diff options
Diffstat (limited to 'src/backend/postmaster/autovacuum.c')
| -rw-r--r-- | src/backend/postmaster/autovacuum.c | 270 |
1 files changed, 136 insertions, 134 deletions
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c index 9aeecec7a6e..1081cf83e9c 100644 --- a/src/backend/postmaster/autovacuum.c +++ b/src/backend/postmaster/autovacuum.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.4 2005/08/15 16:25:17 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.5 2005/10/15 02:49:23 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -69,17 +69,17 @@ static time_t last_autovac_start_time = 0; static time_t last_autovac_stop_time = 0; /* Memory context for long-lived data */ -static MemoryContext AutovacMemCxt; +static MemoryContext AutovacMemCxt; /* struct to keep list of candidate databases for vacuum */ typedef struct autovac_dbase { - Oid oid; - char *name; - TransactionId frozenxid; - TransactionId vacuumxid; + Oid oid; + char *name; + TransactionId frozenxid; + TransactionId vacuumxid; PgStat_StatDBEntry *entry; - int32 age; + int32 age; } autovac_dbase; /* struct to keep track of tables to vacuum and/or analyze */ @@ -102,12 +102,12 @@ static void process_whole_db(void); static void do_autovacuum(PgStat_StatDBEntry *dbentry); static List *autovac_get_database_list(void); static void test_rel_for_autovac(Oid relid, PgStat_StatTabEntry *tabentry, - Form_pg_class classForm, - Form_pg_autovacuum avForm, - List **vacuum_tables, - List **toast_table_ids); + Form_pg_class classForm, + Form_pg_autovacuum avForm, + List **vacuum_tables, + List **toast_table_ids); static void autovacuum_do_vac_analyze(List *relids, bool dovacuum, - bool doanalyze, bool freeze); + bool doanalyze, bool freeze); /* @@ -126,16 +126,16 @@ autovac_start(void) return 0; /* - * Do nothing if too soon since last autovacuum exit. This limits - * how often the daemon runs. Since the time per iteration can be - * quite variable, it seems more useful to measure/control the time - * since last subprocess exit than since last subprocess launch. + * Do nothing if too soon since last autovacuum exit. This limits how + * often the daemon runs. Since the time per iteration can be quite + * variable, it seems more useful to measure/control the time since last + * subprocess exit than since last subprocess launch. * - * However, we *also* check the time since last subprocess launch; - * this prevents thrashing under fork-failure conditions. + * However, we *also* check the time since last subprocess launch; this + * prevents thrashing under fork-failure conditions. * - * Note that since we will be re-called from the postmaster main loop, - * we will get another chance later if we do nothing now. + * Note that since we will be re-called from the postmaster main loop, we + * will get another chance later if we do nothing now. * * XXX todo: implement sleep scale factor that existed in contrib code. */ @@ -151,14 +151,14 @@ autovac_start(void) last_autovac_start_time = curtime; #ifdef EXEC_BACKEND - switch((AutoVacPID = autovac_forkexec())) + switch ((AutoVacPID = autovac_forkexec())) #else - switch((AutoVacPID = fork_process())) + switch ((AutoVacPID = fork_process())) #endif { case -1: ereport(LOG, - (errmsg("could not fork autovacuum process: %m"))); + (errmsg("could not fork autovacuum process: %m"))); return 0; #ifndef EXEC_BACKEND @@ -201,14 +201,14 @@ autovac_forkexec(void) av[ac++] = "postgres"; av[ac++] = "-forkautovac"; - av[ac++] = NULL; /* filled in by postmaster_forkexec */ + av[ac++] = NULL; /* filled in by postmaster_forkexec */ av[ac] = NULL; Assert(ac < lengthof(av)); return postmaster_forkexec(ac, av); } -#endif /* EXEC_BACKEND */ +#endif /* EXEC_BACKEND */ /* * AutoVacMain @@ -216,12 +216,12 @@ autovac_forkexec(void) NON_EXEC_STATIC void AutoVacMain(int argc, char *argv[]) { - ListCell *cell; - List *dblist; - TransactionId nextXid; - autovac_dbase *db; - bool whole_db; - sigjmp_buf local_sigjmp_buf; + ListCell *cell; + List *dblist; + TransactionId nextXid; + autovac_dbase *db; + bool whole_db; + sigjmp_buf local_sigjmp_buf; /* we are a postmaster subprocess now */ IsUnderPostmaster = true; @@ -240,18 +240,18 @@ AutoVacMain(int argc, char *argv[]) SetProcessingMode(InitProcessing); /* - * Set up signal handlers. We operate on databases much like a - * regular backend, so we use the same signal handling. See - * equivalent code in tcop/postgres.c. + * Set up signal handlers. We operate on databases much like a regular + * backend, so we use the same signal handling. See equivalent code in + * tcop/postgres.c. * - * Currently, we don't pay attention to postgresql.conf changes - * that happen during a single daemon iteration, so we can ignore - * SIGHUP. + * Currently, we don't pay attention to postgresql.conf changes that happen + * during a single daemon iteration, so we can ignore SIGHUP. */ pqsignal(SIGHUP, SIG_IGN); + /* - * Presently, SIGINT will lead to autovacuum shutdown, because that's - * how we handle ereport(ERROR). It could be improved however. + * Presently, SIGINT will lead to autovacuum shutdown, because that's how + * we handle ereport(ERROR). It could be improved however. */ pqsignal(SIGINT, StatementCancelHandler); pqsignal(SIGTERM, die); @@ -282,9 +282,9 @@ AutoVacMain(int argc, char *argv[]) EmitErrorReport(); /* - * We can now go away. Note that because we'll call InitProcess, - * a callback will be registered to do ProcKill, which will clean - * up necessary state. + * We can now go away. Note that because we'll call InitProcess, a + * callback will be registered to do ProcKill, which will clean up + * necessary state. */ proc_exit(0); } @@ -298,9 +298,8 @@ AutoVacMain(int argc, char *argv[]) dblist = autovac_get_database_list(); /* - * Get the next Xid that was current as of the last checkpoint. - * We need it to determine whether databases are about to need - * database-wide vacuums. + * Get the next Xid that was current as of the last checkpoint. We need it + * to determine whether databases are about to need database-wide vacuums. */ nextXid = GetRecentNextXid(); @@ -309,37 +308,36 @@ AutoVacMain(int argc, char *argv[]) * recently auto-vacuumed, or one that needs database-wide vacuum (to * prevent Xid wraparound-related data loss). * - * Note that a database with no stats entry is not considered, except - * for Xid wraparound purposes. The theory is that if no one has ever - * connected to it since the stats were last initialized, it doesn't - * need vacuuming. + * Note that a database with no stats entry is not considered, except for Xid + * wraparound purposes. The theory is that if no one has ever connected + * to it since the stats were last initialized, it doesn't need vacuuming. * * XXX This could be improved if we had more info about whether it needs * vacuuming before connecting to it. Perhaps look through the pgstats * data for the database's tables? One idea is to keep track of the * number of new and dead tuples per database in pgstats. However it - * isn't clear how to construct a metric that measures that and not - * cause starvation for less busy databases. + * isn't clear how to construct a metric that measures that and not cause + * starvation for less busy databases. */ db = NULL; whole_db = false; foreach(cell, dblist) { - autovac_dbase *tmp = lfirst(cell); - bool this_whole_db; - int32 freeze_age, - vacuum_age; + autovac_dbase *tmp = lfirst(cell); + bool this_whole_db; + int32 freeze_age, + vacuum_age; /* * We look for the database that most urgently needs a database-wide - * vacuum. We decide that a database-wide vacuum is needed 100000 + * vacuum. We decide that a database-wide vacuum is needed 100000 * transactions sooner than vacuum.c's vac_truncate_clog() would * decide to start giving warnings. If any such db is found, we * ignore all other dbs. * - * Unlike vacuum.c, we also look at vacuumxid. This is so that - * pg_clog can be kept trimmed to a reasonable size. + * Unlike vacuum.c, we also look at vacuumxid. This is so that pg_clog + * can be kept trimmed to a reasonable size. */ freeze_age = (int32) (nextXid - tmp->frozenxid); vacuum_age = (int32) (nextXid - tmp->vacuumxid); @@ -373,8 +371,8 @@ AutoVacMain(int argc, char *argv[]) * modified, after the database was dropped from the pg_database * table. (This is of course a not-very-bulletproof test, but it's * cheap to make. If we do mistakenly choose a recently dropped - * database, InitPostgres will fail and we'll drop out until the - * next autovac run.) + * database, InitPostgres will fail and we'll drop out until the next + * autovac run.) */ if (tmp->entry->destroy != 0) continue; @@ -390,12 +388,12 @@ AutoVacMain(int argc, char *argv[]) if (db) { /* - * Report autovac startup to the stats collector. We deliberately - * do this before InitPostgres, so that the last_autovac_time will - * get updated even if the connection attempt fails. This is to - * prevent autovac from getting "stuck" repeatedly selecting an - * unopenable database, rather than making any progress on stuff - * it can connect to. + * Report autovac startup to the stats collector. We deliberately do + * this before InitPostgres, so that the last_autovac_time will get + * updated even if the connection attempt fails. This is to prevent + * autovac from getting "stuck" repeatedly selecting an unopenable + * database, rather than making any progress on stuff it can connect + * to. */ pgstat_report_autovac(db->oid); @@ -431,18 +429,18 @@ AutoVacMain(int argc, char *argv[]) /* * autovac_get_database_list * - * Return a list of all databases. Note we cannot use pg_database, + * Return a list of all databases. Note we cannot use pg_database, * because we aren't connected yet; we use the flat database file. */ static List * autovac_get_database_list(void) { - char *filename; - List *dblist = NIL; - char thisname[NAMEDATALEN]; - FILE *db_file; - Oid db_id; - Oid db_tablespace; + char *filename; + List *dblist = NIL; + char thisname[NAMEDATALEN]; + FILE *db_file; + Oid db_id; + Oid db_tablespace; TransactionId db_frozenxid; TransactionId db_vacuumxid; @@ -457,7 +455,7 @@ autovac_get_database_list(void) &db_tablespace, &db_frozenxid, &db_vacuumxid)) { - autovac_dbase *db; + autovac_dbase *db; db = (autovac_dbase *) palloc(sizeof(autovac_dbase)); @@ -486,12 +484,12 @@ autovac_get_database_list(void) static void process_whole_db(void) { - Relation dbRel; - ScanKeyData entry[1]; - SysScanDesc scan; - HeapTuple tup; + Relation dbRel; + ScanKeyData entry[1]; + SysScanDesc scan; + HeapTuple tup; Form_pg_database dbForm; - bool freeze; + bool freeze; /* Start a transaction so our commands have one to play into. */ StartTransactionCommand(); @@ -545,23 +543,22 @@ process_whole_db(void) static void do_autovacuum(PgStat_StatDBEntry *dbentry) { - Relation classRel, - avRel; - HeapTuple tuple; - HeapScanDesc relScan; - List *vacuum_tables = NIL; - List *toast_table_ids = NIL; - ListCell *cell; + Relation classRel, + avRel; + HeapTuple tuple; + HeapScanDesc relScan; + List *vacuum_tables = NIL; + List *toast_table_ids = NIL; + ListCell *cell; PgStat_StatDBEntry *shared; /* Start a transaction so our commands have one to play into. */ StartTransactionCommand(); /* - * StartTransactionCommand and CommitTransactionCommand will - * automatically switch to other contexts. We need this one - * to keep the list of relations to vacuum/analyze across - * transactions. + * StartTransactionCommand and CommitTransactionCommand will automatically + * switch to other contexts. We need this one to keep the list of + * relations to vacuum/analyze across transactions. */ MemoryContextSwitchTo(AutovacMemCxt); @@ -574,19 +571,19 @@ do_autovacuum(PgStat_StatDBEntry *dbentry) /* * Scan pg_class and 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. + * 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. * * 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 + * 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. + * vacuuming; we go back and re-mark them after finding all the vacuumable + * toast tables. */ relScan = heap_beginscan(classRel, SnapshotNow, 0, NULL); @@ -595,9 +592,9 @@ do_autovacuum(PgStat_StatDBEntry *dbentry) Form_pg_class classForm = (Form_pg_class) GETSTRUCT(tuple); Form_pg_autovacuum avForm = NULL; PgStat_StatTabEntry *tabentry; - SysScanDesc avScan; + SysScanDesc avScan; HeapTuple avTup; - ScanKeyData entry[1]; + ScanKeyData entry[1]; Oid relid; /* Consider only regular and toast tables. */ @@ -606,8 +603,8 @@ do_autovacuum(PgStat_StatDBEntry *dbentry) continue; /* - * Skip temp tables (i.e. those in temp namespaces). We cannot - * safely process other backends' temp tables. + * Skip temp tables (i.e. those in temp namespaces). We cannot safely + * process other backends' temp tables. */ if (isTempNamespace(classForm->relnamespace)) continue; @@ -687,7 +684,7 @@ do_autovacuum(PgStat_StatDBEntry *dbentry) /* * test_rel_for_autovac * - * Check whether a table needs to be vacuumed or analyzed. Add it to the + * Check whether a table needs to be vacuumed or analyzed. Add it to the * appropriate output list if so. * * A table needs to be vacuumed if the number of dead tuples exceeds a @@ -718,33 +715,37 @@ test_rel_for_autovac(Oid relid, PgStat_StatTabEntry *tabentry, List **vacuum_tables, List **toast_table_ids) { - Relation rel; - float4 reltuples; /* pg_class.reltuples */ + Relation rel; + float4 reltuples; /* pg_class.reltuples */ + /* constants from pg_autovacuum or GUC variables */ - int vac_base_thresh, - anl_base_thresh; - float4 vac_scale_factor, - anl_scale_factor; + int vac_base_thresh, + anl_base_thresh; + float4 vac_scale_factor, + anl_scale_factor; + /* thresholds calculated from above constants */ - float4 vacthresh, - anlthresh; + float4 vacthresh, + anlthresh; + /* number of vacuum (resp. analyze) tuples at this time */ - float4 vactuples, - anltuples; + float4 vactuples, + anltuples; + /* cost-based vacuum delay parameters */ - int vac_cost_limit; - int vac_cost_delay; - bool dovacuum; - bool doanalyze; + int vac_cost_limit; + int vac_cost_delay; + bool dovacuum; + bool doanalyze; /* User disabled it in pg_autovacuum? */ if (avForm && !avForm->enabled) return; /* - * Skip a table not found in stat hash. If it's not acted upon, - * there's no need to vacuum it. (Note that database-level check - * will take care of Xid wraparound.) + * Skip a table not found in stat hash. If it's not acted upon, there's + * no need to vacuum it. (Note that database-level check will take care + * of Xid wraparound.) */ if (!PointerIsValid(tabentry)) return; @@ -805,9 +806,9 @@ test_rel_for_autovac(Oid relid, PgStat_StatTabEntry *tabentry, anlthresh = (float4) anl_base_thresh + anl_scale_factor * reltuples; /* - * Note that we don't need to take special consideration for stat - * reset, because if that happens, the last vacuum and analyze counts - * will be reset too. + * Note that we don't need to take special consideration for stat reset, + * because if that happens, the last vacuum and analyze counts will be + * reset too. */ elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), anl: %.0f (threshold %.0f)", @@ -863,27 +864,27 @@ test_rel_for_autovac(Oid relid, PgStat_StatTabEntry *tabentry, /* * autovacuum_do_vac_analyze - * Vacuum and/or analyze a list of tables; or all tables if relids = NIL + * Vacuum and/or analyze a list of tables; or all tables if relids = NIL */ static void autovacuum_do_vac_analyze(List *relids, bool dovacuum, bool doanalyze, bool freeze) { - VacuumStmt *vacstmt; - MemoryContext old_cxt; - + VacuumStmt *vacstmt; + MemoryContext old_cxt; + /* * The node must survive transaction boundaries, so make sure we create it * in a long-lived context */ old_cxt = MemoryContextSwitchTo(AutovacMemCxt); - + vacstmt = makeNode(VacuumStmt); /* * Point QueryContext to the autovac memory context to fake out the - * PreventTransactionChain check inside vacuum(). Note that this - * is also why we palloc vacstmt instead of just using a local variable. + * PreventTransactionChain check inside vacuum(). Note that this is also + * why we palloc vacstmt instead of just using a local variable. */ QueryContext = CurrentMemoryContext; @@ -904,8 +905,8 @@ autovacuum_do_vac_analyze(List *relids, bool dovacuum, bool doanalyze, /* * AutoVacuumingActive - * Check GUC vars and report whether the autovacuum process should be - * running. + * Check GUC vars and report whether the autovacuum process should be + * running. */ bool AutoVacuumingActive(void) @@ -918,7 +919,7 @@ AutoVacuumingActive(void) /* * autovac_init - * This is called at postmaster initialization. + * This is called at postmaster initialization. * * Annoy the user if he got it wrong. */ @@ -933,6 +934,7 @@ autovac_init(void) ereport(WARNING, (errmsg("autovacuum not started because of misconfiguration"), errhint("Enable options \"stats_start_collector\" and \"stats_row_level\"."))); + /* * Set the GUC var so we don't fork autovacuum uselessly, and also to * help debugging. @@ -943,7 +945,7 @@ autovac_init(void) /* * IsAutoVacuumProcess - * Return whether this process is an autovacuum process. + * Return whether this process is an autovacuum process. */ bool IsAutoVacuumProcess(void) |