixact SLRUs
    1697              :          * before those relations have been scanned and cleaned up.
    1698              :          */
    1699              : 
    1700       412527 :         if (TransactionIdIsValid(relfrozenxid))
    1701              :         {
    1702              :             Assert(TransactionIdIsNormal(relfrozenxid));
    1703              : 
    1704              :             /* check for values in the future */
    1705       412527 :             if (TransactionIdPrecedes(lastSaneFrozenXid, relfrozenxid))
    1706              :             {
    1707            0 :                 bogus = true;
    1708            0 :                 break;
    1709              :             }
    1710              : 
    1711              :             /* determine new horizon */
    1712       412527 :             if (TransactionIdPrecedes(relfrozenxid, newFrozenXid))
    1713         2425 :                 newFrozenXid = relfrozenxid;
    1714              :         }
    1715              : 
    1716       412527 :         if (MultiXactIdIsValid(relminmxid))
    1717              :         {
    1718              :             /* check for values in the future */
    1719       412527 :             if (MultiXactIdPrecedes(lastSaneMinMulti, relminmxid))
    1720              :             {
    1721            0 :                 bogus = true;
    1722            0 :                 break;
    1723              :             }
    1724              : 
    1725              :             /* determine new horizon */
    1726       412527 :             if (MultiXactIdPrecedes(relminmxid, newMinMulti))
    1727          114 :                 newMinMulti = relminmxid;
    1728              :         }
    1729              :     }
    1730              : 
    1731              :     /* we're done with pg_class */
    1732         2640 :     systable_endscan(scan);
    1733         2640 :     table_close(relation, AccessShareLock);
    1734              : 
    1735              :     /* chicken out if bogus data found */
    1736         2640 :     if (bogus)
    1737            0 :         return;
    1738              : 
    1739              :     Assert(TransactionIdIsNormal(newFrozenXid));
    1740              :     Assert(MultiXactIdIsValid(newMinMulti));
    1741              : 
    1742              :     /* Now fetch the pg_database tuple we need to update. */
    1743         2640 :     relation = table_open(DatabaseRelationId, RowExclusiveLock);
    1744              : 
    1745              :     /*
    1746              :      * Fetch a copy of the tuple to scribble on.  We could check the syscache
    1747              :      * tuple first.  If that concluded !dirty, we'd avoid waiting on
    1748              :      * concurrent heap_update() and would avoid exclusive-locking the buffer.
    1749              :      * For now, don't optimize that.
    1750              :      */
    1751         2640 :     ScanKeyInit(&key[0],
    1752              :                 Anum_pg_database_oid,
    1753              :                 BTEqualStrategyNumber, F_OIDEQ,
    1754              :                 ObjectIdGetDatum(MyDatabaseId));
    1755              : 
    1756         2640 :     systable_inplace_update_begin(relation, DatabaseOidIndexId, true,
    1757              :                                   NULL, 1, key, &tuple, &inplace_state);
    1758              : 
    1759         2640 :     if (!HeapTupleIsValid(tuple))
    1760            0 :         elog(ERROR, "could not find tuple for database %u", MyDatabaseId);
    1761              : 
    1762         2640 :     dbform = (Form_pg_database) GETSTRUCT(tuple);
    1763              : 
    1764              :     /*
    1765              :      * As in vac_update_relstats(), we ordinarily don't want to let
    1766              :      * datfrozenxid go backward; but if it's "in the future" then it must be
    1767              :      * corrupt and it seems best to overwrite it.
    1768              :      */
    1769         2966 :     if (dbform->datfrozenxid != newFrozenXid &&
    1770          326 :         (TransactionIdPrecedes(dbform->datfrozenxid, newFrozenXid) ||
    1771            0 :          TransactionIdPrecedes(lastSaneFrozenXid, dbform->datfrozenxid)))
    1772              :     {
    1773          326 :         dbform->datfrozenxid = newFrozenXid;
    1774          326 :         dirty = true;
    1775              :     }
    1776              :     else
    1777         2314 :         newFrozenXid = dbform->datfrozenxid;
    1778              : 
    1779              :     /* Ditto for datminmxid */
    1780         2641 :     if (dbform->datminmxid != newMinMulti &&
    1781            1 :         (MultiXactIdPrecedes(dbform->datminmxid, newMinMulti) ||
    1782            0 :          MultiXactIdPrecedes(lastSaneMinMulti, dbform->datminmxid)))
    1783              :     {
    1784            1 :         dbform->datminmxid = newMinMulti;
    1785            1 :         dirty = true;
    1786              :     }
    1787              :     else
    1788         2639 :         newMinMulti = dbform->datminmxid;
    1789              : 
    1790         2640 :     if (dirty)
    1791          326 :         systable_inplace_update_finish(inplace_state, tuple);
    1792              :     else
    1793         2314 :         systable_inplace_update_cancel(inplace_state);
    1794              : 
    1795         2640 :     heap_freetuple(tuple);
    1796         2640 :     table_close(relation, RowExclusiveLock);
    1797              : 
    1798              :     /*
    1799              :      * If we were able to advance datfrozenxid or datminmxid, see if we can
    1800              :      * truncate pg_xact and/or pg_multixact.  Also do it if the shared
    1801              :      * XID-wrap-limit info is stale, since this action will update that too.
    1802              :      */
    1803         2640 :     if (dirty || ForceTransactionIdLimitUpdate())
    1804         1130 :         vac_truncate_clog(newFrozenXid, newMinMulti,
    1805              :                           lastSaneFrozenXid, lastSaneMinMulti);
    1806              : }
    1807              : 
    1808              : 
    1809              : /*
    1810              :  *  vac_truncate_clog() -- attempt to truncate the commit log
    1811              :  *
    1812              :  *      Scan pg_database to determine the system-wide oldest datfrozenxid,
    1813              :  *      and use it to truncate the transaction commit log (pg_xact).
    1814              :  *      Also update the XID wrap limit info maintained by varsup.c.
    1815              :  *      Likewise for datminmxid.
    1816              :  *
    1817              :  *      The passed frozenXID and minMulti are the updated values for my own
    1818              :  *      pg_database entry. They're used to initialize the "min" calculations.
    1819              :  *      The caller also passes the "last sane" XID and MXID, since it has
    1820              :  *      those at hand already.
    1821              :  *
    1822              :  *      This routine is only invoked when we've managed to change our
    1823              :  *      DB's datfrozenxid/datminmxid values, or we found that the shared
    1824              :  *      XID-wrap-limit info is stale.
    1825              :  */
    1826              : static void
    1827         1130 : vac_truncate_clog(TransactionId frozenXID,
    1828              :                   MultiXactId minMulti,
    1829              :                   TransactionId lastSaneFrozenXid,
    1830              :                   MultiXactId lastSaneMinMulti)
    1831              : {
    1832         1130 :     TransactionId nextXID = ReadNextTransactionId();
    1833              :     Relation    relation;
    1834              :     TableScanDesc scan;
    1835              :     HeapTuple   tuple;
    1836              :     Oid         oldestxid_datoid;
    1837              :     Oid         minmulti_datoid;
    1838         1130 :     bool        bogus = false;
    1839         1130 :     bool        frozenAlreadyWrapped = false;
    1840              : 
    1841              :     /* Restrict task to one backend per cluster; see SimpleLruTruncate(). */
    1842         1130 :     LWLockAcquire(WrapLimitsVacuumLock, LW_EXCLUSIVE);
    1843              : 
    1844              :     /* init oldest datoids to sync with my frozenXID/minMulti values */
    1845         1130 :     oldestxid_datoid = MyDatabaseId;
    1846         1130 :     minmulti_datoid = MyDatabaseId;
    1847              : 
    1848              :     /*
    1849              :      * Scan pg_database to compute the minimum datfrozenxid/datminmxid
    1850              :      *
    1851              :      * Since vac_update_datfrozenxid updates datfrozenxid/datminmxid in-place,
    1852              :      * the values could change while we look at them.  Fetch each one just
    1853              :      * once to ensure sane behavior of the comparison logic.  (Here, as in
    1854              :      * many other places, we assume that fetching or updating an XID in shared
    1855              :      * storage is atomic.)
    1856              :      *
    1857              :      * Note: we need not worry about a race condition with new entries being
    1858              :      * inserted by CREATE DATABASE.  Any such entry will have a copy of some
    1859              :      * existing DB's datfrozenxid, and that source DB cannot be ours because
    1860              :      * of the interlock against copying a DB containing an active backend.
    1861              :      * Hence the new entry will not reduce the minimum.  Also, if two VACUUMs
    1862              :      * concurrently modify the datfrozenxid's of different databases, the
    1863              :      * worst possible outcome is that pg_xact is not truncated as aggressively
    1864              :      * as it could be.
    1865              :      */
    1866         1130 :     relation = table_open(DatabaseRelationId, AccessShareLock);
    1867              : 
    1868         1130 :     scan = table_beginscan_catalog(relation, 0, NULL);
    1869              : 
    1870         4431 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    1871              :     {
    1872         3301 :         volatile FormData_pg_database *dbform = (Form_pg_database) GETSTRUCT(tuple);
    1873         3301 :         TransactionId datfrozenxid = dbform->datfrozenxid;
    1874         3301 :         TransactionId datminmxid = dbform->datminmxid;
    1875              : 
    1876              :         Assert(TransactionIdIsNormal(datfrozenxid));
    1877              :         Assert(MultiXactIdIsValid(datminmxid));
    1878              : 
    1879              :         /*
    1880              :          * If database is in the process of getting dropped, or has been
    1881              :          * interrupted while doing so, no connections to it are possible
    1882              :          * anymore. Therefore we don't need to take it into account here.
    1883              :          * Which is good, because it can't be processed by autovacuum either.
    1884              :          */
    1885         3301 :         if (database_is_invalid_form((Form_pg_database) dbform))
    1886              :         {
    1887            1 :             elog(DEBUG2,
    1888              :                  "skipping invalid database \"%s\" while computing relfrozenxid",
    1889              :                  NameStr(dbform->datname));
    1890            1 :             continue;
    1891              :         }
    1892              : 
    1893              :         /*
    1894              :          * If things are working properly, no database should have a
    1895              :          * datfrozenxid or datminmxid that is "in the future".  However, such
    1896              :          * cases have been known to arise due to bugs in pg_upgrade.  If we
    1897              :          * see any entries that are "in the future", chicken out and don't do
    1898              :          * anything.  This ensures we won't truncate clog before those
    1899              :          * databases have been scanned and cleaned up.  (We will issue the
    1900              :          * "already wrapped" warning if appropriate, though.)
    1901              :          */
    1902         6600 :         if (TransactionIdPrecedes(lastSaneFrozenXid, datfrozenxid) ||
    1903         3300 :             MultiXactIdPrecedes(lastSaneMinMulti, datminmxid))
    1904            0 :             bogus = true;
    1905              : 
    1906         3300 :         if (TransactionIdPrecedes(nextXID, datfrozenxid))
    1907            0 :             frozenAlreadyWrapped = true;
    1908         3300 :         else if (TransactionIdPrecedes(datfrozenxid, frozenXID))
    1909              :         {
    1910          235 :             frozenXID = datfrozenxid;
    1911          235 :             oldestxid_datoid = dbform->oid;
    1912              :         }
    1913              : 
    1914         3300 :         if (MultiXactIdPrecedes(datminmxid, minMulti))
    1915              :         {
    1916            2 :             minMulti = datminmxid;
    1917            2 :             minmulti_datoid = dbform->oid;
    1918              :         }
    1919              :     }
    1920              : 
    1921         1130 :     table_endscan(scan);
    1922              : 
    1923         1130 :     table_close(relation, AccessShareLock);
    1924              : 
    1925              :     /*
    1926              :      * Do not truncate CLOG if we seem to have suffered wraparound already;
    1927              :      * the computed minimum XID might be bogus.  This case should now be
    1928              :      * impossible due to the defenses in GetNewTransactionId, but we keep the
    1929              :      * test anyway.
    1930              :      */
    1931         1130 :     if (frozenAlreadyWrapped)
    1932              :     {
    1933            0 :         ereport(WARNING,
    1934              :                 (errmsg("some databases have not been vacuumed in over 2 billion transactions"),
    1935              :                  errdetail("You might have already suffered transaction-wraparound data loss.")));
    1936            0 :         LWLockRelease(WrapLimitsVacuumLock);
    1937            0 :         return;
    1938              :     }
    1939              : 
    1940              :     /* chicken out if data is bogus in any other way */
    1941         1130 :     if (bogus)
    1942              :     {
    1943            0 :         LWLockRelease(WrapLimitsVacuumLock);
    1944            0 :         return;
    1945              :     }
    1946              : 
    1947              :     /*
    1948              :      * Freeze any old transaction IDs in the async notification queue before
    1949              :      * CLOG truncation.
    1950              :      */
    1951         1130 :     AsyncNotifyFreezeXids(frozenXID);
    1952              : 
    1953              :     /*
    1954              :      * Advance the oldest value for commit timestamps before truncating, so
    1955              :      * that if a user requests a timestamp for a transaction we're truncating
    1956              :      * away right after this point, they get NULL instead of an ugly "file not
    1957              :      * found" error from slru.c.  This doesn't matter for xact/multixact
    1958              :      * because they are not subject to arbitrary lookups from users.
    1959              :      */
    1960         1130 :     AdvanceOldestCommitTsXid(frozenXID);
    1961              : 
    1962              :     /*
    1963              :      * Truncate CLOG, multixact and CommitTs to the oldest computed value.
    1964              :      */
    1965         1130 :     TruncateCLOG(frozenXID, oldestxid_datoid);
    1966         1130 :     TruncateCommitTs(frozenXID);
    1967         1130 :     TruncateMultiXact(minMulti, minmulti_datoid);
    1968              : 
    1969              :     /*
    1970              :      * Update the wrap limit for GetNewTransactionId and creation of new
    1971              :      * MultiXactIds.  Note: these functions will also signal the postmaster
    1972              :      * for an(other) autovac cycle if needed.   XXX should we avoid possibly
    1973              :      * signaling twice?
    1974              :      */
    1975         1130 :     SetTransactionIdLimit(frozenXID, oldestxid_datoid);
    1976         1130 :     SetMultiXactIdLimit(minMulti, minmulti_datoid);
    1977              : 
    1978         1130 :     LWLockRelease(WrapLimitsVacuumLock);
    1979              : }
    1980              : 
    1981              : 
    1982              : /*
    1983              :  *  vacuum_rel() -- vacuum one heap relation
    1984              :  *
    1985              :  *      relid identifies the relation to vacuum.  If relation is supplied,
    1986              :  *      use the name therein for reporting any failure to open/lock the rel;
    1987              :  *      do not use it once we've successfully opened the rel, since it might
    1988              :  *      be stale.
    1989              :  *
    1990              :  *      Returns true if it's okay to proceed with a requested ANALYZE
    1991              :  *      operation on this table.
    1992              :  *
    1993              :  *      Doing one heap at a time incurs extra overhead, since we need to
    1994              :  *      check that the heap exists again just before we vacuum it.  The
    1995              :  *      reason that we do this is so that vacuuming can be spread across
    1996              :  *      many small transactions.  Otherwise, two-phase locking would require
    1997              :  *      us to lock the entire database during one pass of the vacuum cleaner.
    1998              :  *
    1999              :  *      At entry and exit, we are not inside a transaction.
    2000              :  */
    2001              : static bool
    2002       116661 : vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
    2003              :            BufferAccessStrategy bstrategy)
    2004              : {
    2005              :     LOCKMODE    lmode;
    2006              :     Relation    rel;
    2007              :     LockRelId   lockrelid;
    2008              :     Oid         priv_relid;
    2009              :     Oid         toast_relid;
    2010              :     Oid         save_userid;
    2011              :     int         save_sec_context;
    2012              :     int         save_nestlevel;
    2013              :     VacuumParams toast_vacuum_params;
    2014              : 
    2015              :     /*
    2016              :      * This function scribbles on the parameters, so make a copy early to
    2017              :      * avoid affecting the TOAST table (if we do end up recursing to it).
    2018              :      */
    2019       116661 :     memcpy(&toast_vacuum_params, &params, sizeof(VacuumParams));
    2020              : 
    2021              :     /* Begin a transaction for vacuuming this relation */
    2022       116661 :     StartTransactionCommand();
    2023              : 
    2024       116661 :     if (!(params.options & VACOPT_FULL))
    2025              :     {
    2026              :         /*
    2027              :          * In lazy vacuum, we can set the PROC_IN_VACUUM flag, which lets
    2028              :          * other concurrent VACUUMs know that they can ignore this one while
    2029              :          * determining their OldestXmin.  (The reason we don't set it during a
    2030              :          * full VACUUM is exactly that we may have to run user-defined
    2031              :          * functions for functional indexes, and we want to make sure that if
    2032              :          * they use the snapshot set above, any tuples it requires can't get
    2033              :          * removed from other tables.  An index function that depends on the
    2034              :          * contents of other tables is arguably broken, but we won't break it
    2035              :          * here by violating transaction semantics.)
    2036              :          *
    2037              :          * We also set the VACUUM_FOR_WRAPAROUND flag, which is passed down by
    2038              :          * autovacuum; it's used to avoid canceling a vacuum that was invoked
    2039              :          * in an emergency.
    2040              :          *
    2041              :          * Note: these flags remain set until CommitTransaction or
    2042              :          * AbortTransaction.  We don't want to clear them until we reset
    2043              :          * MyProc->xid/xmin, otherwise GetOldestNonRemovableTransactionId()
    2044              :          * might appear to go backwards, which is probably Not Good.  (We also
    2045              :          * set PROC_IN_VACUUM *before* taking our own snapshot, so that our
    2046              :          * xmin doesn't become visible ahead of setting the flag.)
    2047              :          */
    2048       116454 :         LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
    2049       116454 :         MyProc->statusFlags |= PROC_IN_VACUUM;
    2050       116454 :         if (params.is_wraparound)
    2051       102247 :             MyProc->statusFlags |= PROC_VACUUM_FOR_WRAPAROUND;
    2052       116454 :         ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags;
    2053       116454 :         LWLockRelease(ProcArrayLock);
    2054              :     }
    2055              : 
    2056              :     /*
    2057              :      * Need to acquire a snapshot to prevent pg_subtrans from being truncated,
    2058              :      * cutoff xids in local memory wrapping around, and to have updated xmin
    2059              :      * horizons.
    2060              :      */
    2061       116661 :     PushActiveSnapshot(GetTransactionSnapshot());
    2062              : 
    2063              :     /*
    2064              :      * Check for user-requested abort.  Note we want this to be inside a
    2065              :      * transaction, so xact.c doesn't issue useless WARNING.
    2066              :      */
    2067       116661 :     CHECK_FOR_INTERRUPTS();
    2068              : 
    2069              :     /*
    2070              :      * Determine the type of lock we want --- hard exclusive lock for a FULL
    2071              :      * vacuum, but just ShareUpdateExclusiveLock for concurrent vacuum. Either
    2072              :      * way, we can be sure that no other backend is vacuuming the same table.
    2073              :      */
    2074       233322 :     lmode = (params.options & VACOPT_FULL) ?
    2075       116661 :         AccessExclusiveLock : ShareUpdateExclusiveLock;
    2076              : 
    2077              :     /* open the relation and get the appropriate lock on it */
    2078       116661 :     rel = vacuum_open_relation(relid, relation, params.options,
    2079       116661 :                                params.log_vacuum_min_duration >= 0, lmode);
    2080              : 
    2081              :     /* leave if relation could not be opened or locked */
    2082       116661 :     if (!rel)
    2083              :     {
    2084           12 :         PopActiveSnapshot();
    2085           12 :         CommitTransactionCommand();
    2086           12 :         return false;
    2087              :     }
    2088              : 
    2089              :     /*
    2090              :      * When recursing to a TOAST table, check privileges on the parent.  NB:
    2091              :      * This is only safe to do because we hold a session lock on the main
    2092              :      * relation that prevents concurrent deletion.
    2093              :      */
    2094       116649 :     if (OidIsValid(params.toast_parent))
    2095         4901 :         priv_relid = params.toast_parent;
    2096              :     else
    2097       111748 :         priv_relid = RelationGetRelid(rel);
    2098              : 
    2099              :     /*
    2100              :      * Check if relation needs to be skipped based on privileges.  This check
    2101              :      * happens also when building the relation list to vacuum for a manual
    2102              :      * operation, and needs to be done additionally here as VACUUM could
    2103              :      * happen across multiple transactions where privileges could have changed
    2104              :      * in-between.  Make sure to only generate logs for VACUUM in this case.
    2105              :      */
    2106       116649 :     if (!vacuum_is_permitted_for_relation(priv_relid,
    2107              :                                           rel->rd_rel,
    2108       116649 :                                           params.options & ~VACOPT_ANALYZE))
    2109              :     {
    2110           36 :         relation_close(rel, lmode);
    2111           36 :         PopActiveSnapshot();
    2112           36 :         CommitTransactionCommand();
    2113           36 :         return false;
    2114              :     }
    2115              : 
    2116              :     /*
    2117              :      * Check that it's of a vacuumable relkind.
    2118              :      */
    2119       116613 :     if (rel->rd_rel->relkind != RELKIND_RELATION &&
    2120        42466 :         rel->rd_rel->relkind != RELKIND_MATVIEW &&
    2121        42462 :         rel->rd_rel->relkind != RELKIND_TOASTVALUE &&
    2122           94 :         rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
    2123              :     {
    2124            1 :         ereport(WARNING,
    2125              :                 (errmsg("skipping \"%s\" --- cannot vacuum non-tables or special system tables",
    2126              :                         RelationGetRelationName(rel))));
    2127            1 :         relation_close(rel, lmode);
    2128            1 :         PopActiveSnapshot();
    2129            1 :         CommitTransactionCommand();
    2130            1 :         return false;
    2131              :     }
    2132              : 
    2133              :     /*
    2134              :      * Silently ignore tables that are temp tables of other backends ---
    2135              :      * trying to vacuum these will lead to great unhappiness, since their
    2136              :      * contents are probably not up-to-date on disk.  (We don't throw a
    2137              :      * warning here; it would just lead to chatter during a database-wide
    2138              :      * VACUUM.)
    2139              :      */
    2140       116612 :     if (RELATION_IS_OTHER_TEMP(rel))
    2141              :     {
    2142            1 :         relation_close(rel, lmode);
    2143            1 :         PopActiveSnapshot();
    2144            1 :         CommitTransactionCommand();
    2145            1 :         return false;
    2146              :     }
    2147              : 
    2148              :     /*
    2149              :      * Silently ignore partitioned tables as there is no work to be done.  The
    2150              :      * useful work is on their child partitions, which have been queued up for
    2151              :      * us separately.
    2152              :      */
    2153       116611 :     if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
    2154              :     {
    2155           93 :         relation_close(rel, lmode);
    2156           93 :         PopActiveSnapshot();
    2157           93 :         CommitTransactionCommand();
    2158              :         /* It's OK to proceed with ANALYZE on this table */
    2159           93 :         return true;
    2160              :     }
    2161              : 
    2162              :     /*
    2163              :      * Get a session-level lock too. This will protect our access to the
    2164              :      * relation across multiple transactions, so that we can vacuum the
    2165              :      * relation's TOAST table (if any) secure in the knowledge that no one is
    2166              :      * deleting the parent relation.
    2167              :      *
    2168              :      * NOTE: this cannot block, even if someone else is waiting for access,
    2169              :      * because the lock manager knows that both lock requests are from the
    2170              :      * same process.
    2171              :      */
    2172       116518 :     lockrelid = rel->rd_lockInfo.lockRelId;
    2173       116518 :     LockRelationIdForSession(&lockrelid, lmode);
    2174              : 
    2175              :     /*
    2176              :      * Set index_cleanup option based on index_cleanup reloption if it wasn't
    2177              :      * specified in VACUUM command, or when running in an autovacuum worker
    2178              :      */
    2179       116518 :     if (params.index_cleanup == VACOPTVALUE_UNSPECIFIED)
    2180              :     {
    2181              :         StdRdOptIndexCleanup vacuum_index_cleanup;
    2182              : 
    2183       116389 :         if (rel->rd_options == NULL)
    2184       115058 :             vacuum_index_cleanup = STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO;
    2185              :         else
    2186         1331 :             vacuum_index_cleanup =
    2187         1331 :                 ((StdRdOptions *) rel->rd_options)->vacuum_index_cleanup;
    2188              : 
    2189       116389 :         if (vacuum_index_cleanup == STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO)
    2190       116367 :             params.index_cleanup = VACOPTVALUE_AUTO;
    2191           22 :         else if (vacuum_index_cleanup == STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON)
    2192           11 :             params.index_cleanup = VACOPTVALUE_ENABLED;
    2193              :         else
    2194              :         {
    2195              :             Assert(vacuum_index_cleanup ==
    2196              :                    STDRD_OPTION_VACUUM_INDEX_CLEANUP_OFF);
    2197           11 :             params.index_cleanup = VACOPTVALUE_DISABLED;
    2198              :         }
    2199              :     }
    2200              : 
    2201              : #ifdef USE_INJECTION_POINTS
    2202       116518 :     if (params.index_cleanup == VACOPTVALUE_AUTO)
    2203       116370 :         INJECTION_POINT("vacuum-index-cleanup-auto", NULL);
    2204          148 :     else if (params.index_cleanup == VACOPTVALUE_DISABLED)
    2205          130 :         INJECTION_POINT("vacuum-index-cleanup-disabled", NULL);
    2206           18 :     else if (params.index_cleanup == VACOPTVALUE_ENABLED)
    2207           18 :         INJECTION_POINT("vacuum-index-cleanup-enabled", NULL);
    2208              : #endif
    2209              : 
    2210              :     /*
    2211              :      * Check if the vacuum_max_eager_freeze_failure_rate table storage
    2212              :      * parameter was specified. This overrides the GUC value.
    2213              :      */
    2214       116518 :     if (rel->rd_options != NULL &&
    2215         1337 :         ((StdRdOptions *) rel->rd_options)->vacuum_max_eager_freeze_failure_rate >= 0)
    2216            0 :         params.max_eager_freeze_failure_rate =
    2217            0 :             ((StdRdOptions *) rel->rd_options)->vacuum_max_eager_freeze_failure_rate;
    2218              : 
    2219              :     /*
    2220              :      * Set truncate option based on truncate reloption or GUC if it wasn't
    2221              :      * specified in VACUUM command, or when running in an autovacuum worker
    2222              :      */
    2223       116518 :     if (params.truncate == VACOPTVALUE_UNSPECIFIED)
    2224              :     {
    2225       116391 :         StdRdOptions *opts = (StdRdOptions *) rel->rd_options;
    2226              : 
    2227       116391 :         if (opts && opts->vacuum_truncate != PG_TERNARY_UNSET)
    2228              :         {
    2229           16 :             if (opts->vacuum_truncate == PG_TERNARY_TRUE)
    2230            5 :                 params.truncate = VACOPTVALUE_ENABLED;
    2231              :             else
    2232           11 :                 params.truncate = VACOPTVALUE_DISABLED;
    2233              :         }
    2234       116375 :         else if (vacuum_truncate)
    2235       116364 :             params.truncate = VACOPTVALUE_ENABLED;
    2236              :         else
    2237           11 :             params.truncate = VACOPTVALUE_DISABLED;
    2238              :     }
    2239              : 
    2240              : #ifdef USE_INJECTION_POINTS
    2241       116518 :     if (params.truncate == VACOPTVALUE_AUTO)
    2242            0 :         INJECTION_POINT("vacuum-truncate-auto", NULL);
    2243       116518 :     else if (params.truncate == VACOPTVALUE_DISABLED)
    2244          148 :         INJECTION_POINT("vacuum-truncate-disabled", NULL);
    2245       116370 :     else if (params.truncate == VACOPTVALUE_ENABLED)
    2246       116370 :         INJECTION_POINT("vacuum-truncate-enabled", NULL);
    2247              : #endif
    2248              : 
    2249              :     /*
    2250              :      * Remember the relation's TOAST relation for later, if the caller asked
    2251              :      * us to process it.  In VACUUM FULL, though, the toast table is
    2252              :      * automatically rebuilt by cluster_rel so we shouldn't recurse to it,
    2253              :      * unless PROCESS_MAIN is disabled.
    2254              :      */
    2255       116518 :     if ((params.options & VACOPT_PROCESS_TOAST) != 0 &&
    2256        14059 :         ((params.options & VACOPT_FULL) == 0 ||
    2257          193 :          (params.options & VACOPT_PROCESS_MAIN) == 0))
    2258        13869 :         toast_relid = rel->rd_rel->reltoastrelid;
    2259              :     else
    2260       102649 :         toast_relid = InvalidOid;
    2261              : 
    2262              :     /*
    2263              :      * Switch to the table owner's userid, so that any index functions are run
    2264              :      * as that user.  Also lock down security-restricted operations and
    2265              :      * arrange to make GUC variable changes local to this command. (This is
    2266              :      * unnecessary, but harmless, for lazy VACUUM.)
    2267              :      */
    2268       116518 :     GetUserIdAndSecContext(&save_userid, &save_sec_context);
    2269       116518 :     SetUserIdAndSecContext(rel->rd_rel->relowner,
    2270              :                            save_sec_context | SECURITY_RESTRICTED_OPERATION);
    2271       116518 :     save_nestlevel = NewGUCNestLevel();
    2272       116518 :     RestrictSearchPath();
    2273              : 
    2274              :     /*
    2275              :      * If PROCESS_MAIN is set (the default), it's time to vacuum the main
    2276              :      * relation.  Otherwise, we can skip this part.  If processing the TOAST
    2277              :      * table is required (e.g., PROCESS_TOAST is set), we force PROCESS_MAIN
    2278              :      * to be set when we recurse to the TOAST table.
    2279              :      */
    2280       116518 :     if (params.options & VACOPT_PROCESS_MAIN)
    2281              :     {
    2282              :         /*
    2283              :          * Do the actual work --- either FULL or "lazy" vacuum
    2284              :          */
    2285       116441 :         if (params.options & VACOPT_FULL)
    2286              :         {
    2287          190 :             ClusterParams cluster_params = {0};
    2288              : 
    2289          190 :             if ((params.options & VACOPT_VERBOSE) != 0)
    2290            1 :                 cluster_params.options |= CLUOPT_VERBOSE;
    2291              : 
    2292              :             /* VACUUM FULL is now a variant of CLUSTER; see cluster.c */
    2293          190 :             cluster_rel(rel, InvalidOid, &cluster_params);
    2294              :             /* cluster_rel closes the relation, but keeps lock */
    2295              : 
    2296          187 :             rel = NULL;
    2297              :         }
    2298              :         else
    2299       116251 :             table_relation_vacuum(rel, params, bstrategy);
    2300              :     }
    2301              : 
    2302              :     /* Roll back any GUC changes executed by index functions */
    2303       116515 :     AtEOXact_GUC(false, save_nestlevel);
    2304              : 
    2305              :     /* Restore userid and security context */
    2306       116515 :     SetUserIdAndSecContext(save_userid, save_sec_context);
    2307              : 
    2308              :     /* all done with this class, but hold lock until commit */
    2309       116515 :     if (rel)
    2310       116328 :         relation_close(rel, NoLock);
    2311              : 
    2312              :     /*
    2313              :      * Complete the transaction and free all temporary memory used.
    2314              :      */
    2315       116515 :     PopActiveSnapshot();
    2316       116515 :     CommitTransactionCommand();
    2317              : 
    2318              :     /*
    2319              :      * If the relation has a secondary toast rel, vacuum that too while we
    2320              :      * still hold the session lock on the main table.  Note however that
    2321              :      * "analyze" will not get done on the toast table.  This is good, because
    2322              :      * the toaster always uses hardcoded index access and statistics are
    2323              :      * totally unimportant for toast relations.
    2324              :      */
    2325       116515 :     if (toast_relid != InvalidOid)
    2326              :     {
    2327              :         /*
    2328              :          * Force VACOPT_PROCESS_MAIN so vacuum_rel() processes it.  Likewise,
    2329              :          * set toast_parent so that the privilege checks are done on the main
    2330              :          * relation.  NB: This is only safe to do because we hold a session
    2331              :          * lock on the main relation that prevents concurrent deletion.
    2332              :          */
    2333         4901 :         toast_vacuum_params.options |= VACOPT_PROCESS_MAIN;
    2334         4901 :         toast_vacuum_params.toast_parent = relid;
    2335              : 
    2336         4901 :         vacuum_rel(toast_relid, NULL, toast_vacuum_params, bstrategy);
    2337              :     }
    2338              : 
    2339              :     /*
    2340              :      * Now release the session-level lock on the main table.
    2341              :      */
    2342       116515 :     UnlockRelationIdForSession(&lockrelid, lmode);
    2343              : 
    2344              :     /* Report that we really did it. */
    2345       116515 :     return true;
    2346              : }
    2347              : 
    2348              : 
    2349              : /*
    2350              :  * Open all the vacuumable indexes of the given relation, obtaining the
    2351              :  * specified kind of lock on each.  Return an array of Relation pointers for
    2352              :  * the indexes into *Irel, and the number of indexes into *nindexes.
    2353              :  *
    2354              :  * We consider an index vacuumable if it is marked insertable (indisready).
    2355              :  * If it isn't, probably a CREATE INDEX CONCURRENTLY command failed early in
    2356              :  * execution, and what we have is too corrupt to be processable.  We will
    2357              :  * vacuum even if the index isn't indisvalid; this is important because in a
    2358              :  * unique index, uniqueness checks will be performed anyway and had better not
    2359              :  * hit dangling index pointers.
    2360              :  */
    2361              : void
    2362       124299 : vac_open_indexes(Relation relation, LOCKMODE lockmode,
    2363              :                  int *nindexes, Relation **Irel)
    2364              : {
    2365              :     List       *indexoidlist;
    2366              :     ListCell   *indexoidscan;
    2367              :     int         i;
    2368              : 
    2369              :     Assert(lockmode != NoLock);
    2370              : 
    2371       124299 :     indexoidlist = RelationGetIndexList(relation);
    2372              : 
    2373              :     /* allocate enough memory for all indexes */
    2374       124299 :     i = list_length(indexoidlist);
    2375              : 
    2376       124299 :     if (i > 0)
    2377       117019 :         *Irel = (Relation *) palloc(i * sizeof(Relation));
    2378              :     else
    2379         7280 :         *Irel = NULL;
    2380              : 
    2381              :     /* collect just the ready indexes */
    2382       124299 :     i = 0;
    2383       310404 :     foreach(indexoidscan, indexoidlist)
    2384              :     {
    2385       186105 :         Oid         indexoid = lfirst_oid(indexoidscan);
    2386              :         Relation    indrel;
    2387              : 
    2388       186105 :         indrel = index_open(indexoid, lockmode);
    2389       186105 :         if (indrel->rd_index->indisready)
    2390       186105 :             (*Irel)[i++] = indrel;
    2391              :         else
    2392            0 :             index_close(indrel, lockmode);
    2393              :     }
    2394              : 
    2395       124299 :     *nindexes = i;
    2396              : 
    2397       124299 :     list_free(indexoidlist);
    2398       124299 : }
    2399              : 
    2400              : /*
    2401              :  * Release the resources acquired by vac_open_indexes.  Optionally release
    2402              :  * the locks (say NoLock to keep 'em).
    2403              :  */
    2404              : void
    2405       124735 : vac_close_indexes(int nindexes, Relation *Irel, LOCKMODE lockmode)
    2406              : {
    2407       124735 :     if (Irel == NULL)
    2408         7719 :         return;
    2409              : 
    2410       303115 :     while (nindexes--)
    2411              :     {
    2412       186099 :         Relation    ind = Irel[nindexes];
    2413              : 
    2414       186099 :         index_close(ind, lockmode);
    2415              :     }
    2416       117016 :     pfree(Irel);
    2417              : }
    2418              : 
    2419              : /*
    2420              :  * vacuum_delay_point --- check for interrupts and cost-based delay.
    2421              :  *
    2422              :  * This should be called in each major loop of VACUUM processing,
    2423              :  * typically once per page processed.
    2424              :  */
    2425              : void
    2426     45238142 : vacuum_delay_point(bool is_analyze)
    2427              : {
    2428     45238142 :     double      msec = 0;
    2429              : 
    2430              :     /* Always check for interrupts */
    2431     45238142 :     CHECK_FOR_INTERRUPTS();
    2432              : 
    2433     45238142 :     if (InterruptPending ||
    2434     45238142 :         (!VacuumCostActive && !ConfigReloadPending))
    2435     39419678 :         return;
    2436              : 
    2437              :     /*
    2438              :      * Autovacuum workers should reload the configuration file if requested.
    2439              :      * This allows changes to [autovacuum_]vacuum_cost_limit and
    2440              :      * [autovacuum_]vacuum_cost_delay to take effect while a table is being
    2441              :      * vacuumed or analyzed.
    2442              :      */
    2443      5818464 :     if (ConfigReloadPending && AmAutoVacuumWorkerProcess())
    2444              :     {
    2445            0 :         ConfigReloadPending = false;
    2446            0 :         ProcessConfigFile(PGC_SIGHUP);
    2447            0 :         VacuumUpdateCosts();
    2448              :     }
    2449              : 
    2450              :     /*
    2451              :      * If we disabled cost-based delays after reloading the config file,
    2452              :      * return.
    2453              :      */
    2454      5818464 :     if (!VacuumCostActive)
    2455            0 :         return;
    2456              : 
    2457              :     /*
    2458              :      * For parallel vacuum, the delay is computed based on the shared cost
    2459              :      * balance.  See compute_parallel_delay.
    2460              :      */
    2461      5818464 :     if (VacuumSharedCostBalance != NULL)
    2462            0 :         msec = compute_parallel_delay();
    2463      5818464 :     else if (VacuumCostBalance >= vacuum_cost_limit)
    2464         3398 :         msec = vacuum_cost_delay * VacuumCostBalance / vacuum_cost_limit;
    2465              : 
    2466              :     /* Nap if appropriate */
    2467      5818464 :     if (msec > 0)
    2468              :     {
    2469              :         instr_time  delay_start;
    2470              : 
    2471         3398 :         if (msec > vacuum_cost_delay * 4)
    2472            8 :             msec = vacuum_cost_delay * 4;
    2473              : 
    2474         3398 :         if (track_cost_delay_timing)
    2475            0 :             INSTR_TIME_SET_CURRENT(delay_start);
    2476              : 
    2477         3398 :         pgstat_report_wait_start(WAIT_EVENT_VACUUM_DELAY);
    2478         3398 :         pg_usleep(msec * 1000);
    2479         3398 :         pgstat_report_wait_end();
    2480              : 
    2481         3398 :         if (track_cost_delay_timing)
    2482              :         {
    2483              :             instr_time  delay_end;
    2484              :             instr_time  delay;
    2485              : 
    2486            0 :             INSTR_TIME_SET_CURRENT(delay_end);
    2487            0 :             INSTR_TIME_SET_ZERO(delay);
    2488            0 :             INSTR_TIME_ACCUM_DIFF(delay, delay_end, delay_start);
    2489              : 
    2490              :             /*
    2491              :              * For parallel workers, we only report the delay time every once
    2492              :              * in a while to avoid overloading the leader with messages and
    2493              :              * interrupts.
    2494              :              */
    2495            0 :             if (IsParallelWorker())
    2496              :             {
    2497              :                 static instr_time last_report_time;
    2498              :                 instr_time  time_since_last_report;
    2499              : 
    2500              :                 Assert(!is_analyze);
    2501              : 
    2502              :                 /* Accumulate the delay time */
    2503            0 :                 parallel_vacuum_worker_delay_ns += INSTR_TIME_GET_NANOSEC(delay);
    2504              : 
    2505              :                 /* Calculate interval since last report */
    2506            0 :                 INSTR_TIME_SET_ZERO(time_since_last_report);
    2507            0 :                 INSTR_TIME_ACCUM_DIFF(time_since_last_report, delay_end, last_report_time);
    2508              : 
    2509              :                 /* If we haven't reported in a while, do so now */
    2510            0 :                 if (INSTR_TIME_GET_NANOSEC(time_since_last_report) >=
    2511              :                     PARALLEL_VACUUM_DELAY_REPORT_INTERVAL_NS)
    2512              :                 {
    2513            0 :                     pgstat_progress_parallel_incr_param(PROGRESS_VACUUM_DELAY_TIME,
    2514              :                                                         parallel_vacuum_worker_delay_ns);
    2515              : 
    2516              :                     /* Reset variables */
    2517            0 :                     last_report_time = delay_end;
    2518            0 :                     parallel_vacuum_worker_delay_ns = 0;
    2519              :                 }
    2520              :             }
    2521            0 :             else if (is_analyze)
    2522            0 :                 pgstat_progress_incr_param(PROGRESS_ANALYZE_DELAY_TIME,
    2523            0 :                                            INSTR_TIME_GET_NANOSEC(delay));
    2524              :             else
    2525            0 :                 pgstat_progress_incr_param(PROGRESS_VACUUM_DELAY_TIME,
    2526            0 :                                            INSTR_TIME_GET_NANOSEC(delay));
    2527              :         }
    2528              : 
    2529              :         /*
    2530              :          * We don't want to ignore postmaster death during very long vacuums
    2531              :          * with vacuum_cost_delay configured.  We can't use the usual
    2532              :          * WaitLatch() approach here because we want microsecond-based sleep
    2533              :          * durations above.
    2534              :          */
    2535         3398 :         if (IsUnderPostmaster && !PostmasterIsAlive())
    2536            0 :             exit(1);
    2537              : 
    2538         3398 :         VacuumCostBalance = 0;
    2539              : 
    2540              :         /*
    2541              :          * Balance and update limit values for autovacuum workers. We must do
    2542              :          * this periodically, as the number of workers across which we are
    2543              :          * balancing the limit may have changed.
    2544              :          *
    2545              :          * TODO: There may be better criteria for determining when to do this
    2546              :          * besides "check after napping".
    2547              :          */
    2548         3398 :         AutoVacuumUpdateCostLimit();
    2549              : 
    2550              :         /* Might have gotten an interrupt while sleeping */
    2551         3398 :         CHECK_FOR_INTERRUPTS();
    2552              :     }
    2553              : }
    2554              : 
    2555              : /*
    2556              :  * Computes the vacuum delay for parallel workers.
    2557              :  *
    2558              :  * The basic idea of a cost-based delay for parallel vacuum is to allow each
    2559              :  * worker to sleep in proportion to the share of work it's done.  We achieve this
    2560              :  * by allowing all parallel vacuum workers including the leader process to
    2561              :  * have a shared view of cost related parameters (mainly VacuumCostBalance).
    2562              :  * We allow each worker to update it as and when it has incurred any cost and
    2563              :  * then based on that decide whether it needs to sleep.  We compute the time
    2564              :  * to sleep for a worker based on the cost it has incurred
    2565              :  * (VacuumCostBalanceLocal) and then reduce the VacuumSharedCostBalance by
    2566              :  * that amount.  This avoids putting to sleep those workers which have done less
    2567              :  * I/O than other workers and therefore ensure that workers
    2568              :  * which are doing more I/O got throttled more.
    2569              :  *
    2570              :  * We allow a worker to sleep only if it has performed I/O above a certain
    2571              :  * threshold, which is calculated based on the number of active workers
    2572              :  * (VacuumActiveNWorkers), and the overall cost balance is more than
    2573              :  * VacuumCostLimit set by the system.  Testing reveals that we achieve
    2574              :  * the required throttling if we force a worker that has done more than 50%
    2575              :  * of its share of work to sleep.
    2576              :  */
    2577              : static double
    2578            0 : compute_parallel_delay(void)
    2579              : {
    2580            0 :     double      msec = 0;
    2581              :     uint32      shared_balance;
    2582              :     int         nworkers;
    2583              : 
    2584              :     /* Parallel vacuum must be active */
    2585              :     Assert(VacuumSharedCostBalance);
    2586              : 
    2587            0 :     nworkers = pg_atomic_read_u32(VacuumActiveNWorkers);
    2588              : 
    2589              :     /* At least count itself */
    2590              :     Assert(nworkers >= 1);
    2591              : 
    2592              :     /* Update the shared cost balance value atomically */
    2593            0 :     shared_balance = pg_atomic_add_fetch_u32(VacuumSharedCostBalance, VacuumCostBalance);
    2594              : 
    2595              :     /* Compute the total local balance for the current worker */
    2596            0 :     VacuumCostBalanceLocal += VacuumCostBalance;
    2597              : 
    2598            0 :     if ((shared_balance >= vacuum_cost_limit) &&
    2599            0 :         (VacuumCostBalanceLocal > 0.5 * ((double) vacuum_cost_limit / nworkers)))
    2600              :     {
    2601              :         /* Compute sleep time based on the local cost balance */
    2602            0 :         msec = vacuum_cost_delay * VacuumCostBalanceLocal / vacuum_cost_limit;
    2603            0 :         pg_atomic_sub_fetch_u32(VacuumSharedCostBalance, VacuumCostBalanceLocal);
    2604            0 :         VacuumCostBalanceLocal = 0;
    2605              :     }
    2606              : 
    2607              :     /*
    2608              :      * Reset the local balance as we accumulated it into the shared value.
    2609              :      */
    2610            0 :     VacuumCostBalance = 0;
    2611              : 
    2612            0 :     return msec;
    2613              : }
    2614              : 
    2615              : /*
    2616              :  * A wrapper function of defGetBoolean().
    2617              :  *
    2618              :  * This function returns VACOPTVALUE_ENABLED and VACOPTVALUE_DISABLED instead
    2619              :  * of true and false.
    2620              :  */
    2621              : static VacOptValue
    2622          164 : get_vacoptval_from_boolean(DefElem *def)
    2623              : {
    2624          164 :     return defGetBoolean(def) ? VACOPTVALUE_ENABLED : VACOPTVALUE_DISABLED;
    2625              : }
    2626              : 
    2627              : /*
    2628              :  *  vac_bulkdel_one_index() -- bulk-deletion for index relation.
    2629              :  *
    2630              :  * Returns bulk delete stats derived from input stats
    2631              :  */
    2632              : IndexBulkDeleteResult *
    2633         1280 : vac_bulkdel_one_index(IndexVacuumInfo *ivinfo, IndexBulkDeleteResult *istat,
    2634              :                       TidStore *dead_items, VacDeadItemsInfo *dead_items_info)
    2635              : {
    2636              :     /* Do bulk deletion */
    2637         1280 :     istat = index_bulk_delete(ivinfo, istat, vac_tid_reaped,
    2638              :                               dead_items);
    2639              : 
    2640         1280 :     ereport(ivinfo->message_level,
    2641              :             (errmsg("scanned index \"%s\" to remove %" PRId64 " row versions",
    2642              :                     RelationGetRelationName(ivinfo->index),
    2643              :                     dead_items_info->num_items)));
    2644              : 
    2645         1280 :     return istat;
    2646              : }
    2647              : 
    2648              : /*
    2649              :  *  vac_cleanup_one_index() -- do post-vacuum cleanup for index relation.
    2650              :  *
    2651              :  * Returns bulk delete stats derived from input stats
    2652              :  */
    2653              : IndexBulkDeleteResult *
    2654       142010 : vac_cleanup_one_index(IndexVacuumInfo *ivinfo, IndexBulkDeleteResult *istat)
    2655              : {
    2656       142010 :     istat = index_vacuum_cleanup(ivinfo, istat);
    2657              : 
    2658       142010 :     if (istat)
    2659         1400 :         ereport(ivinfo->message_level,
    2660              :                 (errmsg("index \"%s\" now contains %.0f row versions in %u pages",
    2661              :                         RelationGetRelationName(ivinfo->index),
    2662              :                         istat->num_index_tuples,
    2663              :                         istat->num_pages),
    2664              :                  errdetail("%.0f index row versions were removed.\n"
    2665              :                            "%u index pages were newly deleted.\n"
    2666              :                            "%u index pages are currently deleted, of which %u are currently reusable.",
    2667              :                            istat->tuples_removed,
    2668              :                            istat->pages_newly_deleted,
    2669              :                            istat->pages_deleted, istat->pages_free)));
    2670              : 
    2671       142010 :     return istat;
    2672              : }
    2673              : 
    2674              : /*
    2675              :  *  vac_tid_reaped() -- is a particular tid deletable?
    2676              :  *
    2677              :  *      This has the right signature to be an IndexBulkDeleteCallback.
    2678              :  */
    2679              : static bool
    2680      3476191 : vac_tid_reaped(ItemPointer itemptr, void *state)
    2681              : {
    2682      3476191 :     TidStore   *dead_items = (TidStore *) state;
    2683              : 
    2684      3476191 :     return TidStoreIsMember(dead_items, itemptr);
    2685              : }
        

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