From 7c5b9441b53af95df63f8e82e3f52ad1784a2b09 Mon Sep 17 00:00:00 2001 From: Bertrand Drouvot Date: Fri, 8 Aug 2025 02:54:32 +0000 Subject: [PATCH v1 04/10] Adding idx_tup_fetch to pg_stat_backend Adding per backend number of live rows fetched by index scans. XXX: Bump catversion. --- doc/src/sgml/monitoring.sgml | 9 +++++++++ src/backend/access/heap/heapam_handler.c | 1 + src/backend/access/index/indexam.c | 3 +++ src/backend/catalog/system_views.sql | 1 + src/backend/utils/activity/pgstat_backend.c | 4 ++++ src/backend/utils/adt/pgstatfuncs.c | 3 ++- src/include/catalog/pg_proc.dat | 6 +++--- src/include/pgstat.h | 3 +++ src/test/regress/expected/rules.out | 3 ++- src/test/regress/expected/stats.out | 15 +++++++++------ src/test/regress/sql/stats.sql | 9 ++++++--- 11 files changed, 43 insertions(+), 14 deletions(-) 14.1% doc/src/sgml/ 4.8% src/backend/access/ 6.2% src/backend/utils/activity/ 7.5% src/backend/utils/adt/ 17.2% src/include/catalog/ 6.3% src/include/ 27.7% src/test/regress/expected/ 14.4% src/test/regress/sql/ diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index 3fdc3d639e6..2bfd016a2ff 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1240,6 +1240,15 @@ description | Waiting for a newly initialized WAL file to reach durable storage + + + idx_tup_fetch bigint + + + The number of live rows fetched by index scans. + + + stats_reset timestamp with time zone diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c index 050ed0a79a3..ff86b3e67d4 100644 --- a/src/backend/access/heap/heapam_handler.c +++ b/src/backend/access/heap/heapam_handler.c @@ -2156,6 +2156,7 @@ heapam_scan_bitmap_next_tuple(TableScanDesc scan, ItemPointerSet(&hscan->rs_ctup.t_self, hscan->rs_cblock, targoffset); pgstat_count_heap_fetch(scan->rs_rd); + pgstat_count_backend_rel_idx_tup_fetch(); /* * Set up the result slot to point to this tuple. Note that the slot diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c index 219df1971da..d7d06266e70 100644 --- a/src/backend/access/index/indexam.c +++ b/src/backend/access/index/indexam.c @@ -686,7 +686,10 @@ index_fetch_heap(IndexScanDesc scan, TupleTableSlot *slot) &scan->xs_heap_continue, &all_dead); if (found) + { pgstat_count_heap_fetch(scan->indexRelation); + pgstat_count_backend_rel_idx_tup_fetch(); + } /* * If we scanned a whole HOT chain and found only dead tuples, tell index diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql index ea2f4785602..dd85b78a6dc 100644 --- a/src/backend/catalog/system_views.sql +++ b/src/backend/catalog/system_views.sql @@ -916,6 +916,7 @@ CREATE VIEW pg_stat_backend AS S.pid, S.seq_scan, S.seq_tup_read, + S.idx_tup_fetch, S.stats_reset FROM pg_stat_get_backend_statistics(NULL) AS S; diff --git a/src/backend/utils/activity/pgstat_backend.c b/src/backend/utils/activity/pgstat_backend.c index 85da2d23fc7..282f62dd0d3 100644 --- a/src/backend/utils/activity/pgstat_backend.c +++ b/src/backend/utils/activity/pgstat_backend.c @@ -288,6 +288,7 @@ pgstat_flush_backend_entry_rel(PgStat_EntryRef *entry_ref) BACKENDREL_ACC(heap_scan); BACKENDREL_ACC(seq_tup_read); + BACKENDREL_ACC(idx_tup_fetch); #undef BACKENDREL_ACC /* @@ -463,3 +464,6 @@ PGSTAT_COUNT_BACKEND_FUNC(heap_scan) /* pgstat_count_backend_rel_seq_tup_read */ PGSTAT_COUNT_BACKEND_FUNC(seq_tup_read) + +/* pgstat_count_backend_rel_idx_tup_fetch */ +PGSTAT_COUNT_BACKEND_FUNC(idx_tup_fetch) diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index c8f2b2a73d4..d050bcf8ed8 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -691,7 +691,7 @@ pg_stat_get_activity(PG_FUNCTION_ARGS) Datum pg_stat_get_backend_statistics(PG_FUNCTION_ARGS) { -#define PG_STAT_GET_BACKEND_STATS_COLS 4 +#define PG_STAT_GET_BACKEND_STATS_COLS 5 int num_backends = pgstat_fetch_stat_numbackends(); int curr_backend; int pid = PG_ARGISNULL(0) ? -1 : PG_GETARG_INT32(0); @@ -727,6 +727,7 @@ pg_stat_get_backend_statistics(PG_FUNCTION_ARGS) values[i++] = Int64GetDatum(backend_stats->heap_scan); values[i++] = Int64GetDatum(backend_stats->seq_tup_read); + values[i++] = Int64GetDatum(backend_stats->idx_tup_fetch); if (backend_stats->stat_reset_timestamp != 0) values[i] = TimestampTzGetDatum(backend_stats->stat_reset_timestamp); diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 797a3f22db5..a9709214d88 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -5646,9 +5646,9 @@ proname => 'pg_stat_get_backend_statistics', prorows => '100', proisstrict => 'f', proretset => 't', provolatile => 's', proparallel => 'r', prorettype => 'record', proargtypes => 'int4', - proallargtypes => '{int4,int4,int8,int8,timestamptz}', - proargmodes => '{i,o,o,o,o}', - proargnames => '{pid,pid,seq_scan,seq_tup_read,stats_reset}', + proallargtypes => '{int4,int4,int8,int8,int8,timestamptz}', + proargmodes => '{i,o,o,o,o,o}', + proargnames => '{pid,pid,seq_scan,seq_tup_read,idx_tup_fetch,stats_reset}', prosrc => 'pg_stat_get_backend_statistics' }, { oid => '6318', descr => 'describe wait events', proname => 'pg_get_wait_events', procost => '10', prorows => '250', diff --git a/src/include/pgstat.h b/src/include/pgstat.h index d634fe8e746..64739d04e5a 100644 --- a/src/include/pgstat.h +++ b/src/include/pgstat.h @@ -492,12 +492,14 @@ typedef struct PgStat_Backend PgStat_WalCounters wal_counters; PgStat_Counter heap_scan; PgStat_Counter seq_tup_read; + PgStat_Counter idx_tup_fetch; } PgStat_Backend; typedef struct PgStat_BackendRelPending { PgStat_Counter heap_scan; PgStat_Counter seq_tup_read; + PgStat_Counter idx_tup_fetch; } PgStat_BackendRelPending; /* --------- @@ -579,6 +581,7 @@ extern void pgstat_create_backend(ProcNumber procnum); /* used to track backend relations related stats */ extern void pgstat_count_backend_rel_heap_scan(void); extern void pgstat_count_backend_rel_seq_tup_read(void); +extern void pgstat_count_backend_rel_idx_tup_fetch(void); /* * Functions in pgstat_bgwriter.c diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out index faf73d956e8..35a0786d7b1 100644 --- a/src/test/regress/expected/rules.out +++ b/src/test/regress/expected/rules.out @@ -1850,8 +1850,9 @@ pg_stat_archiver| SELECT archived_count, pg_stat_backend| SELECT pid, seq_scan, seq_tup_read, + idx_tup_fetch, stats_reset - FROM pg_stat_get_backend_statistics(NULL::integer) s(pid, seq_scan, seq_tup_read, stats_reset); + FROM pg_stat_get_backend_statistics(NULL::integer) s(pid, seq_scan, seq_tup_read, idx_tup_fetch, stats_reset); pg_stat_bgwriter| SELECT pg_stat_get_bgwriter_buf_written_clean() AS buffers_clean, pg_stat_get_bgwriter_maxwritten_clean() AS maxwritten_clean, pg_stat_get_buf_alloc() AS buffers_alloc, diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out index c96d8d2ecae..9804cdc9c84 100644 --- a/src/test/regress/expected/stats.out +++ b/src/test/regress/expected/stats.out @@ -118,7 +118,8 @@ SELECT t.seq_scan, t.seq_tup_read, t.idx_scan, t.idx_tup_fetch, pg_catalog.pg_statio_user_tables AS b WHERE t.relname='tenk2' AND b.relname='tenk2'; COMMIT; -SELECT seq_scan AS seq_scan_before, seq_tup_read AS seq_tup_read_before +SELECT seq_scan AS seq_scan_before, seq_tup_read AS seq_tup_read_before, + idx_tup_fetch AS idx_tup_fetch_before FROM pg_stat_backend WHERE pid = pg_backend_pid() \gset -- test effects of TRUNCATE on n_live_tup/n_dead_tup counters CREATE TABLE trunc_stats_test(id serial); @@ -221,13 +222,15 @@ SELECT st.seq_scan >= pr.seq_scan + 1, t | t | t | t (1 row) -SELECT seq_scan AS seq_scan_after, seq_tup_read AS seq_tup_read_after +SELECT seq_scan AS seq_scan_after, seq_tup_read AS seq_tup_read_after, + idx_tup_fetch AS idx_tup_fetch_after FROM pg_stat_backend WHERE pid = pg_backend_pid() \gset SELECT :seq_scan_after > :seq_scan_before, - :seq_tup_read_after > :seq_tup_read_before; - ?column? | ?column? -----------+---------- - t | t + :seq_tup_read_after > :seq_tup_read_before, + :idx_tup_fetch_after > :idx_tup_fetch_before; + ?column? | ?column? | ?column? +----------+----------+---------- + t | t | t (1 row) SELECT st.heap_blks_read + st.heap_blks_hit >= pr.heap_blks + cl.relpages, diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql index 781b75d426a..279cb6f9dfb 100644 --- a/src/test/regress/sql/stats.sql +++ b/src/test/regress/sql/stats.sql @@ -38,7 +38,8 @@ SELECT t.seq_scan, t.seq_tup_read, t.idx_scan, t.idx_tup_fetch, WHERE t.relname='tenk2' AND b.relname='tenk2'; COMMIT; -SELECT seq_scan AS seq_scan_before, seq_tup_read AS seq_tup_read_before +SELECT seq_scan AS seq_scan_before, seq_tup_read AS seq_tup_read_before, + idx_tup_fetch AS idx_tup_fetch_before FROM pg_stat_backend WHERE pid = pg_backend_pid() \gset -- test effects of TRUNCATE on n_live_tup/n_dead_tup counters @@ -125,11 +126,13 @@ SELECT st.seq_scan >= pr.seq_scan + 1, FROM pg_stat_user_tables AS st, pg_class AS cl, prevstats AS pr WHERE st.relname='tenk2' AND cl.relname='tenk2'; -SELECT seq_scan AS seq_scan_after, seq_tup_read AS seq_tup_read_after +SELECT seq_scan AS seq_scan_after, seq_tup_read AS seq_tup_read_after, + idx_tup_fetch AS idx_tup_fetch_after FROM pg_stat_backend WHERE pid = pg_backend_pid() \gset SELECT :seq_scan_after > :seq_scan_before, - :seq_tup_read_after > :seq_tup_read_before; + :seq_tup_read_after > :seq_tup_read_before, + :idx_tup_fetch_after > :idx_tup_fetch_before; SELECT st.heap_blks_read + st.heap_blks_hit >= pr.heap_blks + cl.relpages, st.idx_blks_read + st.idx_blks_hit >= pr.idx_blks + 1 -- 2.34.1