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vacuum.c File Reference
#include "postgres.h"
#include <math.h>
#include "access/clog.h"
#include "access/commit_ts.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/multixact.h"
#include "access/transam.h"
#include "access/xact.h"
#include "catalog/namespace.h"
#include "catalog/pg_database.h"
#include "catalog/pg_inherits_fn.h"
#include "catalog/pg_namespace.h"
#include "commands/cluster.h"
#include "commands/vacuum.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/autovacuum.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "utils/acl.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/tqual.h"
Include dependency graph for vacuum.c:

Go to the source code of this file.

Functions

static Listget_rel_oids (Oid relid, const RangeVar *vacrel)
 
static void vac_truncate_clog (TransactionId frozenXID, MultiXactId minMulti, TransactionId lastSaneFrozenXid, MultiXactId lastSaneMinMulti)
 
static bool vacuum_rel (Oid relid, RangeVar *relation, int options, VacuumParams *params)
 
void ExecVacuum (VacuumStmt *vacstmt, bool isTopLevel)
 
void vacuum (int options, RangeVar *relation, Oid relid, VacuumParams *params, List *va_cols, BufferAccessStrategy bstrategy, bool isTopLevel)
 
void vacuum_set_xid_limits (Relation rel, int freeze_min_age, int freeze_table_age, int multixact_freeze_min_age, int multixact_freeze_table_age, TransactionId *oldestXmin, TransactionId *freezeLimit, TransactionId *xidFullScanLimit, MultiXactId *multiXactCutoff, MultiXactId *mxactFullScanLimit)
 
double vac_estimate_reltuples (Relation relation, bool is_analyze, BlockNumber total_pages, BlockNumber scanned_pages, double scanned_tuples)
 
void vac_update_relstats (Relation relation, BlockNumber num_pages, double num_tuples, BlockNumber num_all_visible_pages, bool hasindex, TransactionId frozenxid, MultiXactId minmulti, bool in_outer_xact)
 
void vac_update_datfrozenxid (void)
 
void vac_open_indexes (Relation relation, LOCKMODE lockmode, int *nindexes, Relation **Irel)
 
void vac_close_indexes (int nindexes, Relation *Irel, LOCKMODE lockmode)
 
void vacuum_delay_point (void)
 

Variables

int vacuum_freeze_min_age
 
int vacuum_freeze_table_age
 
int vacuum_multixact_freeze_min_age
 
int vacuum_multixact_freeze_table_age
 
static MemoryContext vac_context = NULL
 
static BufferAccessStrategy vac_strategy
 

Function Documentation

void ExecVacuum ( VacuumStmt vacstmt,
bool  isTopLevel 
)

Definition at line 85 of file vacuum.c.

References Assert, VacuumParams::freeze_min_age, VacuumParams::freeze_table_age, InvalidOid, VacuumParams::is_wraparound, VacuumParams::log_min_duration, VacuumParams::multixact_freeze_min_age, VacuumParams::multixact_freeze_table_age, NIL, NULL, VacuumStmt::options, VacuumStmt::relation, VacuumStmt::va_cols, VACOPT_ANALYZE, VACOPT_FREEZE, VACOPT_FULL, VACOPT_SKIPTOAST, VACOPT_VACUUM, and vacuum().

Referenced by standard_ProcessUtility().

86 {
87  VacuumParams params;
88 
89  /* sanity checks on options */
91  Assert((vacstmt->options & VACOPT_VACUUM) ||
92  !(vacstmt->options & (VACOPT_FULL | VACOPT_FREEZE)));
93  Assert((vacstmt->options & VACOPT_ANALYZE) || vacstmt->va_cols == NIL);
94  Assert(!(vacstmt->options & VACOPT_SKIPTOAST));
95 
96  /*
97  * All freeze ages are zero if the FREEZE option is given; otherwise pass
98  * them as -1 which means to use the default values.
99  */
100  if (vacstmt->options & VACOPT_FREEZE)
101  {
102  params.freeze_min_age = 0;
103  params.freeze_table_age = 0;
104  params.multixact_freeze_min_age = 0;
105  params.multixact_freeze_table_age = 0;
106  }
107  else
108  {
109  params.freeze_min_age = -1;
110  params.freeze_table_age = -1;
111  params.multixact_freeze_min_age = -1;
112  params.multixact_freeze_table_age = -1;
113  }
114 
115  /* user-invoked vacuum is never "for wraparound" */
116  params.is_wraparound = false;
117 
118  /* user-invoked vacuum never uses this parameter */
119  params.log_min_duration = -1;
120 
121  /* Now go through the common routine */
122  vacuum(vacstmt->options, vacstmt->relation, InvalidOid, &params,
123  vacstmt->va_cols, NULL, isTopLevel);
124 }
#define NIL
Definition: pg_list.h:69
int multixact_freeze_table_age
Definition: vacuum.h:142
int freeze_table_age
Definition: vacuum.h:139
int freeze_min_age
Definition: vacuum.h:138
bool is_wraparound
Definition: vacuum.h:144
List * va_cols
Definition: parsenodes.h:3098
#define InvalidOid
Definition: postgres_ext.h:36
void vacuum(int options, RangeVar *relation, Oid relid, VacuumParams *params, List *va_cols, BufferAccessStrategy bstrategy, bool isTopLevel)
Definition: vacuum.c:149
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
RangeVar * relation
Definition: parsenodes.h:3097
int log_min_duration
Definition: vacuum.h:145
int multixact_freeze_min_age
Definition: vacuum.h:140
static List * get_rel_oids ( Oid  relid,
const RangeVar vacrel 
)
static

Definition at line 382 of file vacuum.c.

References AccessShareLock, elog, ERROR, find_all_inheritors(), ForwardScanDirection, GETSTRUCT, heap_beginscan_catalog(), heap_close, heap_endscan(), heap_getnext(), heap_open(), HeapTupleGetOid, HeapTupleIsValid, lappend_oid(), list_concat(), MemoryContextSwitchTo(), NIL, NoLock, NULL, ObjectIdGetDatum, OidIsValid, RangeVarGetRelid, RelationRelationId, ReleaseSysCache(), RELKIND_MATVIEW, RELKIND_PARTITIONED_TABLE, RELKIND_RELATION, RELOID, and SearchSysCache1.

Referenced by vacuum().

383 {
384  List *oid_list = NIL;
385  MemoryContext oldcontext;
386 
387  /* OID supplied by VACUUM's caller? */
388  if (OidIsValid(relid))
389  {
390  oldcontext = MemoryContextSwitchTo(vac_context);
391  oid_list = lappend_oid(oid_list, relid);
392  MemoryContextSwitchTo(oldcontext);
393  }
394  else if (vacrel)
395  {
396  /* Process a specific relation */
397  Oid relid;
398  HeapTuple tuple;
399  Form_pg_class classForm;
400  bool include_parts;
401 
402  /*
403  * Since we don't take a lock here, the relation might be gone, or the
404  * RangeVar might no longer refer to the OID we look up here. In the
405  * former case, VACUUM will do nothing; in the latter case, it will
406  * process the OID we looked up here, rather than the new one. Neither
407  * is ideal, but there's little practical alternative, since we're
408  * going to commit this transaction and begin a new one between now
409  * and then.
410  */
411  relid = RangeVarGetRelid(vacrel, NoLock, false);
412 
413  /*
414  * To check whether the relation is a partitioned table, fetch its
415  * syscache entry.
416  */
417  tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
418  if (!HeapTupleIsValid(tuple))
419  elog(ERROR, "cache lookup failed for relation %u", relid);
420  classForm = (Form_pg_class) GETSTRUCT(tuple);
421  include_parts = (classForm->relkind == RELKIND_PARTITIONED_TABLE);
422  ReleaseSysCache(tuple);
423 
424  /*
425  * Make relation list entries for this guy and its partitions, if any.
426  * Note that the list returned by find_all_inheritors() include the
427  * passed-in OID at its head. Also note that we did not request a
428  * lock to be taken to match what would be done otherwise.
429  */
430  oldcontext = MemoryContextSwitchTo(vac_context);
431  if (include_parts)
432  oid_list = list_concat(oid_list,
433  find_all_inheritors(relid, NoLock, NULL));
434  else
435  oid_list = lappend_oid(oid_list, relid);
436  MemoryContextSwitchTo(oldcontext);
437  }
438  else
439  {
440  /*
441  * Process all plain relations and materialized views listed in
442  * pg_class
443  */
444  Relation pgclass;
445  HeapScanDesc scan;
446  HeapTuple tuple;
447 
449 
450  scan = heap_beginscan_catalog(pgclass, 0, NULL);
451 
452  while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
453  {
454  Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
455 
456  /*
457  * We include partitioned tables here; depending on which
458  * operation is to be performed, caller will decide whether to
459  * process or ignore them.
460  */
461  if (classForm->relkind != RELKIND_RELATION &&
462  classForm->relkind != RELKIND_MATVIEW &&
463  classForm->relkind != RELKIND_PARTITIONED_TABLE)
464  continue;
465 
466  /* Make a relation list entry for this guy */
467  oldcontext = MemoryContextSwitchTo(vac_context);
468  oid_list = lappend_oid(oid_list, HeapTupleGetOid(tuple));
469  MemoryContextSwitchTo(oldcontext);
470  }
471 
472  heap_endscan(scan);
473  heap_close(pgclass, AccessShareLock);
474  }
475 
476  return oid_list;
477 }
#define NIL
Definition: pg_list.h:69
#define GETSTRUCT(TUP)
Definition: htup_details.h:656
void heap_endscan(HeapScanDesc scan)
Definition: heapam.c:1578
#define RangeVarGetRelid(relation, lockmode, missing_ok)
Definition: namespace.h:53
#define RelationRelationId
Definition: pg_class.h:29
#define RELKIND_MATVIEW
Definition: pg_class.h:165
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
#define AccessShareLock
Definition: lockdefs.h:36
List * list_concat(List *list1, List *list2)
Definition: list.c:321
#define heap_close(r, l)
Definition: heapam.h:97
unsigned int Oid
Definition: postgres_ext.h:31
List * lappend_oid(List *list, Oid datum)
Definition: list.c:164
#define OidIsValid(objectId)
Definition: c.h:538
#define SearchSysCache1(cacheId, key1)
Definition: syscache.h:156
#define ObjectIdGetDatum(X)
Definition: postgres.h:513
#define ERROR
Definition: elog.h:43
#define NoLock
Definition: lockdefs.h:34
static MemoryContext vac_context
Definition: vacuum.c:65
HeapScanDesc heap_beginscan_catalog(Relation relation, int nkeys, ScanKey key)
Definition: heapam.c:1399
#define RELKIND_PARTITIONED_TABLE
Definition: pg_class.h:168
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:1117
HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction)
Definition: heapam.c:1794
Relation heap_open(Oid relationId, LOCKMODE lockmode)
Definition: heapam.c:1284
#define HeapTupleIsValid(tuple)
Definition: htup.h:77
#define NULL
Definition: c.h:229
FormData_pg_class * Form_pg_class
Definition: pg_class.h:95
List * find_all_inheritors(Oid parentrelId, LOCKMODE lockmode, List **numparents)
Definition: pg_inherits.c:167
#define elog
Definition: elog.h:219
#define HeapTupleGetOid(tuple)
Definition: htup_details.h:695
#define RELKIND_RELATION
Definition: pg_class.h:160
Definition: pg_list.h:45
void vac_close_indexes ( int  nindexes,
Relation Irel,
LOCKMODE  lockmode 
)

Definition at line 1539 of file vacuum.c.

References index_close(), NULL, and pfree().

Referenced by do_analyze_rel(), and lazy_vacuum_rel().

1540 {
1541  if (Irel == NULL)
1542  return;
1543 
1544  while (nindexes--)
1545  {
1546  Relation ind = Irel[nindexes];
1547 
1548  index_close(ind, lockmode);
1549  }
1550  pfree(Irel);
1551 }
void pfree(void *pointer)
Definition: mcxt.c:950
#define NULL
Definition: c.h:229
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:176
double vac_estimate_reltuples ( Relation  relation,
bool  is_analyze,
BlockNumber  total_pages,
BlockNumber  scanned_pages,
double  scanned_tuples 
)

Definition at line 685 of file vacuum.c.

References RelationData::rd_rel.

Referenced by acquire_sample_rows(), lazy_scan_heap(), and statapprox_heap().

689 {
690  BlockNumber old_rel_pages = relation->rd_rel->relpages;
691  double old_rel_tuples = relation->rd_rel->reltuples;
692  double old_density;
693  double new_density;
694  double multiplier;
695  double updated_density;
696 
697  /* If we did scan the whole table, just use the count as-is */
698  if (scanned_pages >= total_pages)
699  return scanned_tuples;
700 
701  /*
702  * If scanned_pages is zero but total_pages isn't, keep the existing value
703  * of reltuples. (Note: callers should avoid updating the pg_class
704  * statistics in this situation, since no new information has been
705  * provided.)
706  */
707  if (scanned_pages == 0)
708  return old_rel_tuples;
709 
710  /*
711  * If old value of relpages is zero, old density is indeterminate; we
712  * can't do much except scale up scanned_tuples to match total_pages.
713  */
714  if (old_rel_pages == 0)
715  return floor((scanned_tuples / scanned_pages) * total_pages + 0.5);
716 
717  /*
718  * Okay, we've covered the corner cases. The normal calculation is to
719  * convert the old measurement to a density (tuples per page), then update
720  * the density using an exponential-moving-average approach, and finally
721  * compute reltuples as updated_density * total_pages.
722  *
723  * For ANALYZE, the moving average multiplier is just the fraction of the
724  * table's pages we scanned. This is equivalent to assuming that the
725  * tuple density in the unscanned pages didn't change. Of course, it
726  * probably did, if the new density measurement is different. But over
727  * repeated cycles, the value of reltuples will converge towards the
728  * correct value, if repeated measurements show the same new density.
729  *
730  * For VACUUM, the situation is a bit different: we have looked at a
731  * nonrandom sample of pages, but we know for certain that the pages we
732  * didn't look at are precisely the ones that haven't changed lately.
733  * Thus, there is a reasonable argument for doing exactly the same thing
734  * as for the ANALYZE case, that is use the old density measurement as the
735  * value for the unscanned pages.
736  *
737  * This logic could probably use further refinement.
738  */
739  old_density = old_rel_tuples / old_rel_pages;
740  new_density = scanned_tuples / scanned_pages;
741  multiplier = (double) scanned_pages / (double) total_pages;
742  updated_density = old_density + (new_density - old_density) * multiplier;
743  return floor(updated_density * total_pages + 0.5);
744 }
uint32 BlockNumber
Definition: block.h:31
Form_pg_class rd_rel
Definition: rel.h:114
void vac_open_indexes ( Relation  relation,
LOCKMODE  lockmode,
int *  nindexes,
Relation **  Irel 
)

Definition at line 1496 of file vacuum.c.

References Assert, i, index_close(), index_open(), IndexIsReady, lfirst_oid, list_free(), list_length(), NoLock, NULL, palloc(), RelationData::rd_index, and RelationGetIndexList().

Referenced by do_analyze_rel(), and lazy_vacuum_rel().

1498 {
1499  List *indexoidlist;
1500  ListCell *indexoidscan;
1501  int i;
1502 
1503  Assert(lockmode != NoLock);
1504 
1505  indexoidlist = RelationGetIndexList(relation);
1506 
1507  /* allocate enough memory for all indexes */
1508  i = list_length(indexoidlist);
1509 
1510  if (i > 0)
1511  *Irel = (Relation *) palloc(i * sizeof(Relation));
1512  else
1513  *Irel = NULL;
1514 
1515  /* collect just the ready indexes */
1516  i = 0;
1517  foreach(indexoidscan, indexoidlist)
1518  {
1519  Oid indexoid = lfirst_oid(indexoidscan);
1520  Relation indrel;
1521 
1522  indrel = index_open(indexoid, lockmode);
1523  if (IndexIsReady(indrel->rd_index))
1524  (*Irel)[i++] = indrel;
1525  else
1526  index_close(indrel, lockmode);
1527  }
1528 
1529  *nindexes = i;
1530 
1531  list_free(indexoidlist);
1532 }
#define IndexIsReady(indexForm)
Definition: pg_index.h:108
unsigned int Oid
Definition: postgres_ext.h:31
Form_pg_index rd_index
Definition: rel.h:159
#define NoLock
Definition: lockdefs.h:34
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static int list_length(const List *l)
Definition: pg_list.h:89
List * RelationGetIndexList(Relation relation)
Definition: relcache.c:4349
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:176
void * palloc(Size size)
Definition: mcxt.c:849
void list_free(List *list)
Definition: list.c:1133
int i
Definition: pg_list.h:45
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:151
#define lfirst_oid(lc)
Definition: pg_list.h:108
static void vac_truncate_clog ( TransactionId  frozenXID,
MultiXactId  minMulti,
TransactionId  lastSaneFrozenXid,
MultiXactId  lastSaneMinMulti 
)
static

Definition at line 1086 of file vacuum.c.

References AccessShareLock, AdvanceOldestCommitTsXid(), Assert, DatabaseRelationId, ereport, errdetail(), errmsg(), FormData_pg_database, ForwardScanDirection, GETSTRUCT, heap_beginscan_catalog(), heap_close, heap_endscan(), heap_getnext(), heap_open(), HeapTupleGetOid, MultiXactIdIsValid, MultiXactIdPrecedes(), MyDatabaseId, NULL, ReadNewTransactionId(), SetMultiXactIdLimit(), SetTransactionIdLimit(), TransactionIdIsNormal, TransactionIdPrecedes(), TruncateCLOG(), TruncateCommitTs(), TruncateMultiXact(), and WARNING.

Referenced by vac_update_datfrozenxid().

1090 {
1091  TransactionId nextXID = ReadNewTransactionId();
1092  Relation relation;
1093  HeapScanDesc scan;
1094  HeapTuple tuple;
1095  Oid oldestxid_datoid;
1096  Oid minmulti_datoid;
1097  bool bogus = false;
1098  bool frozenAlreadyWrapped = false;
1099 
1100  /* init oldest datoids to sync with my frozenXID/minMulti values */
1101  oldestxid_datoid = MyDatabaseId;
1102  minmulti_datoid = MyDatabaseId;
1103 
1104  /*
1105  * Scan pg_database to compute the minimum datfrozenxid/datminmxid
1106  *
1107  * Since vac_update_datfrozenxid updates datfrozenxid/datminmxid in-place,
1108  * the values could change while we look at them. Fetch each one just
1109  * once to ensure sane behavior of the comparison logic. (Here, as in
1110  * many other places, we assume that fetching or updating an XID in shared
1111  * storage is atomic.)
1112  *
1113  * Note: we need not worry about a race condition with new entries being
1114  * inserted by CREATE DATABASE. Any such entry will have a copy of some
1115  * existing DB's datfrozenxid, and that source DB cannot be ours because
1116  * of the interlock against copying a DB containing an active backend.
1117  * Hence the new entry will not reduce the minimum. Also, if two VACUUMs
1118  * concurrently modify the datfrozenxid's of different databases, the
1119  * worst possible outcome is that pg_xact is not truncated as aggressively
1120  * as it could be.
1121  */
1123 
1124  scan = heap_beginscan_catalog(relation, 0, NULL);
1125 
1126  while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
1127  {
1128  volatile FormData_pg_database *dbform = (Form_pg_database) GETSTRUCT(tuple);
1129  TransactionId datfrozenxid = dbform->datfrozenxid;
1130  TransactionId datminmxid = dbform->datminmxid;
1131 
1132  Assert(TransactionIdIsNormal(datfrozenxid));
1133  Assert(MultiXactIdIsValid(datminmxid));
1134 
1135  /*
1136  * If things are working properly, no database should have a
1137  * datfrozenxid or datminmxid that is "in the future". However, such
1138  * cases have been known to arise due to bugs in pg_upgrade. If we
1139  * see any entries that are "in the future", chicken out and don't do
1140  * anything. This ensures we won't truncate clog before those
1141  * databases have been scanned and cleaned up. (We will issue the
1142  * "already wrapped" warning if appropriate, though.)
1143  */
1144  if (TransactionIdPrecedes(lastSaneFrozenXid, datfrozenxid) ||
1145  MultiXactIdPrecedes(lastSaneMinMulti, datminmxid))
1146  bogus = true;
1147 
1148  if (TransactionIdPrecedes(nextXID, datfrozenxid))
1149  frozenAlreadyWrapped = true;
1150  else if (TransactionIdPrecedes(datfrozenxid, frozenXID))
1151  {
1152  frozenXID = datfrozenxid;
1153  oldestxid_datoid = HeapTupleGetOid(tuple);
1154  }
1155 
1156  if (MultiXactIdPrecedes(datminmxid, minMulti))
1157  {
1158  minMulti = datminmxid;
1159  minmulti_datoid = HeapTupleGetOid(tuple);
1160  }
1161  }
1162 
1163  heap_endscan(scan);
1164 
1165  heap_close(relation, AccessShareLock);
1166 
1167  /*
1168  * Do not truncate CLOG if we seem to have suffered wraparound already;
1169  * the computed minimum XID might be bogus. This case should now be
1170  * impossible due to the defenses in GetNewTransactionId, but we keep the
1171  * test anyway.
1172  */
1173  if (frozenAlreadyWrapped)
1174  {
1175  ereport(WARNING,
1176  (errmsg("some databases have not been vacuumed in over 2 billion transactions"),
1177  errdetail("You might have already suffered transaction-wraparound data loss.")));
1178  return;
1179  }
1180 
1181  /* chicken out if data is bogus in any other way */
1182  if (bogus)
1183  return;
1184 
1185  /*
1186  * Advance the oldest value for commit timestamps before truncating, so
1187  * that if a user requests a timestamp for a transaction we're truncating
1188  * away right after this point, they get NULL instead of an ugly "file not
1189  * found" error from slru.c. This doesn't matter for xact/multixact
1190  * because they are not subject to arbitrary lookups from users.
1191  */
1192  AdvanceOldestCommitTsXid(frozenXID);
1193 
1194  /*
1195  * Truncate CLOG, multixact and CommitTs to the oldest computed value.
1196  */
1197  TruncateCLOG(frozenXID, oldestxid_datoid);
1198  TruncateCommitTs(frozenXID);
1199  TruncateMultiXact(minMulti, minmulti_datoid);
1200 
1201  /*
1202  * Update the wrap limit for GetNewTransactionId and creation of new
1203  * MultiXactIds. Note: these functions will also signal the postmaster
1204  * for an(other) autovac cycle if needed. XXX should we avoid possibly
1205  * signalling twice?
1206  */
1207  SetTransactionIdLimit(frozenXID, oldestxid_datoid);
1208  SetMultiXactIdLimit(minMulti, minmulti_datoid, false);
1209 }
#define GETSTRUCT(TUP)
Definition: htup_details.h:656
void heap_endscan(HeapScanDesc scan)
Definition: heapam.c:1578
void TruncateCLOG(TransactionId oldestXact, Oid oldestxid_datoid)
Definition: clog.c:658
uint32 TransactionId
Definition: c.h:397
FormData_pg_database * Form_pg_database
Definition: pg_database.h:57
#define DatabaseRelationId
Definition: pg_database.h:29
#define AccessShareLock
Definition: lockdefs.h:36
#define heap_close(r, l)
Definition: heapam.h:97
unsigned int Oid
Definition: postgres_ext.h:31
void AdvanceOldestCommitTsXid(TransactionId oldestXact)
Definition: commit_ts.c:876
int errdetail(const char *fmt,...)
Definition: elog.c:873
TransactionId ReadNewTransactionId(void)
Definition: varsup.c:250
#define MultiXactIdIsValid(multi)
Definition: multixact.h:27
HeapScanDesc heap_beginscan_catalog(Relation relation, int nkeys, ScanKey key)
Definition: heapam.c:1399
#define ereport(elevel, rest)
Definition: elog.h:122
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
void TruncateCommitTs(TransactionId oldestXact)
Definition: commit_ts.c:823
#define WARNING
Definition: elog.h:40
Oid MyDatabaseId
Definition: globals.c:77
HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction)
Definition: heapam.c:1794
Relation heap_open(Oid relationId, LOCKMODE lockmode)
Definition: heapam.c:1284
void SetMultiXactIdLimit(MultiXactId oldest_datminmxid, Oid oldest_datoid, bool is_startup)
Definition: multixact.c:2194
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
void SetTransactionIdLimit(TransactionId oldest_datfrozenxid, Oid oldest_datoid)
Definition: varsup.c:288
bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
Definition: multixact.c:3140
int errmsg(const char *fmt,...)
Definition: elog.c:797
FormData_pg_database
Definition: pg_database.h:50
#define HeapTupleGetOid(tuple)
Definition: htup_details.h:695
#define TransactionIdIsNormal(xid)
Definition: transam.h:42
void TruncateMultiXact(MultiXactId newOldestMulti, Oid newOldestMultiDB)
Definition: multixact.c:2933
void vac_update_datfrozenxid ( void  )

Definition at line 922 of file vacuum.c.

References AccessShareLock, Assert, DATABASEOID, DatabaseRelationId, elog, ERROR, ForceTransactionIdLimitUpdate(), GetOldestMultiXactId(), GetOldestXmin(), GETSTRUCT, heap_close, heap_freetuple(), heap_inplace_update(), heap_open(), HeapTupleIsValid, InvalidOid, MultiXactIdIsValid, MultiXactIdPrecedes(), MyDatabaseId, NULL, ObjectIdGetDatum, PROCARRAY_FLAGS_VACUUM, ReadNewTransactionId(), ReadNextMultiXactId(), RelationRelationId, RELKIND_MATVIEW, RELKIND_RELATION, RELKIND_TOASTVALUE, RowExclusiveLock, SearchSysCacheCopy1, systable_beginscan(), systable_endscan(), systable_getnext(), TransactionIdIsNormal, TransactionIdPrecedes(), and vac_truncate_clog().

Referenced by do_autovacuum(), and vacuum().

923 {
924  HeapTuple tuple;
925  Form_pg_database dbform;
926  Relation relation;
927  SysScanDesc scan;
928  HeapTuple classTup;
929  TransactionId newFrozenXid;
930  MultiXactId newMinMulti;
931  TransactionId lastSaneFrozenXid;
932  MultiXactId lastSaneMinMulti;
933  bool bogus = false;
934  bool dirty = false;
935 
936  /*
937  * Initialize the "min" calculation with GetOldestXmin, which is a
938  * reasonable approximation to the minimum relfrozenxid for not-yet-
939  * committed pg_class entries for new tables; see AddNewRelationTuple().
940  * So we cannot produce a wrong minimum by starting with this.
941  */
942  newFrozenXid = GetOldestXmin(NULL, PROCARRAY_FLAGS_VACUUM);
943 
944  /*
945  * Similarly, initialize the MultiXact "min" with the value that would be
946  * used on pg_class for new tables. See AddNewRelationTuple().
947  */
948  newMinMulti = GetOldestMultiXactId();
949 
950  /*
951  * Identify the latest relfrozenxid and relminmxid values that we could
952  * validly see during the scan. These are conservative values, but it's
953  * not really worth trying to be more exact.
954  */
955  lastSaneFrozenXid = ReadNewTransactionId();
956  lastSaneMinMulti = ReadNextMultiXactId();
957 
958  /*
959  * We must seqscan pg_class to find the minimum Xid, because there is no
960  * index that can help us here.
961  */
963 
964  scan = systable_beginscan(relation, InvalidOid, false,
965  NULL, 0, NULL);
966 
967  while ((classTup = systable_getnext(scan)) != NULL)
968  {
969  Form_pg_class classForm = (Form_pg_class) GETSTRUCT(classTup);
970 
971  /*
972  * Only consider relations able to hold unfrozen XIDs (anything else
973  * should have InvalidTransactionId in relfrozenxid anyway.)
974  */
975  if (classForm->relkind != RELKIND_RELATION &&
976  classForm->relkind != RELKIND_MATVIEW &&
977  classForm->relkind != RELKIND_TOASTVALUE)
978  continue;
979 
980  Assert(TransactionIdIsNormal(classForm->relfrozenxid));
981  Assert(MultiXactIdIsValid(classForm->relminmxid));
982 
983  /*
984  * If things are working properly, no relation should have a
985  * relfrozenxid or relminmxid that is "in the future". However, such
986  * cases have been known to arise due to bugs in pg_upgrade. If we
987  * see any entries that are "in the future", chicken out and don't do
988  * anything. This ensures we won't truncate clog before those
989  * relations have been scanned and cleaned up.
990  */
991  if (TransactionIdPrecedes(lastSaneFrozenXid, classForm->relfrozenxid) ||
992  MultiXactIdPrecedes(lastSaneMinMulti, classForm->relminmxid))
993  {
994  bogus = true;
995  break;
996  }
997 
998  if (TransactionIdPrecedes(classForm->relfrozenxid, newFrozenXid))
999  newFrozenXid = classForm->relfrozenxid;
1000 
1001  if (MultiXactIdPrecedes(classForm->relminmxid, newMinMulti))
1002  newMinMulti = classForm->relminmxid;
1003  }
1004 
1005  /* we're done with pg_class */
1006  systable_endscan(scan);
1007  heap_close(relation, AccessShareLock);
1008 
1009  /* chicken out if bogus data found */
1010  if (bogus)
1011  return;
1012 
1013  Assert(TransactionIdIsNormal(newFrozenXid));
1014  Assert(MultiXactIdIsValid(newMinMulti));
1015 
1016  /* Now fetch the pg_database tuple we need to update. */
1018 
1019  /* Fetch a copy of the tuple to scribble on */
1021  if (!HeapTupleIsValid(tuple))
1022  elog(ERROR, "could not find tuple for database %u", MyDatabaseId);
1023  dbform = (Form_pg_database) GETSTRUCT(tuple);
1024 
1025  /*
1026  * As in vac_update_relstats(), we ordinarily don't want to let
1027  * datfrozenxid go backward; but if it's "in the future" then it must be
1028  * corrupt and it seems best to overwrite it.
1029  */
1030  if (dbform->datfrozenxid != newFrozenXid &&
1031  (TransactionIdPrecedes(dbform->datfrozenxid, newFrozenXid) ||
1032  TransactionIdPrecedes(lastSaneFrozenXid, dbform->datfrozenxid)))
1033  {
1034  dbform->datfrozenxid = newFrozenXid;
1035  dirty = true;
1036  }
1037  else
1038  newFrozenXid = dbform->datfrozenxid;
1039 
1040  /* Ditto for datminmxid */
1041  if (dbform->datminmxid != newMinMulti &&
1042  (MultiXactIdPrecedes(dbform->datminmxid, newMinMulti) ||
1043  MultiXactIdPrecedes(lastSaneMinMulti, dbform->datminmxid)))
1044  {
1045  dbform->datminmxid = newMinMulti;
1046  dirty = true;
1047  }
1048  else
1049  newMinMulti = dbform->datminmxid;
1050 
1051  if (dirty)
1052  heap_inplace_update(relation, tuple);
1053 
1054  heap_freetuple(tuple);
1055  heap_close(relation, RowExclusiveLock);
1056 
1057  /*
1058  * If we were able to advance datfrozenxid or datminmxid, see if we can
1059  * truncate pg_xact and/or pg_multixact. Also do it if the shared
1060  * XID-wrap-limit info is stale, since this action will update that too.
1061  */
1062  if (dirty || ForceTransactionIdLimitUpdate())
1063  vac_truncate_clog(newFrozenXid, newMinMulti,
1064  lastSaneFrozenXid, lastSaneMinMulti);
1065 }
void systable_endscan(SysScanDesc sysscan)
Definition: genam.c:499
#define GETSTRUCT(TUP)
Definition: htup_details.h:656
uint32 TransactionId
Definition: c.h:397
FormData_pg_database * Form_pg_database
Definition: pg_database.h:57
#define DatabaseRelationId
Definition: pg_database.h:29
#define RelationRelationId
Definition: pg_class.h:29
#define RELKIND_MATVIEW
Definition: pg_class.h:165
#define AccessShareLock
Definition: lockdefs.h:36
#define PROCARRAY_FLAGS_VACUUM
Definition: procarray.h:52
#define heap_close(r, l)
Definition: heapam.h:97
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1372
SysScanDesc systable_beginscan(Relation heapRelation, Oid indexId, bool indexOK, Snapshot snapshot, int nkeys, ScanKey key)
Definition: genam.c:328
bool ForceTransactionIdLimitUpdate(void)
Definition: varsup.c:429
HeapTuple systable_getnext(SysScanDesc sysscan)
Definition: genam.c:416
#define ObjectIdGetDatum(X)
Definition: postgres.h:513
#define ERROR
Definition: elog.h:43
#define RowExclusiveLock
Definition: lockdefs.h:38
TransactionId ReadNewTransactionId(void)
Definition: varsup.c:250
#define MultiXactIdIsValid(multi)
Definition: multixact.h:27
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
MultiXactId GetOldestMultiXactId(void)
Definition: multixact.c:2491
#define RELKIND_TOASTVALUE
Definition: pg_class.h:163
Oid MyDatabaseId
Definition: globals.c:77
Relation heap_open(Oid relationId, LOCKMODE lockmode)
Definition: heapam.c:1284
#define InvalidOid
Definition: postgres_ext.h:36
TransactionId GetOldestXmin(Relation rel, int flags)
Definition: procarray.c:1314
TransactionId MultiXactId
Definition: c.h:407
#define HeapTupleIsValid(tuple)
Definition: htup.h:77
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
Definition: multixact.c:3140
static void vac_truncate_clog(TransactionId frozenXID, MultiXactId minMulti, TransactionId lastSaneFrozenXid, MultiXactId lastSaneMinMulti)
Definition: vacuum.c:1086
FormData_pg_class * Form_pg_class
Definition: pg_class.h:95
#define SearchSysCacheCopy1(cacheId, key1)
Definition: syscache.h:165
void heap_inplace_update(Relation relation, HeapTuple tuple)
Definition: heapam.c:6195
#define elog
Definition: elog.h:219
#define TransactionIdIsNormal(xid)
Definition: transam.h:42
#define RELKIND_RELATION
Definition: pg_class.h:160
MultiXactId ReadNextMultiXactId(void)
Definition: multixact.c:721
void vac_update_relstats ( Relation  relation,
BlockNumber  num_pages,
double  num_tuples,
BlockNumber  num_all_visible_pages,
bool  hasindex,
TransactionId  frozenxid,
MultiXactId  minmulti,
bool  in_outer_xact 
)

Definition at line 785 of file vacuum.c.

References elog, ERROR, GETSTRUCT, heap_close, heap_inplace_update(), heap_open(), HeapTupleIsValid, MultiXactIdIsValid, MultiXactIdPrecedes(), NULL, ObjectIdGetDatum, RelationData::rd_rules, ReadNewTransactionId(), ReadNextMultiXactId(), RelationGetRelid, RelationRelationId, RELOID, RowExclusiveLock, SearchSysCacheCopy1, TransactionIdIsNormal, TransactionIdPrecedes(), and RelationData::trigdesc.

Referenced by do_analyze_rel(), lazy_cleanup_index(), and lazy_vacuum_rel().

791 {
792  Oid relid = RelationGetRelid(relation);
793  Relation rd;
794  HeapTuple ctup;
795  Form_pg_class pgcform;
796  bool dirty;
797 
799 
800  /* Fetch a copy of the tuple to scribble on */
802  if (!HeapTupleIsValid(ctup))
803  elog(ERROR, "pg_class entry for relid %u vanished during vacuuming",
804  relid);
805  pgcform = (Form_pg_class) GETSTRUCT(ctup);
806 
807  /* Apply statistical updates, if any, to copied tuple */
808 
809  dirty = false;
810  if (pgcform->relpages != (int32) num_pages)
811  {
812  pgcform->relpages = (int32) num_pages;
813  dirty = true;
814  }
815  if (pgcform->reltuples != (float4) num_tuples)
816  {
817  pgcform->reltuples = (float4) num_tuples;
818  dirty = true;
819  }
820  if (pgcform->relallvisible != (int32) num_all_visible_pages)
821  {
822  pgcform->relallvisible = (int32) num_all_visible_pages;
823  dirty = true;
824  }
825 
826  /* Apply DDL updates, but not inside an outer transaction (see above) */
827 
828  if (!in_outer_xact)
829  {
830  /*
831  * If we didn't find any indexes, reset relhasindex.
832  */
833  if (pgcform->relhasindex && !hasindex)
834  {
835  pgcform->relhasindex = false;
836  dirty = true;
837  }
838 
839  /*
840  * If we have discovered that there are no indexes, then there's no
841  * primary key either. This could be done more thoroughly...
842  */
843  if (pgcform->relhaspkey && !hasindex)
844  {
845  pgcform->relhaspkey = false;
846  dirty = true;
847  }
848 
849  /* We also clear relhasrules and relhastriggers if needed */
850  if (pgcform->relhasrules && relation->rd_rules == NULL)
851  {
852  pgcform->relhasrules = false;
853  dirty = true;
854  }
855  if (pgcform->relhastriggers && relation->trigdesc == NULL)
856  {
857  pgcform->relhastriggers = false;
858  dirty = true;
859  }
860  }
861 
862  /*
863  * Update relfrozenxid, unless caller passed InvalidTransactionId
864  * indicating it has no new data.
865  *
866  * Ordinarily, we don't let relfrozenxid go backwards: if things are
867  * working correctly, the only way the new frozenxid could be older would
868  * be if a previous VACUUM was done with a tighter freeze_min_age, in
869  * which case we don't want to forget the work it already did. However,
870  * if the stored relfrozenxid is "in the future", then it must be corrupt
871  * and it seems best to overwrite it with the cutoff we used this time.
872  * This should match vac_update_datfrozenxid() concerning what we consider
873  * to be "in the future".
874  */
875  if (TransactionIdIsNormal(frozenxid) &&
876  pgcform->relfrozenxid != frozenxid &&
877  (TransactionIdPrecedes(pgcform->relfrozenxid, frozenxid) ||
879  pgcform->relfrozenxid)))
880  {
881  pgcform->relfrozenxid = frozenxid;
882  dirty = true;
883  }
884 
885  /* Similarly for relminmxid */
886  if (MultiXactIdIsValid(minmulti) &&
887  pgcform->relminmxid != minmulti &&
888  (MultiXactIdPrecedes(pgcform->relminmxid, minmulti) ||
889  MultiXactIdPrecedes(ReadNextMultiXactId(), pgcform->relminmxid)))
890  {
891  pgcform->relminmxid = minmulti;
892  dirty = true;
893  }
894 
895  /* If anything changed, write out the tuple. */
896  if (dirty)
897  heap_inplace_update(rd, ctup);
898 
900 }
#define GETSTRUCT(TUP)
Definition: htup_details.h:656
#define RelationRelationId
Definition: pg_class.h:29
#define heap_close(r, l)
Definition: heapam.h:97
unsigned int Oid
Definition: postgres_ext.h:31
signed int int32
Definition: c.h:256
#define ObjectIdGetDatum(X)
Definition: postgres.h:513
#define ERROR
Definition: elog.h:43
TriggerDesc * trigdesc
Definition: rel.h:120
#define RowExclusiveLock
Definition: lockdefs.h:38
TransactionId ReadNewTransactionId(void)
Definition: varsup.c:250
#define MultiXactIdIsValid(multi)
Definition: multixact.h:27
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
float float4
Definition: c.h:380
Relation heap_open(Oid relationId, LOCKMODE lockmode)
Definition: heapam.c:1284
#define HeapTupleIsValid(tuple)
Definition: htup.h:77
#define NULL
Definition: c.h:229
RuleLock * rd_rules
Definition: rel.h:118
bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
Definition: multixact.c:3140
FormData_pg_class * Form_pg_class
Definition: pg_class.h:95
#define SearchSysCacheCopy1(cacheId, key1)
Definition: syscache.h:165
void heap_inplace_update(Relation relation, HeapTuple tuple)
Definition: heapam.c:6195
#define elog
Definition: elog.h:219
#define TransactionIdIsNormal(xid)
Definition: transam.h:42
#define RelationGetRelid(relation)
Definition: rel.h:416
MultiXactId ReadNextMultiXactId(void)
Definition: multixact.c:721
void vacuum ( int  options,
RangeVar relation,
Oid  relid,
VacuumParams params,
List va_cols,
BufferAccessStrategy  bstrategy,
bool  isTopLevel 
)

Definition at line 149 of file vacuum.c.

References ActiveSnapshotSet(), ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate(), analyze_rel(), Assert, BAS_VACUUM, CommitTransactionCommand(), cur, ereport, errcode(), errmsg(), ERROR, get_rel_oids(), GetAccessStrategy(), GetTransactionSnapshot(), IsAutoVacuumWorkerProcess(), IsInTransactionChain(), lfirst_oid, list_length(), MemoryContextDelete(), MemoryContextSwitchTo(), NULL, PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, pgstat_vacuum_stat(), PopActiveSnapshot(), PortalContext, PreventTransactionChain(), PushActiveSnapshot(), StartTransactionCommand(), vac_update_datfrozenxid(), VACOPT_ANALYZE, VACOPT_DISABLE_PAGE_SKIPPING, VACOPT_FULL, VACOPT_VACUUM, vacuum_rel(), VacuumCostActive, VacuumCostBalance, VacuumCostDelay, VacuumPageDirty, VacuumPageHit, and VacuumPageMiss.

Referenced by autovacuum_do_vac_analyze(), and ExecVacuum().

151 {
152  const char *stmttype;
153  volatile bool in_outer_xact,
154  use_own_xacts;
155  List *relations;
156  static bool in_vacuum = false;
157 
158  Assert(params != NULL);
159 
160  stmttype = (options & VACOPT_VACUUM) ? "VACUUM" : "ANALYZE";
161 
162  /*
163  * We cannot run VACUUM inside a user transaction block; if we were inside
164  * a transaction, then our commit- and start-transaction-command calls
165  * would not have the intended effect! There are numerous other subtle
166  * dependencies on this, too.
167  *
168  * ANALYZE (without VACUUM) can run either way.
169  */
170  if (options & VACOPT_VACUUM)
171  {
172  PreventTransactionChain(isTopLevel, stmttype);
173  in_outer_xact = false;
174  }
175  else
176  in_outer_xact = IsInTransactionChain(isTopLevel);
177 
178  /*
179  * Due to static variables vac_context, anl_context and vac_strategy,
180  * vacuum() is not reentrant. This matters when VACUUM FULL or ANALYZE
181  * calls a hostile index expression that itself calls ANALYZE.
182  */
183  if (in_vacuum)
184  ereport(ERROR,
185  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
186  errmsg("%s cannot be executed from VACUUM or ANALYZE",
187  stmttype)));
188 
189  /*
190  * Sanity check DISABLE_PAGE_SKIPPING option.
191  */
192  if ((options & VACOPT_FULL) != 0 &&
194  ereport(ERROR,
195  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
196  errmsg("VACUUM option DISABLE_PAGE_SKIPPING cannot be used with FULL")));
197 
198  /*
199  * Send info about dead objects to the statistics collector, unless we are
200  * in autovacuum --- autovacuum.c does this for itself.
201  */
202  if ((options & VACOPT_VACUUM) && !IsAutoVacuumWorkerProcess())
204 
205  /*
206  * Create special memory context for cross-transaction storage.
207  *
208  * Since it is a child of PortalContext, it will go away eventually even
209  * if we suffer an error; there's no need for special abort cleanup logic.
210  */
212  "Vacuum",
214 
215  /*
216  * If caller didn't give us a buffer strategy object, make one in the
217  * cross-transaction memory context.
218  */
219  if (bstrategy == NULL)
220  {
222 
223  bstrategy = GetAccessStrategy(BAS_VACUUM);
224  MemoryContextSwitchTo(old_context);
225  }
226  vac_strategy = bstrategy;
227 
228  /*
229  * Build list of relations to process, unless caller gave us one. (If we
230  * build one, we put it in vac_context for safekeeping.)
231  */
232  relations = get_rel_oids(relid, relation);
233 
234  /*
235  * Decide whether we need to start/commit our own transactions.
236  *
237  * For VACUUM (with or without ANALYZE): always do so, so that we can
238  * release locks as soon as possible. (We could possibly use the outer
239  * transaction for a one-table VACUUM, but handling TOAST tables would be
240  * problematic.)
241  *
242  * For ANALYZE (no VACUUM): if inside a transaction block, we cannot
243  * start/commit our own transactions. Also, there's no need to do so if
244  * only processing one relation. For multiple relations when not within a
245  * transaction block, and also in an autovacuum worker, use own
246  * transactions so we can release locks sooner.
247  */
248  if (options & VACOPT_VACUUM)
249  use_own_xacts = true;
250  else
251  {
254  use_own_xacts = true;
255  else if (in_outer_xact)
256  use_own_xacts = false;
257  else if (list_length(relations) > 1)
258  use_own_xacts = true;
259  else
260  use_own_xacts = false;
261  }
262 
263  /*
264  * vacuum_rel expects to be entered with no transaction active; it will
265  * start and commit its own transaction. But we are called by an SQL
266  * command, and so we are executing inside a transaction already. We
267  * commit the transaction started in PostgresMain() here, and start
268  * another one before exiting to match the commit waiting for us back in
269  * PostgresMain().
270  */
271  if (use_own_xacts)
272  {
273  Assert(!in_outer_xact);
274 
275  /* ActiveSnapshot is not set by autovacuum */
276  if (ActiveSnapshotSet())
278 
279  /* matches the StartTransaction in PostgresMain() */
281  }
282 
283  /* Turn vacuum cost accounting on or off */
284  PG_TRY();
285  {
286  ListCell *cur;
287 
288  in_vacuum = true;
290  VacuumCostBalance = 0;
291  VacuumPageHit = 0;
292  VacuumPageMiss = 0;
293  VacuumPageDirty = 0;
294 
295  /*
296  * Loop to process each selected relation.
297  */
298  foreach(cur, relations)
299  {
300  Oid relid = lfirst_oid(cur);
301 
302  if (options & VACOPT_VACUUM)
303  {
304  if (!vacuum_rel(relid, relation, options, params))
305  continue;
306  }
307 
308  if (options & VACOPT_ANALYZE)
309  {
310  /*
311  * If using separate xacts, start one for analyze. Otherwise,
312  * we can use the outer transaction.
313  */
314  if (use_own_xacts)
315  {
317  /* functions in indexes may want a snapshot set */
319  }
320 
321  analyze_rel(relid, relation, options, params,
322  va_cols, in_outer_xact, vac_strategy);
323 
324  if (use_own_xacts)
325  {
328  }
329  }
330  }
331  }
332  PG_CATCH();
333  {
334  in_vacuum = false;
335  VacuumCostActive = false;
336  PG_RE_THROW();
337  }
338  PG_END_TRY();
339 
340  in_vacuum = false;
341  VacuumCostActive = false;
342 
343  /*
344  * Finish up processing.
345  */
346  if (use_own_xacts)
347  {
348  /* here, we are not in a transaction */
349 
350  /*
351  * This matches the CommitTransaction waiting for us in
352  * PostgresMain().
353  */
355  }
356 
357  if ((options & VACOPT_VACUUM) && !IsAutoVacuumWorkerProcess())
358  {
359  /*
360  * Update pg_database.datfrozenxid, and truncate pg_xact if possible.
361  * (autovacuum.c does this for itself.)
362  */
364  }
365 
366  /*
367  * Clean up working storage --- note we must do this after
368  * StartTransactionCommand, else we might be trying to delete the active
369  * context!
370  */
372  vac_context = NULL;
373 }
BufferAccessStrategy GetAccessStrategy(BufferAccessStrategyType btype)
Definition: freelist.c:525
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:200
int VacuumCostBalance
Definition: globals.c:139
void vac_update_datfrozenxid(void)
Definition: vacuum.c:922
int VacuumPageHit
Definition: globals.c:135
void CommitTransactionCommand(void)
Definition: xact.c:2748
void analyze_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params, List *va_cols, bool in_outer_xact, BufferAccessStrategy bstrategy)
Definition: analyze.c:111
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:109
static BufferAccessStrategy vac_strategy
Definition: vacuum.c:66
struct cursor * cur
Definition: ecpg.c:28
int errcode(int sqlerrcode)
Definition: elog.c:575
void PopActiveSnapshot(void)
Definition: snapmgr.c:812
unsigned int Oid
Definition: postgres_ext.h:31
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:304
static List * get_rel_oids(Oid relid, const RangeVar *vacrel)
Definition: vacuum.c:382
MemoryContext PortalContext
Definition: mcxt.c:52
#define ERROR
Definition: elog.h:43
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:165
void PushActiveSnapshot(Snapshot snap)
Definition: snapmgr.c:733
static MemoryContext vac_context
Definition: vacuum.c:65
bool ActiveSnapshotSet(void)
Definition: snapmgr.c:851
bool IsAutoVacuumWorkerProcess(void)
Definition: autovacuum.c:3361
#define ereport(elevel, rest)
Definition: elog.h:122
void pgstat_vacuum_stat(void)
Definition: pgstat.c:1022
int VacuumPageDirty
Definition: globals.c:137
MemoryContext AllocSetContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: aset.c:322
int VacuumCostDelay
Definition: globals.c:133
#define PG_CATCH()
Definition: elog.h:293
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static bool vacuum_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params)
Definition: vacuum.c:1224
void StartTransactionCommand(void)
Definition: xact.c:2678
static int list_length(const List *l)
Definition: pg_list.h:89
#define PG_RE_THROW()
Definition: elog.h:314
int errmsg(const char *fmt,...)
Definition: elog.c:797
bool IsInTransactionChain(bool isTopLevel)
Definition: xact.c:3271
int VacuumPageMiss
Definition: globals.c:136
#define PG_TRY()
Definition: elog.h:284
Definition: pg_list.h:45
#define PG_END_TRY()
Definition: elog.h:300
#define lfirst_oid(lc)
Definition: pg_list.h:108
void PreventTransactionChain(bool isTopLevel, const char *stmtType)
Definition: xact.c:3155
bool VacuumCostActive
Definition: globals.c:140
void vacuum_delay_point ( void  )

Definition at line 1560 of file vacuum.c.

References AutoVacuumUpdateDelay(), CHECK_FOR_INTERRUPTS, InterruptPending, pg_usleep(), VacuumCostActive, VacuumCostBalance, VacuumCostDelay, and VacuumCostLimit.

Referenced by acquire_sample_rows(), blbulkdelete(), blvacuumcleanup(), btvacuumpage(), compute_array_stats(), compute_distinct_stats(), compute_index_stats(), compute_range_stats(), compute_scalar_stats(), compute_trivial_stats(), compute_tsvector_stats(), file_acquire_sample_rows(), ginbulkdelete(), ginInsertCleanup(), ginvacuumcleanup(), ginVacuumPostingTreeLeaves(), gistbulkdelete(), gistvacuumcleanup(), hashbucketcleanup(), lazy_scan_heap(), lazy_vacuum_heap(), spgprocesspending(), and spgvacuumpage().

1561 {
1562  /* Always check for interrupts */
1564 
1565  /* Nap if appropriate */
1568  {
1569  int msec;
1570 
1572  if (msec > VacuumCostDelay * 4)
1573  msec = VacuumCostDelay * 4;
1574 
1575  pg_usleep(msec * 1000L);
1576 
1577  VacuumCostBalance = 0;
1578 
1579  /* update balance values for workers */
1581 
1582  /* Might have gotten an interrupt while sleeping */
1584  }
1585 }
int VacuumCostBalance
Definition: globals.c:139
void pg_usleep(long microsec)
Definition: signal.c:53
int VacuumCostLimit
Definition: globals.c:132
int VacuumCostDelay
Definition: globals.c:133
volatile bool InterruptPending
Definition: globals.c:29
void AutoVacuumUpdateDelay(void)
Definition: autovacuum.c:1780
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:98
bool VacuumCostActive
Definition: globals.c:140
static bool vacuum_rel ( Oid  relid,
RangeVar relation,
int  options,
VacuumParams params 
)
static

Definition at line 1224 of file vacuum.c.

References AccessExclusiveLock, Assert, AtEOXact_GUC(), CHECK_FOR_INTERRUPTS, cluster_rel(), CommitTransactionCommand(), ConditionalLockRelationOid(), ereport, errcode(), errmsg(), GetTransactionSnapshot(), GetUserId(), GetUserIdAndSecContext(), InvalidOid, VacuumParams::is_wraparound, IsAutoVacuumWorkerProcess(), lazy_vacuum_rel(), LockRelationIdForSession(), LockInfoData::lockRelId, LOG, VacuumParams::log_min_duration, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyDatabaseId, MyPgXact, NewGUCNestLevel(), NoLock, NULL, PG_CATALOG_NAMESPACE, pg_class_ownercheck(), pg_database_ownercheck(), PopActiveSnapshot(), PROC_IN_VACUUM, PROC_VACUUM_FOR_WRAPAROUND, PushActiveSnapshot(), RelationData::rd_lockInfo, RelationData::rd_rel, relation_close(), RELATION_IS_OTHER_TEMP, RelationGetRelationName, RelationGetRelid, RELKIND_MATVIEW, RELKIND_PARTITIONED_TABLE, RELKIND_RELATION, RELKIND_TOASTVALUE, RangeVar::relname, SECURITY_RESTRICTED_OPERATION, SetUserIdAndSecContext(), ShareUpdateExclusiveLock, StartTransactionCommand(), try_relation_open(), UnlockRelationIdForSession(), VACOPT_FULL, VACOPT_NOWAIT, VACOPT_SKIPTOAST, VACOPT_VERBOSE, PGXACT::vacuumFlags, and WARNING.

Referenced by vacuum().

1225 {
1226  LOCKMODE lmode;
1227  Relation onerel;
1228  LockRelId onerelid;
1229  Oid toast_relid;
1230  Oid save_userid;
1231  int save_sec_context;
1232  int save_nestlevel;
1233 
1234  Assert(params != NULL);
1235 
1236  /* Begin a transaction for vacuuming this relation */
1238 
1239  /*
1240  * Functions in indexes may want a snapshot set. Also, setting a snapshot
1241  * ensures that RecentGlobalXmin is kept truly recent.
1242  */
1244 
1245  if (!(options & VACOPT_FULL))
1246  {
1247  /*
1248  * In lazy vacuum, we can set the PROC_IN_VACUUM flag, which lets
1249  * other concurrent VACUUMs know that they can ignore this one while
1250  * determining their OldestXmin. (The reason we don't set it during a
1251  * full VACUUM is exactly that we may have to run user-defined
1252  * functions for functional indexes, and we want to make sure that if
1253  * they use the snapshot set above, any tuples it requires can't get
1254  * removed from other tables. An index function that depends on the
1255  * contents of other tables is arguably broken, but we won't break it
1256  * here by violating transaction semantics.)
1257  *
1258  * We also set the VACUUM_FOR_WRAPAROUND flag, which is passed down by
1259  * autovacuum; it's used to avoid canceling a vacuum that was invoked
1260  * in an emergency.
1261  *
1262  * Note: these flags remain set until CommitTransaction or
1263  * AbortTransaction. We don't want to clear them until we reset
1264  * MyPgXact->xid/xmin, else OldestXmin might appear to go backwards,
1265  * which is probably Not Good.
1266  */
1267  LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
1269  if (params->is_wraparound)
1271  LWLockRelease(ProcArrayLock);
1272  }
1273 
1274  /*
1275  * Check for user-requested abort. Note we want this to be inside a
1276  * transaction, so xact.c doesn't issue useless WARNING.
1277  */
1279 
1280  /*
1281  * Determine the type of lock we want --- hard exclusive lock for a FULL
1282  * vacuum, but just ShareUpdateExclusiveLock for concurrent vacuum. Either
1283  * way, we can be sure that no other backend is vacuuming the same table.
1284  */
1286 
1287  /*
1288  * Open the relation and get the appropriate lock on it.
1289  *
1290  * There's a race condition here: the rel may have gone away since the
1291  * last time we saw it. If so, we don't need to vacuum it.
1292  *
1293  * If we've been asked not to wait for the relation lock, acquire it first
1294  * in non-blocking mode, before calling try_relation_open().
1295  */
1296  if (!(options & VACOPT_NOWAIT))
1297  onerel = try_relation_open(relid, lmode);
1298  else if (ConditionalLockRelationOid(relid, lmode))
1299  onerel = try_relation_open(relid, NoLock);
1300  else
1301  {
1302  onerel = NULL;
1303  if (IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
1304  ereport(LOG,
1305  (errcode(ERRCODE_LOCK_NOT_AVAILABLE),
1306  errmsg("skipping vacuum of \"%s\" --- lock not available",
1307  relation->relname)));
1308  }
1309 
1310  if (!onerel)
1311  {
1314  return false;
1315  }
1316 
1317  /*
1318  * Check permissions.
1319  *
1320  * We allow the user to vacuum a table if he is superuser, the table
1321  * owner, or the database owner (but in the latter case, only if it's not
1322  * a shared relation). pg_class_ownercheck includes the superuser case.
1323  *
1324  * Note we choose to treat permissions failure as a WARNING and keep
1325  * trying to vacuum the rest of the DB --- is this appropriate?
1326  */
1327  if (!(pg_class_ownercheck(RelationGetRelid(onerel), GetUserId()) ||
1328  (pg_database_ownercheck(MyDatabaseId, GetUserId()) && !onerel->rd_rel->relisshared)))
1329  {
1330  if (onerel->rd_rel->relisshared)
1331  ereport(WARNING,
1332  (errmsg("skipping \"%s\" --- only superuser can vacuum it",
1333  RelationGetRelationName(onerel))));
1334  else if (onerel->rd_rel->relnamespace == PG_CATALOG_NAMESPACE)
1335  ereport(WARNING,
1336  (errmsg("skipping \"%s\" --- only superuser or database owner can vacuum it",
1337  RelationGetRelationName(onerel))));
1338  else
1339  ereport(WARNING,
1340  (errmsg("skipping \"%s\" --- only table or database owner can vacuum it",
1341  RelationGetRelationName(onerel))));
1342  relation_close(onerel, lmode);
1345  return false;
1346  }
1347 
1348  /*
1349  * Check that it's a vacuumable relation; we used to do this in
1350  * get_rel_oids() but seems safer to check after we've locked the
1351  * relation.
1352  */
1353  if (onerel->rd_rel->relkind != RELKIND_RELATION &&
1354  onerel->rd_rel->relkind != RELKIND_MATVIEW &&
1355  onerel->rd_rel->relkind != RELKIND_TOASTVALUE &&
1356  onerel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
1357  {
1358  ereport(WARNING,
1359  (errmsg("skipping \"%s\" --- cannot vacuum non-tables or special system tables",
1360  RelationGetRelationName(onerel))));
1361  relation_close(onerel, lmode);
1364  return false;
1365  }
1366 
1367  /*
1368  * Silently ignore tables that are temp tables of other backends ---
1369  * trying to vacuum these will lead to great unhappiness, since their
1370  * contents are probably not up-to-date on disk. (We don't throw a
1371  * warning here; it would just lead to chatter during a database-wide
1372  * VACUUM.)
1373  */
1374  if (RELATION_IS_OTHER_TEMP(onerel))
1375  {
1376  relation_close(onerel, lmode);
1379  return false;
1380  }
1381 
1382  /*
1383  * Ignore partitioned tables as there is no work to be done. Since we
1384  * release the lock here, it's possible that any partitions added from
1385  * this point on will not get processed, but that seems harmless.
1386  */
1387  if (onerel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
1388  {
1389  relation_close(onerel, lmode);
1392 
1393  /* It's OK for other commands to look at this table */
1394  return true;
1395  }
1396 
1397  /*
1398  * Get a session-level lock too. This will protect our access to the
1399  * relation across multiple transactions, so that we can vacuum the
1400  * relation's TOAST table (if any) secure in the knowledge that no one is
1401  * deleting the parent relation.
1402  *
1403  * NOTE: this cannot block, even if someone else is waiting for access,
1404  * because the lock manager knows that both lock requests are from the
1405  * same process.
1406  */
1407  onerelid = onerel->rd_lockInfo.lockRelId;
1408  LockRelationIdForSession(&onerelid, lmode);
1409 
1410  /*
1411  * Remember the relation's TOAST relation for later, if the caller asked
1412  * us to process it. In VACUUM FULL, though, the toast table is
1413  * automatically rebuilt by cluster_rel so we shouldn't recurse to it.
1414  */
1415  if (!(options & VACOPT_SKIPTOAST) && !(options & VACOPT_FULL))
1416  toast_relid = onerel->rd_rel->reltoastrelid;
1417  else
1418  toast_relid = InvalidOid;
1419 
1420  /*
1421  * Switch to the table owner's userid, so that any index functions are run
1422  * as that user. Also lock down security-restricted operations and
1423  * arrange to make GUC variable changes local to this command. (This is
1424  * unnecessary, but harmless, for lazy VACUUM.)
1425  */
1426  GetUserIdAndSecContext(&save_userid, &save_sec_context);
1427  SetUserIdAndSecContext(onerel->rd_rel->relowner,
1428  save_sec_context | SECURITY_RESTRICTED_OPERATION);
1429  save_nestlevel = NewGUCNestLevel();
1430 
1431  /*
1432  * Do the actual work --- either FULL or "lazy" vacuum
1433  */
1434  if (options & VACOPT_FULL)
1435  {
1436  /* close relation before vacuuming, but hold lock until commit */
1437  relation_close(onerel, NoLock);
1438  onerel = NULL;
1439 
1440  /* VACUUM FULL is now a variant of CLUSTER; see cluster.c */
1441  cluster_rel(relid, InvalidOid, false,
1442  (options & VACOPT_VERBOSE) != 0);
1443  }
1444  else
1445  lazy_vacuum_rel(onerel, options, params, vac_strategy);
1446 
1447  /* Roll back any GUC changes executed by index functions */
1448  AtEOXact_GUC(false, save_nestlevel);
1449 
1450  /* Restore userid and security context */
1451  SetUserIdAndSecContext(save_userid, save_sec_context);
1452 
1453  /* all done with this class, but hold lock until commit */
1454  if (onerel)
1455  relation_close(onerel, NoLock);
1456 
1457  /*
1458  * Complete the transaction and free all temporary memory used.
1459  */
1462 
1463  /*
1464  * If the relation has a secondary toast rel, vacuum that too while we
1465  * still hold the session lock on the master table. Note however that
1466  * "analyze" will not get done on the toast table. This is good, because
1467  * the toaster always uses hardcoded index access and statistics are
1468  * totally unimportant for toast relations.
1469  */
1470  if (toast_relid != InvalidOid)
1471  vacuum_rel(toast_relid, relation, options, params);
1472 
1473  /*
1474  * Now release the session-level lock on the master table.
1475  */
1476  UnlockRelationIdForSession(&onerelid, lmode);
1477 
1478  /* Report that we really did it. */
1479  return true;
1480 }
bool ConditionalLockRelationOid(Oid relid, LOCKMODE lockmode)
Definition: lmgr.c:138
LockRelId lockRelId
Definition: rel.h:44
#define SECURITY_RESTRICTED_OPERATION
Definition: miscadmin.h:295
void SetUserIdAndSecContext(Oid userid, int sec_context)
Definition: miscinit.c:396
int LOCKMODE
Definition: lockdefs.h:26
Relation try_relation_open(Oid relationId, LOCKMODE lockmode)
Definition: heapam.c:1147
Oid GetUserId(void)
Definition: miscinit.c:284
void CommitTransactionCommand(void)
Definition: xact.c:2748
#define PROC_VACUUM_FOR_WRAPAROUND
Definition: proc.h:55
#define RELKIND_MATVIEW
Definition: pg_class.h:165
static BufferAccessStrategy vac_strategy
Definition: vacuum.c:66
int errcode(int sqlerrcode)
Definition: elog.c:575
void relation_close(Relation relation, LOCKMODE lockmode)
Definition: heapam.c:1260
void PopActiveSnapshot(void)
Definition: snapmgr.c:812
#define LOG
Definition: elog.h:26
Form_pg_class rd_rel
Definition: rel.h:114
unsigned int Oid
Definition: postgres_ext.h:31
Snapshot GetTransactionSnapshot(void)
Definition: snapmgr.c:304
PGXACT * MyPgXact
Definition: proc.c:68
uint8 vacuumFlags
Definition: proc.h:218
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
char * relname
Definition: primnodes.h:68
#define PROC_IN_VACUUM
Definition: proc.h:53
void UnlockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode)
Definition: lmgr.c:312
void cluster_rel(Oid tableOid, Oid indexOid, bool recheck, bool verbose)
Definition: cluster.c:260
Definition: rel.h:36
void LockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode)
Definition: lmgr.c:299
void lazy_vacuum_rel(Relation onerel, int options, VacuumParams *params, BufferAccessStrategy bstrategy)
Definition: vacuumlazy.c:182
bool is_wraparound
Definition: vacuum.h:144
#define NoLock
Definition: lockdefs.h:34
LockInfoData rd_lockInfo
Definition: rel.h:117
void PushActiveSnapshot(Snapshot snap)
Definition: snapmgr.c:733
void GetUserIdAndSecContext(Oid *userid, int *sec_context)
Definition: miscinit.c:389
void AtEOXact_GUC(bool isCommit, int nestLevel)
Definition: guc.c:5079
#define RelationGetRelationName(relation)
Definition: rel.h:436
#define PG_CATALOG_NAMESPACE
Definition: pg_namespace.h:71
bool IsAutoVacuumWorkerProcess(void)
Definition: autovacuum.c:3361
#define ereport(elevel, rest)
Definition: elog.h:122
bool pg_database_ownercheck(Oid db_oid, Oid roleid)
Definition: aclchk.c:4964
#define WARNING
Definition: elog.h:40
#define RELKIND_PARTITIONED_TABLE
Definition: pg_class.h:168
#define RELKIND_TOASTVALUE
Definition: pg_class.h:163
Oid MyDatabaseId
Definition: globals.c:77
#define InvalidOid
Definition: postgres_ext.h:36
#define ShareUpdateExclusiveLock
Definition: lockdefs.h:39
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static bool vacuum_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params)
Definition: vacuum.c:1224
#define RELATION_IS_OTHER_TEMP(relation)
Definition: rel.h:533
bool pg_class_ownercheck(Oid class_oid, Oid roleid)
Definition: aclchk.c:4546
void StartTransactionCommand(void)
Definition: xact.c:2678
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
int log_min_duration
Definition: vacuum.h:145
#define AccessExclusiveLock
Definition: lockdefs.h:45
int NewGUCNestLevel(void)
Definition: guc.c:5065
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:98
#define RELKIND_RELATION
Definition: pg_class.h:160
#define RelationGetRelid(relation)
Definition: rel.h:416
void vacuum_set_xid_limits ( Relation  rel,
int  freeze_min_age,
int  freeze_table_age,
int  multixact_freeze_min_age,
int  multixact_freeze_table_age,
TransactionId oldestXmin,
TransactionId freezeLimit,
TransactionId xidFullScanLimit,
MultiXactId multiXactCutoff,
MultiXactId mxactFullScanLimit 
)

Definition at line 501 of file vacuum.c.

References Assert, autovacuum_freeze_max_age, ereport, errhint(), errmsg(), FirstMultiXactId, FirstNormalTransactionId, GetOldestMultiXactId(), GetOldestXmin(), Min, MultiXactIdPrecedes(), MultiXactMemberFreezeThreshold(), NULL, PROCARRAY_FLAGS_VACUUM, ReadNewTransactionId(), ReadNextMultiXactId(), TransactionIdIsNormal, TransactionIdLimitedForOldSnapshots(), TransactionIdPrecedes(), vacuum_freeze_min_age, vacuum_freeze_table_age, vacuum_multixact_freeze_min_age, vacuum_multixact_freeze_table_age, and WARNING.

Referenced by copy_heap_data(), and lazy_vacuum_rel().

511 {
512  int freezemin;
513  int mxid_freezemin;
514  int effective_multixact_freeze_max_age;
515  TransactionId limit;
516  TransactionId safeLimit;
517  MultiXactId mxactLimit;
518  MultiXactId safeMxactLimit;
519 
520  /*
521  * We can always ignore processes running lazy vacuum. This is because we
522  * use these values only for deciding which tuples we must keep in the
523  * tables. Since lazy vacuum doesn't write its XID anywhere, it's safe to
524  * ignore it. In theory it could be problematic to ignore lazy vacuums in
525  * a full vacuum, but keep in mind that only one vacuum process can be
526  * working on a particular table at any time, and that each vacuum is
527  * always an independent transaction.
528  */
529  *oldestXmin =
531 
532  Assert(TransactionIdIsNormal(*oldestXmin));
533 
534  /*
535  * Determine the minimum freeze age to use: as specified by the caller, or
536  * vacuum_freeze_min_age, but in any case not more than half
537  * autovacuum_freeze_max_age, so that autovacuums to prevent XID
538  * wraparound won't occur too frequently.
539  */
540  freezemin = freeze_min_age;
541  if (freezemin < 0)
542  freezemin = vacuum_freeze_min_age;
543  freezemin = Min(freezemin, autovacuum_freeze_max_age / 2);
544  Assert(freezemin >= 0);
545 
546  /*
547  * Compute the cutoff XID, being careful not to generate a "permanent" XID
548  */
549  limit = *oldestXmin - freezemin;
550  if (!TransactionIdIsNormal(limit))
551  limit = FirstNormalTransactionId;
552 
553  /*
554  * If oldestXmin is very far back (in practice, more than
555  * autovacuum_freeze_max_age / 2 XIDs old), complain and force a minimum
556  * freeze age of zero.
557  */
559  if (!TransactionIdIsNormal(safeLimit))
560  safeLimit = FirstNormalTransactionId;
561 
562  if (TransactionIdPrecedes(limit, safeLimit))
563  {
565  (errmsg("oldest xmin is far in the past"),
566  errhint("Close open transactions soon to avoid wraparound problems.")));
567  limit = *oldestXmin;
568  }
569 
570  *freezeLimit = limit;
571 
572  /*
573  * Compute the multixact age for which freezing is urgent. This is
574  * normally autovacuum_multixact_freeze_max_age, but may be less if we are
575  * short of multixact member space.
576  */
577  effective_multixact_freeze_max_age = MultiXactMemberFreezeThreshold();
578 
579  /*
580  * Determine the minimum multixact freeze age to use: as specified by
581  * caller, or vacuum_multixact_freeze_min_age, but in any case not more
582  * than half effective_multixact_freeze_max_age, so that autovacuums to
583  * prevent MultiXact wraparound won't occur too frequently.
584  */
585  mxid_freezemin = multixact_freeze_min_age;
586  if (mxid_freezemin < 0)
587  mxid_freezemin = vacuum_multixact_freeze_min_age;
588  mxid_freezemin = Min(mxid_freezemin,
589  effective_multixact_freeze_max_age / 2);
590  Assert(mxid_freezemin >= 0);
591 
592  /* compute the cutoff multi, being careful to generate a valid value */
593  mxactLimit = GetOldestMultiXactId() - mxid_freezemin;
594  if (mxactLimit < FirstMultiXactId)
595  mxactLimit = FirstMultiXactId;
596 
597  safeMxactLimit =
598  ReadNextMultiXactId() - effective_multixact_freeze_max_age;
599  if (safeMxactLimit < FirstMultiXactId)
600  safeMxactLimit = FirstMultiXactId;
601 
602  if (MultiXactIdPrecedes(mxactLimit, safeMxactLimit))
603  {
605  (errmsg("oldest multixact is far in the past"),
606  errhint("Close open transactions with multixacts soon to avoid wraparound problems.")));
607  mxactLimit = safeMxactLimit;
608  }
609 
610  *multiXactCutoff = mxactLimit;
611 
612  if (xidFullScanLimit != NULL)
613  {
614  int freezetable;
615 
616  Assert(mxactFullScanLimit != NULL);
617 
618  /*
619  * Determine the table freeze age to use: as specified by the caller,
620  * or vacuum_freeze_table_age, but in any case not more than
621  * autovacuum_freeze_max_age * 0.95, so that if you have e.g nightly
622  * VACUUM schedule, the nightly VACUUM gets a chance to freeze tuples
623  * before anti-wraparound autovacuum is launched.
624  */
625  freezetable = freeze_table_age;
626  if (freezetable < 0)
627  freezetable = vacuum_freeze_table_age;
628  freezetable = Min(freezetable, autovacuum_freeze_max_age * 0.95);
629  Assert(freezetable >= 0);
630 
631  /*
632  * Compute XID limit causing a full-table vacuum, being careful not to
633  * generate a "permanent" XID.
634  */
635  limit = ReadNewTransactionId() - freezetable;
636  if (!TransactionIdIsNormal(limit))
637  limit = FirstNormalTransactionId;
638 
639  *xidFullScanLimit = limit;
640 
641  /*
642  * Similar to the above, determine the table freeze age to use for
643  * multixacts: as specified by the caller, or
644  * vacuum_multixact_freeze_table_age, but in any case not more than
645  * autovacuum_multixact_freeze_table_age * 0.95, so that if you have
646  * e.g. nightly VACUUM schedule, the nightly VACUUM gets a chance to
647  * freeze multixacts before anti-wraparound autovacuum is launched.
648  */
649  freezetable = multixact_freeze_table_age;
650  if (freezetable < 0)
651  freezetable = vacuum_multixact_freeze_table_age;
652  freezetable = Min(freezetable,
653  effective_multixact_freeze_max_age * 0.95);
654  Assert(freezetable >= 0);
655 
656  /*
657  * Compute MultiXact limit causing a full-table vacuum, being careful
658  * to generate a valid MultiXact value.
659  */
660  mxactLimit = ReadNextMultiXactId() - freezetable;
661  if (mxactLimit < FirstMultiXactId)
662  mxactLimit = FirstMultiXactId;
663 
664  *mxactFullScanLimit = mxactLimit;
665  }
666  else
667  {
668  Assert(mxactFullScanLimit == NULL);
669  }
670 }
int errhint(const char *fmt,...)
Definition: elog.c:987
int vacuum_multixact_freeze_table_age
Definition: vacuum.c:61
uint32 TransactionId
Definition: c.h:397
#define Min(x, y)
Definition: c.h:806
TransactionId TransactionIdLimitedForOldSnapshots(TransactionId recentXmin, Relation relation)
Definition: snapmgr.c:1735
#define PROCARRAY_FLAGS_VACUUM
Definition: procarray.h:52
#define FirstNormalTransactionId
Definition: transam.h:34
int autovacuum_freeze_max_age
Definition: autovacuum.c:120
int vacuum_multixact_freeze_min_age
Definition: vacuum.c:60
TransactionId ReadNewTransactionId(void)
Definition: varsup.c:250
#define FirstMultiXactId
Definition: multixact.h:24
#define ereport(elevel, rest)
Definition: elog.h:122
int MultiXactMemberFreezeThreshold(void)
Definition: multixact.c:2817
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
#define WARNING
Definition: elog.h:40
MultiXactId GetOldestMultiXactId(void)
Definition: multixact.c:2491
TransactionId GetOldestXmin(Relation rel, int flags)
Definition: procarray.c:1314
TransactionId MultiXactId
Definition: c.h:407
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
int vacuum_freeze_min_age
Definition: vacuum.c:58
bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2)
Definition: multixact.c:3140
int vacuum_freeze_table_age
Definition: vacuum.c:59
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define TransactionIdIsNormal(xid)
Definition: transam.h:42
MultiXactId ReadNextMultiXactId(void)
Definition: multixact.c:721

Variable Documentation

MemoryContext vac_context = NULL
static

Definition at line 65 of file vacuum.c.

BufferAccessStrategy vac_strategy
static

Definition at line 66 of file vacuum.c.

int vacuum_freeze_min_age

Definition at line 58 of file vacuum.c.

Referenced by do_autovacuum(), and vacuum_set_xid_limits().

int vacuum_freeze_table_age

Definition at line 59 of file vacuum.c.

Referenced by do_autovacuum(), and vacuum_set_xid_limits().

int vacuum_multixact_freeze_min_age

Definition at line 60 of file vacuum.c.

Referenced by do_autovacuum(), and vacuum_set_xid_limits().

int vacuum_multixact_freeze_table_age

Definition at line 61 of file vacuum.c.

Referenced by do_autovacuum(), and vacuum_set_xid_limits().