This patch consists of two c functions to expose n_live_tuples and
n_dead_tuples, SQL functions to expose them to SQL land, and
corresponding fields added to pg_stat_all_tables.
This has been discussed in general. The purpose is to allow
autovacuum-esq conditional vacuuming and clustering using SQL to
discover the required stats.
-Glen Parker
--- ./src/backend/utils/adt/pgstatfuncs.c.old 2006-12-20 17:01:30.585852856
-0800
+++ ./src/backend/utils/adt/pgstatfuncs.c 2006-12-20 17:00:58.570719896
-0800
@@ -28,6 +28,8 @@
extern Datum pg_stat_get_tuples_inserted(PG_FUNCTION_ARGS);
extern Datum pg_stat_get_tuples_updated(PG_FUNCTION_ARGS);
extern Datum pg_stat_get_tuples_deleted(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_live_tuples(PG_FUNCTION_ARGS);
+extern Datum pg_stat_get_dead_tuples(PG_FUNCTION_ARGS);
extern Datum pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS);
extern Datum pg_stat_get_blocks_hit(PG_FUNCTION_ARGS);
extern Datum pg_stat_get_last_vacuum_time(PG_FUNCTION_ARGS);
@@ -153,6 +155,38 @@
Datum
+pg_stat_get_live_tuples(PG_FUNCTION_ARGS)
+{
+ Oid relid = PG_GETARG_OID(0);
+ int64 result;
+ PgStat_StatTabEntry *tabentry;
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64) (tabentry->n_live_tuples);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
+pg_stat_get_dead_tuples(PG_FUNCTION_ARGS)
+{
+ Oid relid = PG_GETARG_OID(0);
+ int64 result;
+ PgStat_StatTabEntry *tabentry;
+
+ if ((tabentry = pgstat_fetch_stat_tabentry(relid)) == NULL)
+ result = 0;
+ else
+ result = (int64) (tabentry->n_dead_tuples);
+
+ PG_RETURN_INT64(result);
+}
+
+
+Datum
pg_stat_get_blocks_fetched(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
--- ./src/include/catalog/pg_proc.h.old 2006-12-06 10:06:47.000000000 -0800
+++ ./src/include/catalog/pg_proc.h 2006-12-20 17:09:32.874533832 -0800
@@ -2872,6 +2872,10 @@
DESCR("Statistics: Number of tuples updated");
DATA(insert OID = 1933 ( pg_stat_get_tuples_deleted PGNSP PGUID 12 f f t f
s 1 20 "26" _null_ _null_ _null_ pg_stat_get_tuples_deleted - _null_ ));
DESCR("Statistics: Number of tuples deleted");
+DATA(insert OID = 2878 ( pg_stat_get_live_tuples PGNSP PGUID 12 f f t f
s 1 20 "26" _null_ _null_ _null_ pg_stat_get_live_tuples - _null_ ));
+DESCR("Statistics: Number of live tuples");
+DATA(insert OID = 2879 ( pg_stat_get_dead_tuples PGNSP PGUID 12 f f t f
s 1 20 "26" _null_ _null_ _null_ pg_stat_get_dead_tuples - _null_ ));
+DESCR("Statistics: Number of dead tuples");
DATA(insert OID = 1934 ( pg_stat_get_blocks_fetched PGNSP PGUID 12 f f t f
s 1 20 "26" _null_ _null_ _null_ pg_stat_get_blocks_fetched - _null_ ));
DESCR("Statistics: Number of blocks fetched");
DATA(insert OID = 1935 ( pg_stat_get_blocks_hit PGNSP PGUID 12
f f t f s 1 20 "26" _null_ _null_ _null_ pg_stat_get_blocks_hit - _null_ ));
--- ./src/backend/catalog/system_views.sql.old 2006-12-06 10:06:47.000000000
-0800
+++ ./src/backend/catalog/system_views.sql 2006-12-20 17:13:03.036584344
-0800
@@ -203,10 +203,12 @@
pg_stat_get_tuples_returned(C.oid) AS seq_tup_read,
sum(pg_stat_get_numscans(I.indexrelid))::bigint AS idx_scan,
sum(pg_stat_get_tuples_fetched(I.indexrelid))::bigint +
- pg_stat_get_tuples_fetched(C.oid) AS idx_tup_fetch,
+ pg_stat_get_tuples_fetched(C.oid) AS idx_tup_fetch,
pg_stat_get_tuples_inserted(C.oid) AS n_tup_ins,
pg_stat_get_tuples_updated(C.oid) AS n_tup_upd,
pg_stat_get_tuples_deleted(C.oid) AS n_tup_del,
+ pg_stat_get_live_tuples(C.oid) AS n_live_tup,
+ pg_stat_get_dead_tuples(C.oid) AS n_dead_tup,
pg_stat_get_last_vacuum_time(C.oid) as last_vacuum,
pg_stat_get_last_autovacuum_time(C.oid) as last_autovacuum,
pg_stat_get_last_analyze_time(C.oid) as last_analyze,
---------------------------(end of broadcast)---------------------------
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