diff options
Diffstat (limited to 'src/backend/utils/activity/pgstat_relation.c')
| -rw-r--r-- | src/backend/utils/activity/pgstat_relation.c | 592 |
1 files changed, 302 insertions, 290 deletions
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c index 51a87b66739..bec190c5897 100644 --- a/src/backend/utils/activity/pgstat_relation.c +++ b/src/backend/utils/activity/pgstat_relation.c @@ -19,6 +19,7 @@ #include "access/twophase_rmgr.h" #include "access/xact.h" +#include "catalog/partition.h" #include "postmaster/autovacuum.h" #include "utils/memutils.h" #include "utils/pgstat_internal.h" @@ -26,38 +27,6 @@ #include "utils/timestamp.h" -/* - * Structures in which backends store per-table info that's waiting to be - * sent to the collector. - * - * NOTE: once allocated, TabStatusArray structures are never moved or deleted - * for the life of the backend. Also, we zero out the t_id fields of the - * contained PgStat_TableStatus structs whenever they are not actively in use. - * This allows relcache pgstat_info pointers to be treated as long-lived data, - * avoiding repeated searches in pgstat_init_relation() when a relation is - * repeatedly opened during a transaction. - */ -#define TABSTAT_QUANTUM 100 /* we alloc this many at a time */ - - -typedef struct TabStatusArray -{ - struct TabStatusArray *tsa_next; /* link to next array, if any */ - int tsa_used; /* # entries currently used */ - PgStat_TableStatus tsa_entries[TABSTAT_QUANTUM]; /* per-table data */ -} TabStatusArray; - -static TabStatusArray *pgStatTabList = NULL; - -/* - * pgStatTabHash entry: map from relation OID to PgStat_TableStatus pointer - */ -typedef struct TabStatHashEntry -{ - Oid t_id; - PgStat_TableStatus *tsa_entry; -} TabStatHashEntry; - /* Record that's written to 2PC state file when pgstat state is persisted */ typedef struct TwoPhasePgStatRecord { @@ -74,8 +43,7 @@ typedef struct TwoPhasePgStatRecord } TwoPhasePgStatRecord; -static PgStat_TableStatus *get_tabstat_entry(Oid rel_id, bool isshared); -static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now); +static PgStat_TableStatus *pgstat_prep_relation_pending(Oid rel_id, bool isshared); static void add_tabstat_xact_level(PgStat_TableStatus *pgstat_info, int nest_level); static void ensure_tabstat_xact_level(PgStat_TableStatus *pgstat_info); static void save_truncdrop_counters(PgStat_TableXactStatus *trans, bool is_drop); @@ -83,19 +51,6 @@ static void restore_truncdrop_counters(PgStat_TableXactStatus *trans); /* - * Indicates if backend has some relation stats that it hasn't yet - * sent to the collector. - */ -bool have_relation_stats; - - -/* - * Hash table for O(1) t_id -> tsa_entry lookup - */ -static HTAB *pgStatTabHash = NULL; - - -/* * Copy stats between relations. This is used for things like REINDEX * CONCURRENTLY. */ @@ -103,43 +58,39 @@ void pgstat_copy_relation_stats(Relation dst, Relation src) { PgStat_StatTabEntry *srcstats; + PgStatShared_Relation *dstshstats; + PgStat_EntryRef *dst_ref; - srcstats = pgstat_fetch_stat_tabentry(RelationGetRelid(src)); - + srcstats = pgstat_fetch_stat_tabentry_ext(src->rd_rel->relisshared, + RelationGetRelid(src)); if (!srcstats) return; - if (pgstat_should_count_relation(dst)) - { - /* - * XXX: temporarily this does not actually quite do what the name - * says, and just copy index related fields. A subsequent commit will - * do more. - */ - - dst->pgstat_info->t_counts.t_numscans = srcstats->numscans; - dst->pgstat_info->t_counts.t_tuples_returned = srcstats->tuples_returned; - dst->pgstat_info->t_counts.t_tuples_fetched = srcstats->tuples_fetched; - dst->pgstat_info->t_counts.t_blocks_fetched = srcstats->blocks_fetched; - dst->pgstat_info->t_counts.t_blocks_hit = srcstats->blocks_hit; - - /* the data will be sent by the next pgstat_report_stat() call */ - } + dst_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, + dst->rd_rel->relisshared ? InvalidOid : MyDatabaseId, + RelationGetRelid(dst), + false); + + dstshstats = (PgStatShared_Relation *) dst_ref->shared_stats; + dstshstats->stats = *srcstats; + + pgstat_unlock_entry(dst_ref); } /* - * Initialize a relcache entry to count access statistics. - * Called whenever a relation is opened. + * Initialize a relcache entry to count access statistics. Called whenever a + * relation is opened. * - * We assume that a relcache entry's pgstat_info field is zeroed by - * relcache.c when the relcache entry is made; thereafter it is long-lived - * data. We can avoid repeated searches of the TabStatus arrays when the - * same relation is touched repeatedly within a transaction. + * We assume that a relcache entry's pgstat_info field is zeroed by relcache.c + * when the relcache entry is made; thereafter it is long-lived data. + * + * This does not create a reference to a stats entry in shared memory, nor + * allocate memory for the pending stats. That happens in + * pgstat_assoc_relation(). */ void pgstat_init_relation(Relation rel) { - Oid rel_id = rel->rd_id; char relkind = rel->rd_rel->relkind; /* @@ -147,27 +98,68 @@ pgstat_init_relation(Relation rel) */ if (!RELKIND_HAS_STORAGE(relkind) && relkind != RELKIND_PARTITIONED_TABLE) { + rel->pgstat_enabled = false; rel->pgstat_info = NULL; return; } - if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_counts) + if (!pgstat_track_counts) { + if (rel->pgstat_info) + pgstat_unlink_relation(rel); + /* We're not counting at all */ + rel->pgstat_enabled = false; rel->pgstat_info = NULL; return; } - /* - * If we already set up this relation in the current transaction, nothing - * to do. - */ - if (rel->pgstat_info != NULL && - rel->pgstat_info->t_id == rel_id) - return; + rel->pgstat_enabled = true; +} + +/* + * Prepare for statistics for this relation to be collected. + * + * This ensures we have a reference to the stats entry before stats can be + * generated. That is important because a relation drop in another connection + * could otherwise lead to the stats entry being dropped, which then later + * would get recreated when flushing stats. + * + * This is separate from pgstat_init_relation() as it is not uncommon for + * relcache entries to be opened without ever getting stats reported. + */ +void +pgstat_assoc_relation(Relation rel) +{ + Assert(rel->pgstat_enabled); + Assert(rel->pgstat_info == NULL); /* Else find or make the PgStat_TableStatus entry, and update link */ - rel->pgstat_info = get_tabstat_entry(rel_id, rel->rd_rel->relisshared); + rel->pgstat_info = pgstat_prep_relation_pending(RelationGetRelid(rel), + rel->rd_rel->relisshared); + + /* don't allow link a stats to multiple relcache entries */ + Assert(rel->pgstat_info->relation == NULL); + + /* mark this relation as the owner */ + rel->pgstat_info->relation = rel; +} + +/* + * Break the mutual link between a relcache entry and pending stats entry. + * This must be called whenever one end of the link is removed. + */ +void +pgstat_unlink_relation(Relation rel) +{ + /* remove the link to stats info if any */ + if (rel->pgstat_info == NULL) + return; + + /* link sanity check */ + Assert(rel->pgstat_info->relation == rel); + rel->pgstat_info->relation = NULL; + rel->pgstat_info = NULL; } /* @@ -187,9 +179,26 @@ pgstat_create_relation(Relation rel) void pgstat_drop_relation(Relation rel) { + int nest_level = GetCurrentTransactionNestLevel(); + PgStat_TableStatus *pgstat_info = rel->pgstat_info; + pgstat_drop_transactional(PGSTAT_KIND_RELATION, rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId, RelationGetRelid(rel)); + + /* + * Transactionally set counters to 0. That ensures that accesses to + * pg_stat_xact_all_tables inside the transaction show 0. + */ + if (pgstat_info && + pgstat_info->trans != NULL && + pgstat_info->trans->nest_level == nest_level) + { + save_truncdrop_counters(pgstat_info->trans, true); + pgstat_info->trans->tuples_inserted = 0; + pgstat_info->trans->tuples_updated = 0; + pgstat_info->trans->tuples_deleted = 0; + } } /* @@ -199,19 +208,52 @@ void pgstat_report_vacuum(Oid tableoid, bool shared, PgStat_Counter livetuples, PgStat_Counter deadtuples) { - PgStat_MsgVacuum msg; + PgStat_EntryRef *entry_ref; + PgStatShared_Relation *shtabentry; + PgStat_StatTabEntry *tabentry; + Oid dboid = (shared ? InvalidOid : MyDatabaseId); + TimestampTz ts; - if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_counts) + if (!pgstat_track_counts) return; - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_VACUUM); - msg.m_databaseid = shared ? InvalidOid : MyDatabaseId; - msg.m_tableoid = tableoid; - msg.m_autovacuum = IsAutoVacuumWorkerProcess(); - msg.m_vacuumtime = GetCurrentTimestamp(); - msg.m_live_tuples = livetuples; - msg.m_dead_tuples = deadtuples; - pgstat_send(&msg, sizeof(msg)); + /* Store the data in the table's hash table entry. */ + ts = GetCurrentTimestamp(); + + /* block acquiring lock for the same reason as pgstat_report_autovac() */ + entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, + dboid, tableoid, false); + + shtabentry = (PgStatShared_Relation *) entry_ref->shared_stats; + tabentry = &shtabentry->stats; + + tabentry->n_live_tuples = livetuples; + tabentry->n_dead_tuples = deadtuples; + + /* + * It is quite possible that a non-aggressive VACUUM ended up skipping + * various pages, however, we'll zero the insert counter here regardless. + * It's currently used only to track when we need to perform an "insert" + * autovacuum, which are mainly intended to freeze newly inserted tuples. + * Zeroing this may just mean we'll not try to vacuum the table again + * until enough tuples have been inserted to trigger another insert + * autovacuum. An anti-wraparound autovacuum will catch any persistent + * stragglers. + */ + tabentry->inserts_since_vacuum = 0; + + if (IsAutoVacuumWorkerProcess()) + { + tabentry->autovac_vacuum_timestamp = ts; + tabentry->autovac_vacuum_count++; + } + else + { + tabentry->vacuum_timestamp = ts; + tabentry->vacuum_count++; + } + + pgstat_unlock_entry(entry_ref); } /* @@ -225,9 +267,12 @@ pgstat_report_analyze(Relation rel, PgStat_Counter livetuples, PgStat_Counter deadtuples, bool resetcounter) { - PgStat_MsgAnalyze msg; + PgStat_EntryRef *entry_ref; + PgStatShared_Relation *shtabentry; + PgStat_StatTabEntry *tabentry; + Oid dboid = (rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId); - if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_counts) + if (!pgstat_track_counts) return; /* @@ -259,15 +304,39 @@ pgstat_report_analyze(Relation rel, deadtuples = Max(deadtuples, 0); } - pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ANALYZE); - msg.m_databaseid = rel->rd_rel->relisshared ? InvalidOid : MyDatabaseId; - msg.m_tableoid = RelationGetRelid(rel); - msg.m_autovacuum = IsAutoVacuumWorkerProcess(); - msg.m_resetcounter = resetcounter; - msg.m_analyzetime = GetCurrentTimestamp(); - msg.m_live_tuples = livetuples; - msg.m_dead_tuples = deadtuples; - pgstat_send(&msg, sizeof(msg)); + /* block acquiring lock for the same reason as pgstat_report_autovac() */ + entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_RELATION, dboid, + RelationGetRelid(rel), + false); + /* can't get dropped while accessed */ + Assert(entry_ref != NULL && entry_ref->shared_stats != NULL); + + shtabentry = (PgStatShared_Relation *) entry_ref->shared_stats; + tabentry = &shtabentry->stats; + + tabentry->n_live_tuples = livetuples; + tabentry->n_dead_tuples = deadtuples; + + /* + * If commanded, reset changes_since_analyze to zero. This forgets any + * changes that were committed while the ANALYZE was in progress, but we + * have no good way to estimate how many of those there were. + */ + if (resetcounter) + tabentry->changes_since_analyze = 0; + + if (IsAutoVacuumWorkerProcess()) + { + tabentry->autovac_analyze_timestamp = GetCurrentTimestamp(); + tabentry->autovac_analyze_count++; + } + else + { + tabentry->analyze_timestamp = GetCurrentTimestamp(); + tabentry->analyze_count++; + } + + pgstat_unlock_entry(entry_ref); } /* @@ -357,29 +426,60 @@ pgstat_update_heap_dead_tuples(Relation rel, int delta) } /* + * Support function for the SQL-callable pgstat* functions. Returns + * the collected statistics for one table or NULL. NULL doesn't mean + * that the table doesn't exist, just that there are no statistics, so the + * caller is better off to report ZERO instead. + */ +PgStat_StatTabEntry * +pgstat_fetch_stat_tabentry(Oid relid) +{ + PgStat_StatTabEntry *tabentry; + + tabentry = pgstat_fetch_stat_tabentry_ext(false, relid); + if (tabentry != NULL) + return tabentry; + + /* + * If we didn't find it, maybe it's a shared table. + */ + tabentry = pgstat_fetch_stat_tabentry_ext(true, relid); + return tabentry; +} + +/* + * More efficient version of pgstat_fetch_stat_tabentry(), allowing to specify + * whether the to-be-accessed table is a shared relation or not. + */ +PgStat_StatTabEntry * +pgstat_fetch_stat_tabentry_ext(bool shared, Oid reloid) +{ + Oid dboid = (shared ? InvalidOid : MyDatabaseId); + + return (PgStat_StatTabEntry *) + pgstat_fetch_entry(PGSTAT_KIND_RELATION, dboid, reloid); +} + +/* * find any existing PgStat_TableStatus entry for rel * - * If no entry, return NULL, don't create a new one + * Find any existing PgStat_TableStatus entry for rel_id in the current + * database. If not found, try finding from shared tables. * - * Note: if we got an error in the most recent execution of pgstat_report_stat, - * it's possible that an entry exists but there's no hashtable entry for it. - * That's okay, we'll treat this case as "doesn't exist". + * If no entry found, return NULL, don't create a new one */ PgStat_TableStatus * find_tabstat_entry(Oid rel_id) { - TabStatHashEntry *hash_entry; + PgStat_EntryRef *entry_ref; - /* If hashtable doesn't exist, there are no entries at all */ - if (!pgStatTabHash) - return NULL; + entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION, MyDatabaseId, rel_id); + if (!entry_ref) + entry_ref = pgstat_fetch_pending_entry(PGSTAT_KIND_RELATION, InvalidOid, rel_id); - hash_entry = hash_search(pgStatTabHash, &rel_id, HASH_FIND, NULL); - if (!hash_entry) - return NULL; - - /* Note that this step could also return NULL, but that's correct */ - return hash_entry->tsa_entry; + if (entry_ref) + return entry_ref->pending; + return NULL; } /* @@ -536,7 +636,7 @@ AtPrepare_PgStat_Relations(PgStat_SubXactStatus *xact_state) for (trans = xact_state->first; trans != NULL; trans = trans->next) { - PgStat_TableStatus *tabstat; + PgStat_TableStatus *tabstat PG_USED_FOR_ASSERTS_ONLY; TwoPhasePgStatRecord record; Assert(trans->nest_level == 1); @@ -594,7 +694,7 @@ pgstat_twophase_postcommit(TransactionId xid, uint16 info, PgStat_TableStatus *pgstat_info; /* Find or create a tabstat entry for the rel */ - pgstat_info = get_tabstat_entry(rec->t_id, rec->t_shared); + pgstat_info = pgstat_prep_relation_pending(rec->t_id, rec->t_shared); /* Same math as in AtEOXact_PgStat, commit case */ pgstat_info->t_counts.t_tuples_inserted += rec->tuples_inserted; @@ -630,7 +730,7 @@ pgstat_twophase_postabort(TransactionId xid, uint16 info, PgStat_TableStatus *pgstat_info; /* Find or create a tabstat entry for the rel */ - pgstat_info = get_tabstat_entry(rec->t_id, rec->t_shared); + pgstat_info = pgstat_prep_relation_pending(rec->t_id, rec->t_shared); /* Same math as in AtEOXact_PgStat, abort case */ if (rec->t_truncdropped) @@ -647,204 +747,116 @@ pgstat_twophase_postabort(TransactionId xid, uint16 info, } /* - * Subroutine for pgstat_report_stat: Send relation statistics + * Flush out pending stats for the entry + * + * If nowait is true, this function returns false if lock could not + * immediately acquired, otherwise true is returned. + * + * Some of the stats are copied to the corresponding pending database stats + * entry when successfully flushing. */ -void -pgstat_send_tabstats(TimestampTz now, bool disconnect) +bool +pgstat_relation_flush_cb(PgStat_EntryRef *entry_ref, bool nowait) { - /* we assume this inits to all zeroes: */ static const PgStat_TableCounts all_zeroes; - PgStat_MsgTabstat regular_msg; - PgStat_MsgTabstat shared_msg; - TabStatusArray *tsa; - int i; + Oid dboid; + PgStat_TableStatus *lstats; /* pending stats entry */ + PgStatShared_Relation *shtabstats; + PgStat_StatTabEntry *tabentry; /* table entry of shared stats */ + PgStat_StatDBEntry *dbentry; /* pending database entry */ - /* - * Destroy pgStatTabHash before we start invalidating PgStat_TableEntry - * entries it points to. (Should we fail partway through the loop below, - * it's okay to have removed the hashtable already --- the only - * consequence is we'd get multiple entries for the same table in the - * pgStatTabList, and that's safe.) - */ - if (pgStatTabHash) - hash_destroy(pgStatTabHash); - pgStatTabHash = NULL; + dboid = entry_ref->shared_entry->key.dboid; + lstats = (PgStat_TableStatus *) entry_ref->pending; + shtabstats = (PgStatShared_Relation *) entry_ref->shared_stats; /* - * Scan through the TabStatusArray struct(s) to find tables that actually - * have counts, and build messages to send. We have to separate shared - * relations from regular ones because the databaseid field in the message - * header has to depend on that. + * Ignore entries that didn't accumulate any actual counts, such as + * indexes that were opened by the planner but not used. */ - regular_msg.m_databaseid = MyDatabaseId; - shared_msg.m_databaseid = InvalidOid; - regular_msg.m_nentries = 0; - shared_msg.m_nentries = 0; - - for (tsa = pgStatTabList; tsa != NULL; tsa = tsa->tsa_next) + if (memcmp(&lstats->t_counts, &all_zeroes, + sizeof(PgStat_TableCounts)) == 0) { - for (i = 0; i < tsa->tsa_used; i++) - { - PgStat_TableStatus *entry = &tsa->tsa_entries[i]; - PgStat_MsgTabstat *this_msg; - PgStat_TableEntry *this_ent; + return true; + } - /* Shouldn't have any pending transaction-dependent counts */ - Assert(entry->trans == NULL); + if (!pgstat_lock_entry(entry_ref, nowait)) + return false; - /* - * Ignore entries that didn't accumulate any actual counts, such - * as indexes that were opened by the planner but not used. - */ - if (memcmp(&entry->t_counts, &all_zeroes, - sizeof(PgStat_TableCounts)) == 0) - continue; + /* add the values to the shared entry. */ + tabentry = &shtabstats->stats; - /* - * OK, insert data into the appropriate message, and send if full. - */ - this_msg = entry->t_shared ? &shared_msg : ®ular_msg; - this_ent = &this_msg->m_entry[this_msg->m_nentries]; - this_ent->t_id = entry->t_id; - memcpy(&this_ent->t_counts, &entry->t_counts, - sizeof(PgStat_TableCounts)); - if (++this_msg->m_nentries >= PGSTAT_NUM_TABENTRIES) - { - pgstat_send_tabstat(this_msg, now); - this_msg->m_nentries = 0; - } - } - /* zero out PgStat_TableStatus structs after use */ - MemSet(tsa->tsa_entries, 0, - tsa->tsa_used * sizeof(PgStat_TableStatus)); - tsa->tsa_used = 0; - } + tabentry->numscans += lstats->t_counts.t_numscans; + tabentry->tuples_returned += lstats->t_counts.t_tuples_returned; + tabentry->tuples_fetched += lstats->t_counts.t_tuples_fetched; + tabentry->tuples_inserted += lstats->t_counts.t_tuples_inserted; + tabentry->tuples_updated += lstats->t_counts.t_tuples_updated; + tabentry->tuples_deleted += lstats->t_counts.t_tuples_deleted; + tabentry->tuples_hot_updated += lstats->t_counts.t_tuples_hot_updated; /* - * Send partial messages. Make sure that any pending xact commit/abort - * and connection stats get counted, even if there are no table stats to - * send. + * If table was truncated/dropped, first reset the live/dead counters. */ - if (regular_msg.m_nentries > 0 || - pgStatXactCommit > 0 || pgStatXactRollback > 0 || disconnect) - pgstat_send_tabstat(®ular_msg, now); - if (shared_msg.m_nentries > 0) - pgstat_send_tabstat(&shared_msg, now); + if (lstats->t_counts.t_truncdropped) + { + tabentry->n_live_tuples = 0; + tabentry->n_dead_tuples = 0; + tabentry->inserts_since_vacuum = 0; + } - have_relation_stats = false; + tabentry->n_live_tuples += lstats->t_counts.t_delta_live_tuples; + tabentry->n_dead_tuples += lstats->t_counts.t_delta_dead_tuples; + tabentry->changes_since_analyze += lstats->t_counts.t_changed_tuples; + tabentry->inserts_since_vacuum += lstats->t_counts.t_tuples_inserted; + tabentry->blocks_fetched += lstats->t_counts.t_blocks_fetched; + tabentry->blocks_hit += lstats->t_counts.t_blocks_hit; + + /* Clamp n_live_tuples in case of negative delta_live_tuples */ + tabentry->n_live_tuples = Max(tabentry->n_live_tuples, 0); + /* Likewise for n_dead_tuples */ + tabentry->n_dead_tuples = Max(tabentry->n_dead_tuples, 0); + + pgstat_unlock_entry(entry_ref); + + /* The entry was successfully flushed, add the same to database stats */ + dbentry = pgstat_prep_database_pending(dboid); + dbentry->n_tuples_returned += lstats->t_counts.t_tuples_returned; + dbentry->n_tuples_fetched += lstats->t_counts.t_tuples_fetched; + dbentry->n_tuples_inserted += lstats->t_counts.t_tuples_inserted; + dbentry->n_tuples_updated += lstats->t_counts.t_tuples_updated; + dbentry->n_tuples_deleted += lstats->t_counts.t_tuples_deleted; + dbentry->n_blocks_fetched += lstats->t_counts.t_blocks_fetched; + dbentry->n_blocks_hit += lstats->t_counts.t_blocks_hit; + + return true; } -/* - * Subroutine for pgstat_send_tabstats: finish and send one tabstat message - */ -static void -pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now) +void +pgstat_relation_delete_pending_cb(PgStat_EntryRef *entry_ref) { - int n; - int len; - - /* It's unlikely we'd get here with no socket, but maybe not impossible */ - if (pgStatSock == PGINVALID_SOCKET) - return; + PgStat_TableStatus *pending = (PgStat_TableStatus *) entry_ref->pending; - /* - * Report and reset accumulated xact commit/rollback and I/O timings - * whenever we send a normal tabstat message - */ - pgstat_update_dbstats(tsmsg, now); - - n = tsmsg->m_nentries; - len = offsetof(PgStat_MsgTabstat, m_entry[0]) + - n * sizeof(PgStat_TableEntry); - - pgstat_setheader(&tsmsg->m_hdr, PGSTAT_MTYPE_TABSTAT); - pgstat_send(tsmsg, len); + if (pending->relation) + pgstat_unlink_relation(pending->relation); } /* - * find or create a PgStat_TableStatus entry for rel + * Find or create a PgStat_TableStatus entry for rel. New entry is created and + * initialized if not exists. */ static PgStat_TableStatus * -get_tabstat_entry(Oid rel_id, bool isshared) +pgstat_prep_relation_pending(Oid rel_id, bool isshared) { - TabStatHashEntry *hash_entry; - PgStat_TableStatus *entry; - TabStatusArray *tsa; - bool found; - - pgstat_assert_is_up(); + PgStat_EntryRef *entry_ref; + PgStat_TableStatus *pending; - have_relation_stats = true; - - /* - * Create hash table if we don't have it already. - */ - if (pgStatTabHash == NULL) - { - HASHCTL ctl; - - ctl.keysize = sizeof(Oid); - ctl.entrysize = sizeof(TabStatHashEntry); - - pgStatTabHash = hash_create("pgstat TabStatusArray lookup hash table", - TABSTAT_QUANTUM, - &ctl, - HASH_ELEM | HASH_BLOBS); - } - - /* - * Find an entry or create a new one. - */ - hash_entry = hash_search(pgStatTabHash, &rel_id, HASH_ENTER, &found); - if (!found) - { - /* initialize new entry with null pointer */ - hash_entry->tsa_entry = NULL; - } - - /* - * If entry is already valid, we're done. - */ - if (hash_entry->tsa_entry) - return hash_entry->tsa_entry; - - /* - * Locate the first pgStatTabList entry with free space, making a new list - * entry if needed. Note that we could get an OOM failure here, but if so - * we have left the hashtable and the list in a consistent state. - */ - if (pgStatTabList == NULL) - { - /* Set up first pgStatTabList entry */ - pgStatTabList = (TabStatusArray *) - MemoryContextAllocZero(TopMemoryContext, - sizeof(TabStatusArray)); - } - - tsa = pgStatTabList; - while (tsa->tsa_used >= TABSTAT_QUANTUM) - { - if (tsa->tsa_next == NULL) - tsa->tsa_next = (TabStatusArray *) - MemoryContextAllocZero(TopMemoryContext, - sizeof(TabStatusArray)); - tsa = tsa->tsa_next; - } - - /* - * Allocate a PgStat_TableStatus entry within this list entry. We assume - * the entry was already zeroed, either at creation or after last use. - */ - entry = &tsa->tsa_entries[tsa->tsa_used++]; - entry->t_id = rel_id; - entry->t_shared = isshared; - - /* - * Now we can fill the entry in pgStatTabHash. - */ - hash_entry->tsa_entry = entry; + entry_ref = pgstat_prep_pending_entry(PGSTAT_KIND_RELATION, + isshared ? InvalidOid : MyDatabaseId, + rel_id, NULL); + pending = entry_ref->pending; + pending->t_id = rel_id; + pending->t_shared = isshared; - return entry; + return pending; } /* |