*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.375 2008/06/05 15:47:32 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.376 2008/08/13 00:07:50 alvherre Exp $
*
*-------------------------------------------------------------------------
*/
static List *get_rel_oids(Oid relid, const RangeVar *vacrel,
const char *stmttype);
static void vac_truncate_clog(TransactionId frozenXID);
-static void vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind,
- bool for_wraparound);
+static void vacuum_rel(Oid relid, VacuumStmt *vacstmt, bool do_toast,
+ bool for_wraparound);
static void full_vacuum_rel(Relation onerel, VacuumStmt *vacstmt);
static void scan_heap(VRelStats *vacrelstats, Relation onerel,
VacPageList vacuum_pages, VacPageList fraged_pages);
* OID to be processed, and vacstmt->relation is ignored. (The non-invalid
* case is currently only used by autovacuum.)
*
+ * do_toast is passed as FALSE by autovacuum, because it processes TOAST
+ * tables separately.
+ *
* for_wraparound is used by autovacuum to let us know when it's forcing
* a vacuum for wraparound, which should not be auto-cancelled.
*
* at transaction commit.
*/
void
-vacuum(VacuumStmt *vacstmt, Oid relid,
+vacuum(VacuumStmt *vacstmt, Oid relid, bool do_toast,
BufferAccessStrategy bstrategy, bool for_wraparound, bool isTopLevel)
{
const char *stmttype = vacstmt->vacuum ? "VACUUM" : "ANALYZE";
Oid relid = lfirst_oid(cur);
if (vacstmt->vacuum)
- vacuum_rel(relid, vacstmt, RELKIND_RELATION, for_wraparound);
+ vacuum_rel(relid, vacstmt, do_toast, for_wraparound);
if (vacstmt->analyze)
{
* At entry and exit, we are not inside a transaction.
*/
static void
-vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind,
- bool for_wraparound)
+vacuum_rel(Oid relid, VacuumStmt *vacstmt, bool do_toast, bool for_wraparound)
{
LOCKMODE lmode;
Relation onerel;
* by autovacuum; it's used to avoid cancelling a vacuum that was
* invoked in an emergency.
*
- * Note: this flag remains set until CommitTransaction or
- * AbortTransaction. We don't want to clear it until we reset
+ * Note: these flags remain set until CommitTransaction or
+ * AbortTransaction. We don't want to clear them until we reset
* MyProc->xid/xmin, else OldestXmin might appear to go backwards,
* which is probably Not Good.
*/
}
/*
- * Check that it's a plain table; we used to do this in get_rel_oids() but
- * seems safer to check after we've locked the relation.
+ * Check that it's a vacuumable table; we used to do this in get_rel_oids()
+ * but seems safer to check after we've locked the relation.
*/
- if (onerel->rd_rel->relkind != expected_relkind)
+ if (onerel->rd_rel->relkind != RELKIND_RELATION &&
+ onerel->rd_rel->relkind != RELKIND_TOASTVALUE)
{
ereport(WARNING,
(errmsg("skipping \"%s\" --- cannot vacuum indexes, views, or special system tables",
LockRelationIdForSession(&onerelid, lmode);
/*
- * Remember the relation's TOAST relation for later
+ * Remember the relation's TOAST relation for later, if the caller asked
+ * us to process it.
*/
- toast_relid = onerel->rd_rel->reltoastrelid;
+ if (do_toast)
+ toast_relid = onerel->rd_rel->reltoastrelid;
+ else
+ toast_relid = InvalidOid;
/*
* Switch to the table owner's userid, so that any index functions are
* totally unimportant for toast relations.
*/
if (toast_relid != InvalidOid)
- vacuum_rel(toast_relid, vacstmt, RELKIND_TOASTVALUE, for_wraparound);
+ vacuum_rel(toast_relid, vacstmt, false, for_wraparound);
/*
* Now release the session-level lock on the master table.
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.83 2008/07/23 20:20:10 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.84 2008/08/13 00:07:50 alvherre Exp $
*
*-------------------------------------------------------------------------
*/
#include "storage/procarray.h"
#include "storage/sinvaladt.h"
#include "tcop/tcopprot.h"
+#include "utils/dynahash.h"
#include "utils/flatfiles.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
/* struct to keep track of tables to vacuum and/or analyze, in 1st pass */
typedef struct av_relation
{
+ Oid ar_toastrelid; /* hash key - must be first */
Oid ar_relid;
- Oid ar_toastrelid;
} av_relation;
/* struct to keep track of tables to vacuum and/or analyze, after rechecking */
static void do_autovacuum(void);
static void FreeWorkerInfo(int code, Datum arg);
-static autovac_table *table_recheck_autovac(Oid relid);
+static autovac_table *table_recheck_autovac(Oid relid, HTAB *table_toast_map);
static void relation_needs_vacanalyze(Oid relid, Form_pg_autovacuum avForm,
Form_pg_class classForm,
PgStat_StatTabEntry *tabentry, bool *dovacuum,
static void autovacuum_do_vac_analyze(autovac_table *tab,
BufferAccessStrategy bstrategy);
-static HeapTuple get_pg_autovacuum_tuple_relid(Relation avRel, Oid relid);
+static HeapTuple get_pg_autovacuum_tuple_relid(Relation avRel, Oid relid,
+ HTAB *table_toast_map);
static PgStat_StatTabEntry *get_pgstat_tabentry_relid(Oid relid, bool isshared,
PgStat_StatDBEntry *shared,
PgStat_StatDBEntry *dbentry);
HeapScanDesc relScan;
Form_pg_database dbForm;
List *table_oids = NIL;
- List *toast_oids = NIL;
- List *table_toast_list = NIL;
+ HASHCTL ctl;
+ HTAB *table_toast_map;
ListCell *volatile cell;
PgStat_StatDBEntry *shared;
PgStat_StatDBEntry *dbentry;
BufferAccessStrategy bstrategy;
+ ScanKeyData key;
/*
* StartTransactionCommand and CommitTransactionCommand will automatically
classRel = heap_open(RelationRelationId, AccessShareLock);
avRel = heap_open(AutovacuumRelationId, AccessShareLock);
+ /* create hash table for toast <-> main relid mapping */
+ MemSet(&ctl, 0, sizeof(ctl));
+ ctl.keysize = sizeof(Oid);
+ ctl.entrysize = sizeof(Oid) * 2;
+ ctl.hash = oid_hash;
+
+ table_toast_map = hash_create("TOAST to main relid map",
+ 100,
+ &ctl,
+ HASH_ELEM | HASH_FUNCTION);
+
/*
- * Scan pg_class and determine which tables to vacuum.
+ * Scan pg_class to determine which tables to vacuum.
*
- * The stats subsystem collects stats for toast tables independently of
- * the stats for their parent tables. We need to check those stats since
- * in cases with short, wide tables there might be proportionally much
- * more activity in the toast table than in its parent.
+ * We do this in two passes: on the first one we collect the list of
+ * plain relations, and on the second one we collect TOAST tables.
+ * The reason for doing the second pass is that during it we want to use
+ * the main relation's pg_autovacuum entry if the TOAST table does not have
+ * any, and we cannot obtain it unless we know beforehand what's the main
+ * table OID.
*
- * Since we can only issue VACUUM against the parent table, we need to
- * transpose a decision to vacuum a toast table into a decision to vacuum
- * its parent. There's no point in considering ANALYZE on a toast table,
- * either. To support this, we keep a list of OIDs of toast tables that
- * need vacuuming alongside the list of regular tables. Regular tables
- * will be entered into the table list even if they appear not to need
- * vacuuming; we go back and re-mark them after finding all the vacuumable
- * toast tables.
+ * We need to check TOAST tables separately because in cases with short,
+ * wide tables there might be proportionally much more activity in the
+ * TOAST table than in its parent.
*/
- relScan = heap_beginscan(classRel, SnapshotNow, 0, NULL);
+ ScanKeyInit(&key,
+ Anum_pg_class_relkind,
+ BTEqualStrategyNumber, F_CHAREQ,
+ CharGetDatum(RELKIND_RELATION));
+
+ relScan = heap_beginscan(classRel, SnapshotNow, 1, &key);
+ /*
+ * On the first pass, we collect main tables to vacuum, and also the
+ * main table relid to TOAST relid mapping.
+ */
while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
{
Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
bool wraparound;
int backendID;
- /* Consider only regular and toast tables. */
- if (classForm->relkind != RELKIND_RELATION &&
- classForm->relkind != RELKIND_TOASTVALUE)
- continue;
-
relid = HeapTupleGetOid(tuple);
/* Fetch the pg_autovacuum tuple for the relation, if any */
- avTup = get_pg_autovacuum_tuple_relid(avRel, relid);
+ avTup = get_pg_autovacuum_tuple_relid(avRel, relid, NULL);
if (HeapTupleIsValid(avTup))
avForm = (Form_pg_autovacuum) GETSTRUCT(avTup);
* vacuum for wraparound, forcibly drop it. Otherwise just
* log a complaint.
*/
- if (wraparound && classForm->relkind == RELKIND_RELATION)
+ if (wraparound)
{
ObjectAddress object;
}
}
}
- else if (classForm->relkind == RELKIND_RELATION)
+ else
{
/* Plain relations that need work are added to table_oids */
if (dovacuum || doanalyze)
table_oids = lappend_oid(table_oids, relid);
- else if (OidIsValid(classForm->reltoastrelid))
+
+ /*
+ * Remember the association for the second pass. Note: we must do
+ * this even if the table is going to be vacuumed, because we
+ * don't automatically vacuum toast tables along the parent table.
+ */
+ if (OidIsValid(classForm->reltoastrelid))
{
- /*
- * If it doesn't appear to need vacuuming, but it has a toast
- * table, remember the association to revisit below.
- */
- av_relation *rel = palloc(sizeof(av_relation));
+ av_relation *hentry;
+ bool found;
- rel->ar_relid = relid;
- rel->ar_toastrelid = classForm->reltoastrelid;
+ hentry = hash_search(table_toast_map,
+ &classForm->reltoastrelid,
+ HASH_ENTER, &found);
- table_toast_list = lappend(table_toast_list, rel);
+ if (!found)
+ {
+ /* hash_search already filled in the key */
+ hentry->ar_relid = relid;
+ }
}
}
- else
- {
- /* TOAST relations that need vacuum are added to toast_oids */
- if (dovacuum)
- toast_oids = lappend_oid(toast_oids, relid);
- }
if (HeapTupleIsValid(avTup))
heap_freetuple(avTup);
}
heap_endscan(relScan);
- heap_close(avRel, AccessShareLock);
- heap_close(classRel, AccessShareLock);
- /*
- * Add to the list of tables to vacuum, the OIDs of the tables that
- * correspond to the saved OIDs of toast tables needing vacuum.
- */
- foreach(cell, toast_oids)
+ /* second pass: check TOAST tables */
+ ScanKeyInit(&key,
+ Anum_pg_class_relkind,
+ BTEqualStrategyNumber, F_CHAREQ,
+ CharGetDatum(RELKIND_TOASTVALUE));
+
+ relScan = heap_beginscan(classRel, SnapshotNow, 1, &key);
+ while ((tuple = heap_getnext(relScan, ForwardScanDirection)) != NULL)
{
- Oid toastoid = lfirst_oid(cell);
- ListCell *cell2;
+ Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple);
+ Form_pg_autovacuum avForm = NULL;
+ PgStat_StatTabEntry *tabentry;
+ HeapTuple avTup;
+ Oid relid;
+ bool dovacuum;
+ bool doanalyze;
+ bool wraparound;
- foreach(cell2, table_toast_list)
- {
- av_relation *ar = lfirst(cell2);
+ /*
+ * Skip temp tables (i.e. those in temp namespaces). We cannot safely
+ * process other backends' temp tables.
+ */
+ if (isAnyTempNamespace(classForm->relnamespace))
+ continue;
- if (ar->ar_toastrelid == toastoid)
- {
- table_oids = lappend_oid(table_oids, ar->ar_relid);
- break;
- }
- }
+ relid = HeapTupleGetOid(tuple);
+
+ /* Fetch the pg_autovacuum tuple for this rel */
+ avTup = get_pg_autovacuum_tuple_relid(avRel, relid, table_toast_map);
+
+ if (HeapTupleIsValid(avTup))
+ avForm = (Form_pg_autovacuum) GETSTRUCT(avTup);
+
+ /* Fetch the pgstat entry for this table */
+ tabentry = get_pgstat_tabentry_relid(relid, classForm->relisshared,
+ shared, dbentry);
+
+ relation_needs_vacanalyze(relid, avForm, classForm, tabentry,
+ &dovacuum, &doanalyze, &wraparound);
+
+ /* ignore analyze for toast tables */
+ if (dovacuum)
+ table_oids = lappend_oid(table_oids, relid);
}
- list_free_deep(table_toast_list);
- table_toast_list = NIL;
- list_free(toast_oids);
- toast_oids = NIL;
+ heap_endscan(relScan);
+ heap_close(avRel, AccessShareLock);
+ heap_close(classRel, AccessShareLock);
/*
* Create a buffer access strategy object for VACUUM to use. We want to
* vacuumed in the last 500ms (PGSTAT_STAT_INTERVAL). This is a bug.
*/
MemoryContextSwitchTo(AutovacMemCxt);
- tab = table_recheck_autovac(relid);
+ tab = table_recheck_autovac(relid, table_toast_map);
if (tab == NULL)
{
/* someone else vacuumed the table */
LWLockRelease(AutovacuumLock);
}
+ /*
+ * We leak table_toast_map here (among other things), but since we're going
+ * away soon, it's not a problem.
+ */
+
/*
* Update pg_database.datfrozenxid, and truncate pg_clog if possible. We
* only need to do this once, not after each table.
/*
* Returns a copy of the pg_autovacuum tuple for the given relid, or NULL if
* there isn't any. avRel is pg_autovacuum, already open and suitably locked.
+ *
+ * If table_toast_map is not null, use it to find an alternative OID with which
+ * to search a pg_autovacuum entry, if the passed relid does not yield one
+ * directly.
*/
static HeapTuple
-get_pg_autovacuum_tuple_relid(Relation avRel, Oid relid)
+get_pg_autovacuum_tuple_relid(Relation avRel, Oid relid,
+ HTAB *table_toast_map)
{
ScanKeyData entry[1];
SysScanDesc avScan;
systable_endscan(avScan);
+ if (!HeapTupleIsValid(avTup) && table_toast_map != NULL)
+ {
+ av_relation *hentry;
+ bool found;
+
+ hentry = hash_search(table_toast_map, &relid, HASH_FIND, &found);
+ if (found)
+ /* avoid second recursion */
+ avTup = get_pg_autovacuum_tuple_relid(avRel, hentry->ar_relid,
+ NULL);
+ }
+
return avTup;
}
/*
* table_recheck_autovac
*
- * Recheck whether a plain table still needs vacuum or analyze; be it because
- * it does directly, or because its TOAST table does. Return value is a valid
- * autovac_table pointer if it does, NULL otherwise.
+ * Recheck whether a table still needs vacuum or analyze. Return value is a
+ * valid autovac_table pointer if it does, NULL otherwise.
*
* Note that the returned autovac_table does not have the name fields set.
*/
static autovac_table *
-table_recheck_autovac(Oid relid)
+table_recheck_autovac(Oid relid, HTAB *table_toast_map)
{
Form_pg_autovacuum avForm = NULL;
Form_pg_class classForm;
bool doanalyze;
autovac_table *tab = NULL;
PgStat_StatTabEntry *tabentry;
- bool doit = false;
PgStat_StatDBEntry *shared;
PgStat_StatDBEntry *dbentry;
- bool wraparound,
- toast_wraparound = false;
+ bool wraparound;
/* use fresh stats */
autovac_refresh_stats();
return NULL;
classForm = (Form_pg_class) GETSTRUCT(classTup);
- /* fetch the pg_autovacuum entry, if any */
+ /*
+ * Fetch the pg_autovacuum entry, if any. For a toast table, also try the
+ * main rel's pg_autovacuum entry if there isn't one for the TOAST table
+ * itself.
+ */
avRel = heap_open(AutovacuumRelationId, AccessShareLock);
- avTup = get_pg_autovacuum_tuple_relid(avRel, relid);
+ avTup = get_pg_autovacuum_tuple_relid(avRel, relid,
+ classForm->relkind == RELKIND_TOASTVALUE ? table_toast_map : NULL);
+
if (HeapTupleIsValid(avTup))
avForm = (Form_pg_autovacuum) GETSTRUCT(avTup);
relation_needs_vacanalyze(relid, avForm, classForm, tabentry,
&dovacuum, &doanalyze, &wraparound);
- /* OK, it needs vacuum by itself */
- if (dovacuum)
- doit = true;
- /* it doesn't need vacuum, but what about it's TOAST table? */
- else if (OidIsValid(classForm->reltoastrelid))
- {
- Oid toastrelid = classForm->reltoastrelid;
- HeapTuple toastClassTup;
-
- toastClassTup = SearchSysCacheCopy(RELOID,
- ObjectIdGetDatum(toastrelid),
- 0, 0, 0);
- if (HeapTupleIsValid(toastClassTup))
- {
- bool toast_dovacuum;
- bool toast_doanalyze;
- bool toast_wraparound;
- Form_pg_class toastClassForm;
- PgStat_StatTabEntry *toasttabentry;
-
- toastClassForm = (Form_pg_class) GETSTRUCT(toastClassTup);
- toasttabentry = get_pgstat_tabentry_relid(toastrelid,
- toastClassForm->relisshared,
- shared, dbentry);
-
- /* note we use the pg_autovacuum entry for the main table */
- relation_needs_vacanalyze(toastrelid, avForm,
- toastClassForm, toasttabentry,
- &toast_dovacuum, &toast_doanalyze,
- &toast_wraparound);
- /* we only consider VACUUM for toast tables */
- if (toast_dovacuum)
- {
- dovacuum = true;
- doit = true;
- }
-
- heap_freetuple(toastClassTup);
- }
- }
-
- if (doanalyze)
- doit = true;
+ /* ignore ANALYZE for toast tables */
+ if (classForm->relkind == RELKIND_TOASTVALUE)
+ doanalyze = false;
- if (doit)
+ /* OK, it needs something done */
+ if (doanalyze || dovacuum)
{
int freeze_min_age;
int vac_cost_limit;
tab->at_freeze_min_age = freeze_min_age;
tab->at_vacuum_cost_limit = vac_cost_limit;
tab->at_vacuum_cost_delay = vac_cost_delay;
- tab->at_wraparound = wraparound || toast_wraparound;
+ tab->at_wraparound = wraparound;
tab->at_relname = NULL;
tab->at_nspname = NULL;
tab->at_datname = NULL;
/* Let pgstat know what we're doing */
autovac_report_activity(tab);
- vacuum(&vacstmt, tab->at_relid, bstrategy, tab->at_wraparound, true);
+ vacuum(&vacstmt, tab->at_relid, false, bstrategy, tab->at_wraparound, true);
}
/*
projects / postgresql / commitdiff