>From 97665ef1ca7d1847e90d4dfab38562135f01fb2b Mon Sep 17 00:00:00 2001 From: Alex Shulgin Date: Tue, 9 Dec 2014 16:35:14 +0300 Subject: [PATCH] WIP: track TRUNCATEs in pgstat transaction stats. The n_live_tup and n_dead_tup counters need to be set to 0 after a TRUNCATE on the relation. We can't issue a special message to the stats collector because the xact might be later aborted, so we track the fact that the relation was truncated during the xact (and reset this xact's insert/update/delete counters). When xact is committed, we use the `truncated' flag to reset the n_live_tup and n_dead_tup counters. --- src/backend/commands/tablecmds.c | 2 ++ src/backend/postmaster/pgstat.c | 70 ++++++++++++++++++++++++++++++++++++---- src/include/pgstat.h | 3 ++ 3 files changed, 68 insertions(+), 7 deletions(-) diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c new file mode 100644 index 1e737a0..192d033 *** a/src/backend/commands/tablecmds.c --- b/src/backend/commands/tablecmds.c *************** ExecuteTruncate(TruncateStmt *stmt) *** 1224,1229 **** --- 1224,1231 ---- */ reindex_relation(heap_relid, REINDEX_REL_PROCESS_TOAST); } + + pgstat_count_heap_truncate(rel); } /* diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c new file mode 100644 index c7f41a5..7ff66b5 *** a/src/backend/postmaster/pgstat.c --- b/src/backend/postmaster/pgstat.c *************** typedef struct TwoPhasePgStatRecord *** 200,208 **** PgStat_Counter tuples_updated; /* tuples updated in xact */ PgStat_Counter tuples_deleted; /* tuples deleted in xact */ Oid t_id; /* table's OID */ ! bool t_shared; /* is it a shared catalog? */ } TwoPhasePgStatRecord; /* * Info about current "snapshot" of stats file */ --- 200,211 ---- PgStat_Counter tuples_updated; /* tuples updated in xact */ PgStat_Counter tuples_deleted; /* tuples deleted in xact */ Oid t_id; /* table's OID */ ! char t_flags; /* see TWOPHASE_PGSTAT_RECORD_*_FLAGs */ } TwoPhasePgStatRecord; + #define TWOPHASE_PGSTAT_RECORD_SHARED_FLAG 0x01 /* is it a shared catalog? */ + #define TWOPHASE_PGSTAT_RECORD_TRUNC_FLAG 0x02 /* was the relation truncated? */ + /* * Info about current "snapshot" of stats file */ *************** pgstat_count_heap_delete(Relation rel) *** 1864,1869 **** --- 1867,1896 ---- } /* + * pgstat_count_heap_truncate - update tuple counters due to truncate + */ + void + pgstat_count_heap_truncate(Relation rel) + { + PgStat_TableStatus *pgstat_info = rel->pgstat_info; + + if (pgstat_info != NULL) + { + /* We have to log the effect at the proper transactional level */ + int nest_level = GetCurrentTransactionNestLevel(); + + if (pgstat_info->trans == NULL || + pgstat_info->trans->nest_level != nest_level) + add_tabstat_xact_level(pgstat_info, nest_level); + + pgstat_info->trans->tuples_inserted = 0; + pgstat_info->trans->tuples_updated = 0; + pgstat_info->trans->tuples_deleted = 0; + pgstat_info->trans->truncated = true; + } + } + + /* * pgstat_update_heap_dead_tuples - update dead-tuples count * * The semantics of this are that we are reporting the nontransactional *************** AtEOXact_PgStat(bool isCommit) *** 1927,1932 **** --- 1954,1961 ---- tabstat->t_counts.t_tuples_deleted += trans->tuples_deleted; if (isCommit) { + tabstat->t_counts.t_truncated = trans->truncated; + /* insert adds a live tuple, delete removes one */ tabstat->t_counts.t_delta_live_tuples += trans->tuples_inserted - trans->tuples_deleted; *************** AtEOSubXact_PgStat(bool isCommit, int ne *** 1991,1999 **** { if (trans->upper && trans->upper->nest_level == nestDepth - 1) { ! trans->upper->tuples_inserted += trans->tuples_inserted; ! trans->upper->tuples_updated += trans->tuples_updated; ! trans->upper->tuples_deleted += trans->tuples_deleted; tabstat->trans = trans->upper; pfree(trans); } --- 2020,2039 ---- { if (trans->upper && trans->upper->nest_level == nestDepth - 1) { ! if (trans->truncated) ! { ! trans->upper->truncated = true; ! /* replace upper xact stats with ours */ ! trans->upper->tuples_inserted = trans->tuples_inserted; ! trans->upper->tuples_updated = trans->tuples_updated; ! trans->upper->tuples_deleted = trans->tuples_deleted; ! } ! else ! { ! trans->upper->tuples_inserted += trans->tuples_inserted; ! trans->upper->tuples_updated += trans->tuples_updated; ! trans->upper->tuples_deleted += trans->tuples_deleted; ! } tabstat->trans = trans->upper; pfree(trans); } *************** AtPrepare_PgStat(void) *** 2071,2077 **** record.tuples_updated = trans->tuples_updated; record.tuples_deleted = trans->tuples_deleted; record.t_id = tabstat->t_id; ! record.t_shared = tabstat->t_shared; RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0, &record, sizeof(TwoPhasePgStatRecord)); --- 2111,2120 ---- record.tuples_updated = trans->tuples_updated; record.tuples_deleted = trans->tuples_deleted; record.t_id = tabstat->t_id; ! if (tabstat->t_shared) ! record.t_flags |= TWOPHASE_PGSTAT_RECORD_SHARED_FLAG; ! if (trans->truncated) ! record.t_flags |= TWOPHASE_PGSTAT_RECORD_TRUNC_FLAG; RegisterTwoPhaseRecord(TWOPHASE_RM_PGSTAT_ID, 0, &record, sizeof(TwoPhasePgStatRecord)); *************** pgstat_twophase_postcommit(TransactionId *** 2131,2142 **** PgStat_TableStatus *pgstat_info; /* Find or create a tabstat entry for the rel */ ! pgstat_info = get_tabstat_entry(rec->t_id, rec->t_shared); /* Same math as in AtEOXact_PgStat, commit case */ pgstat_info->t_counts.t_tuples_inserted += rec->tuples_inserted; pgstat_info->t_counts.t_tuples_updated += rec->tuples_updated; pgstat_info->t_counts.t_tuples_deleted += rec->tuples_deleted; pgstat_info->t_counts.t_delta_live_tuples += rec->tuples_inserted - rec->tuples_deleted; pgstat_info->t_counts.t_delta_dead_tuples += --- 2174,2190 ---- PgStat_TableStatus *pgstat_info; /* Find or create a tabstat entry for the rel */ ! pgstat_info = ! get_tabstat_entry(rec->t_id, ! (rec->t_flags & TWOPHASE_PGSTAT_RECORD_SHARED_FLAG) != 0); /* Same math as in AtEOXact_PgStat, commit case */ pgstat_info->t_counts.t_tuples_inserted += rec->tuples_inserted; pgstat_info->t_counts.t_tuples_updated += rec->tuples_updated; pgstat_info->t_counts.t_tuples_deleted += rec->tuples_deleted; + pgstat_info->t_counts.t_truncated = + ((rec->t_flags & TWOPHASE_PGSTAT_RECORD_TRUNC_FLAG) != 0); + pgstat_info->t_counts.t_delta_live_tuples += rec->tuples_inserted - rec->tuples_deleted; pgstat_info->t_counts.t_delta_dead_tuples += *************** pgstat_twophase_postabort(TransactionId *** 2160,2166 **** PgStat_TableStatus *pgstat_info; /* Find or create a tabstat entry for the rel */ ! pgstat_info = get_tabstat_entry(rec->t_id, rec->t_shared); /* Same math as in AtEOXact_PgStat, abort case */ pgstat_info->t_counts.t_tuples_inserted += rec->tuples_inserted; --- 2208,2217 ---- PgStat_TableStatus *pgstat_info; /* Find or create a tabstat entry for the rel */ ! pgstat_info = ! get_tabstat_entry(rec->t_id, ! (rec->t_flags & TWOPHASE_PGSTAT_RECORD_SHARED_FLAG) != 0); ! /* Same math as in AtEOXact_PgStat, abort case */ pgstat_info->t_counts.t_tuples_inserted += rec->tuples_inserted; *************** pgstat_recv_tabstat(PgStat_MsgTabstat *m *** 4685,4690 **** --- 4736,4746 ---- tabentry->tuples_updated += tabmsg->t_counts.t_tuples_updated; tabentry->tuples_deleted += tabmsg->t_counts.t_tuples_deleted; tabentry->tuples_hot_updated += tabmsg->t_counts.t_tuples_hot_updated; + if (tabmsg->t_counts.t_truncated) + { + tabentry->n_live_tuples = 0; + tabentry->n_dead_tuples = 0; + } tabentry->n_live_tuples += tabmsg->t_counts.t_delta_live_tuples; tabentry->n_dead_tuples += tabmsg->t_counts.t_delta_dead_tuples; tabentry->changes_since_analyze += tabmsg->t_counts.t_changed_tuples; diff --git a/src/include/pgstat.h b/src/include/pgstat.h new file mode 100644 index 0892533..5107f48 *** a/src/include/pgstat.h --- b/src/include/pgstat.h *************** typedef struct PgStat_TableCounts *** 103,108 **** --- 103,109 ---- PgStat_Counter t_tuples_updated; PgStat_Counter t_tuples_deleted; PgStat_Counter t_tuples_hot_updated; + bool t_truncated; PgStat_Counter t_delta_live_tuples; PgStat_Counter t_delta_dead_tuples; *************** typedef struct PgStat_TableXactStatus *** 164,169 **** --- 165,171 ---- PgStat_Counter tuples_inserted; /* tuples inserted in (sub)xact */ PgStat_Counter tuples_updated; /* tuples updated in (sub)xact */ PgStat_Counter tuples_deleted; /* tuples deleted in (sub)xact */ + bool truncated; /* relation got truncated in this (sub)xact */ int nest_level; /* subtransaction nest level */ /* links to other structs for same relation: */ struct PgStat_TableXactStatus *upper; /* next higher subxact if any */ *************** extern void pgstat_initstats(Relation re *** 916,921 **** --- 918,924 ---- extern void pgstat_count_heap_insert(Relation rel, int n); extern void pgstat_count_heap_update(Relation rel, bool hot); extern void pgstat_count_heap_delete(Relation rel); + extern void pgstat_count_heap_truncate(Relation rel); extern void pgstat_update_heap_dead_tuples(Relation rel, int delta); extern void pgstat_init_function_usage(FunctionCallInfoData *fcinfo, -- 2.1.0