v4-0003-Machinery-for-grabbing-an-extended-vacuum-statistics.patch

From 5fe3cb2abf25ec64eb43ecf6b70885183a89fe2b Mon Sep 17 00:00:00 2001
From: Alena Rybakina <a.rybakina@postgrespro.ru>
Date: Tue, 11 Jun 2024 13:55:39 +0300
Subject: [PATCH 4/4] Machinery for grabbing an extended vacuum statistics on
 databases. It transmits vacuum statistical information about each table and
 accumulates it for the database which the table belonged.

---
 src/backend/catalog/system_views.sql          | 27 +++++++
 src/backend/utils/activity/pgstat.c           |  2 +
 src/backend/utils/activity/pgstat_database.c  |  1 +
 src/backend/utils/activity/pgstat_relation.c  | 16 ++++
 src/backend/utils/adt/pgstatfuncs.c           | 79 +++++++++++++++++++
 src/include/catalog/pg_proc.dat               |  9 +++
 src/include/pgstat.h                          |  3 +-
 src/test/regress/expected/opr_sanity.out      |  7 +-
 src/test/regress/expected/rules.out           | 17 ++++
 ...ut => vacuum_tables_and_db_statistics.out} | 78 ++++++++++++++++++
 src/test/regress/parallel_schedule            |  2 +-
 ...ql => vacuum_tables_and_db_statistics.sql} | 66 +++++++++++++++-
 12 files changed, 301 insertions(+), 6 deletions(-)
 rename src/test/regress/expected/{vacuum_tables_statistics.out => vacuum_tables_and_db_statistics.out} (76%)
 rename src/test/regress/sql/{vacuum_tables_statistics.sql => vacuum_tables_and_db_statistics.sql} (77%)

diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 05f8fc07108..1b60f0dd81a 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1466,3 +1466,30 @@ WHERE
   rel.oid = stats.relid AND
   ns.oid = rel.relnamespace;
 
+CREATE VIEW pg_stat_vacuum_database AS
+SELECT
+  db.oid as dboid,
+
+  stats.db_blks_read,
+  stats.db_blks_hit,
+  stats.total_blks_dirtied,
+  stats.total_blks_written,
+
+  stats.wal_records,
+  stats.wal_fpi,
+  stats.wal_bytes,
+
+  stats.blk_read_time,
+  stats.blk_write_time,
+
+  stats.delay_time,
+  stats.system_time,
+  stats.user_time,
+  stats.total_time,
+
+  stats.interrupts
+FROM
+  pg_database db LEFT JOIN pg_stat_vacuum_database(db.oid) stats
+ON
+  db.oid = stats.dboid;
+
diff --git a/src/backend/utils/activity/pgstat.c b/src/backend/utils/activity/pgstat.c
index 75890b18988..3c50bea379c 100644
--- a/src/backend/utils/activity/pgstat.c
+++ b/src/backend/utils/activity/pgstat.c
@@ -1099,6 +1099,8 @@ pgstat_update_snapshot(PgStat_Kind kind)
 		pgstat_fetch_consistency = PGSTAT_FETCH_CONSISTENCY_SNAPSHOT;
 		if (kind == PGSTAT_KIND_RELATION)
 			pgstat_build_snapshot(PGSTAT_KIND_RELATION);
+		else if (kind == PGSTAT_KIND_DATABASE)
+			pgstat_build_snapshot(PGSTAT_KIND_DATABASE);
 	}
 	PG_FINALLY();
 	{
diff --git a/src/backend/utils/activity/pgstat_database.c b/src/backend/utils/activity/pgstat_database.c
index 29bc0909748..a060d1a4042 100644
--- a/src/backend/utils/activity/pgstat_database.c
+++ b/src/backend/utils/activity/pgstat_database.c
@@ -430,6 +430,7 @@ pgstat_database_flush_cb(PgStat_EntryRef *entry_ref, bool nowait)
 	pgstat_unlock_entry(entry_ref);
 
 	memset(pendingent, 0, sizeof(*pendingent));
+	memset(&(pendingent)->vacuum_ext, 0, sizeof(ExtVacReport));
 
 	return true;
 }
diff --git a/src/backend/utils/activity/pgstat_relation.c b/src/backend/utils/activity/pgstat_relation.c
index 5b06b04faad..cc09aba571f 100644
--- a/src/backend/utils/activity/pgstat_relation.c
+++ b/src/backend/utils/activity/pgstat_relation.c
@@ -217,6 +217,7 @@ pgstat_report_vacuum_error(Oid tableoid, ExtVacReportType m_type)
 	PgStatShared_Relation *shtabentry;
 	PgStat_StatTabEntry *tabentry;
 	Oid			dboid =  MyDatabaseId;
+	PgStat_StatDBEntry *dbentry;	/* pending database entry */
 
 	if (!pgstat_track_counts)
 		return;
@@ -230,6 +231,10 @@ pgstat_report_vacuum_error(Oid tableoid, ExtVacReportType m_type)
 	tabentry->vacuum_ext.interrupts++;
 	tabentry->vacuum_ext.type = m_type;
 	pgstat_unlock_entry(entry_ref);
+
+	dbentry = pgstat_prep_database_pending(dboid);
+	dbentry->vacuum_ext.interrupts++;
+	dbentry->vacuum_ext.type = m_type;
 }
 
 /*
@@ -243,6 +248,7 @@ pgstat_report_vacuum(Oid tableoid, bool shared,
 	PgStat_EntryRef *entry_ref;
 	PgStatShared_Relation *shtabentry;
 	PgStat_StatTabEntry *tabentry;
+	PgStatShared_Database *dbentry;
 	Oid			dboid = (shared ? InvalidOid : MyDatabaseId);
 	TimestampTz ts;
 
@@ -296,6 +302,16 @@ pgstat_report_vacuum(Oid tableoid, bool shared,
 	 * VACUUM command has processed all tables and committed.
 	 */
 	pgstat_flush_io(false);
+	if (dboid != InvalidOid)
+	{
+		entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_DATABASE,
+											dboid, InvalidOid, false);
+		dbentry = (PgStatShared_Database *) entry_ref->shared_stats;
+
+		pgstat_accumulate_extvac_stats(&dbentry->stats.vacuum_ext, params, false);
+		pgstat_unlock_entry(entry_ref);
+	}
+
 }
 
 /*
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index b868b917ceb..0c490ba5f1a 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -2036,6 +2036,7 @@ pg_stat_have_stats(PG_FUNCTION_ARGS)
 
 #define EXTVACHEAPSTAT_COLUMNS	27
 #define EXTVACIDXSTAT_COLUMNS	19
+#define EXTVACDBSTAT_COLUMNS	15
 #define EXTVACSTAT_COLUMNS Max(EXTVACHEAPSTAT_COLUMNS, EXTVACIDXSTAT_COLUMNS)
 
 static Oid CurrentDatabaseId = InvalidOid;
@@ -2076,6 +2077,48 @@ fetch_dbstat_tabentry(Oid dbid, Oid relid)
 	return tabentry;
 }
 
+static void
+tuplestore_put_for_database(Oid dbid, Tuplestorestate *tupstore,
+			   TupleDesc tupdesc, PgStatShared_Database *dbentry, int ncolumns)
+{
+	Datum		values[EXTVACDBSTAT_COLUMNS];
+	bool		nulls[EXTVACDBSTAT_COLUMNS];
+	char		buf[256];
+	int			i = 0;
+
+	memset(nulls, 0, EXTVACDBSTAT_COLUMNS * sizeof(bool));
+
+	values[i++] = ObjectIdGetDatum(dbid);
+
+	values[i++] = Int64GetDatum(dbentry->stats.vacuum_ext.total_blks_read);
+	values[i++] = Int64GetDatum(dbentry->stats.vacuum_ext.total_blks_hit);
+	values[i++] = Int64GetDatum(dbentry->stats.vacuum_ext.total_blks_dirtied);
+	values[i++] = Int64GetDatum(dbentry->stats.vacuum_ext.total_blks_written);
+
+	values[i++] = Int64GetDatum(dbentry->stats.vacuum_ext.wal_records);
+	values[i++] = Int64GetDatum(dbentry->stats.vacuum_ext.wal_fpi);
+
+	/* Convert to numeric, like pg_stat_statements */
+	snprintf(buf, sizeof buf, UINT64_FORMAT, dbentry->stats.vacuum_ext.wal_bytes);
+	values[i++] = DirectFunctionCall3(numeric_in,
+									  CStringGetDatum(buf),
+									  ObjectIdGetDatum(0),
+									  Int32GetDatum(-1));
+
+	values[i++] = Float8GetDatum(dbentry->stats.vacuum_ext.blk_read_time);
+	values[i++] = Float8GetDatum(dbentry->stats.vacuum_ext.blk_write_time);
+	values[i++] = Float8GetDatum(dbentry->stats.vacuum_ext.delay_time);
+	values[i++] = Float8GetDatum(dbentry->stats.vacuum_ext.system_time);
+	values[i++] = Float8GetDatum(dbentry->stats.vacuum_ext.user_time);
+	values[i++] = Float8GetDatum(dbentry->stats.vacuum_ext.total_time);
+	values[i++] = Int32GetDatum(dbentry->stats.vacuum_ext.interrupts);
+
+
+	Assert(i == ncolumns);
+
+	tuplestore_putvalues(tupstore, tupdesc, values, nulls);
+}
+
 static void
 tuplestore_put_for_relation(Oid relid, Tuplestorestate *tupstore,
 			   TupleDesc tupdesc, PgStat_StatTabEntry *tabentry, int ncolumns)
@@ -2220,6 +2263,31 @@ pg_stats_vacuum(FunctionCallInfo fcinfo, ExtVacReportType type, int ncolumns)
 			}
 		}
 	}
+	else if (type == PGSTAT_EXTVAC_DB)
+	{
+		PgStatShared_Database	   *dbentry;
+		PgStat_EntryRef 		   *entry_ref;
+		Oid						storedMyDatabaseId = MyDatabaseId;
+
+		pgstat_update_snapshot(PGSTAT_KIND_DATABASE);
+		MyDatabaseId = storedMyDatabaseId;
+
+		if (OidIsValid(dbid))
+		{
+			entry_ref = pgstat_get_entry_ref_locked(PGSTAT_KIND_DATABASE,
+											dbid, InvalidOid, false);
+			dbentry = (PgStatShared_Database *) entry_ref->shared_stats;
+
+			if (dbentry == NULL)
+				/* Table doesn't exist or isn't a heap relation */
+				PG_RETURN_NULL();
+
+			tuplestore_put_for_database(dbid, tupstore, tupdesc, dbentry, ncolumns);
+			pgstat_unlock_entry(entry_ref);
+		}
+		else
+			PG_RETURN_NULL();
+	}
 	PG_RETURN_NULL();
 }
 
@@ -2244,3 +2312,14 @@ pg_stat_vacuum_indexes(PG_FUNCTION_ARGS)
 
 	PG_RETURN_NULL();
 }
+
+/*
+ * Get the vacuum statistics for the database.
+ */
+Datum
+pg_stat_vacuum_database(PG_FUNCTION_ARGS)
+{
+		return pg_stats_vacuum(fcinfo, PGSTAT_EXTVAC_DB, EXTVACDBSTAT_COLUMNS);
+
+	PG_RETURN_NULL();
+}
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 6613d2775f9..8a8f21840c0 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -12264,4 +12264,13 @@
   proargmodes => '{i,i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
   proargnames => '{dboid,reloid,relid,total_blks_read,total_blks_hit,total_blks_dirtied,total_blks_written,rel_blks_read,rel_blks_hit,pages_deleted,tuples_deleted,wal_records,wal_fpi,wal_bytes,blk_read_time,blk_write_time,delay_time,system_time,user_time,total_time,interrupts}',
   prosrc => 'pg_stat_vacuum_indexes' }
+{ oid => '8003',
+  descr => 'pg_stat_vacuum_database return stats values',
+  proname => 'pg_stat_vacuum_database', provolatile => 's', prorettype => 'record',proisstrict => 'f',
+  proretset => 't',
+  proargtypes => 'oid',
+  proallargtypes => '{oid,oid,int8,int8,int8,int8,int8,int8,numeric,float8,float8,float8,float8,float8,float8,int4}',
+  proargmodes => '{i,o,o,o,o,o,o,o,o,o,o,o,o,o,o,o}',
+  proargnames => '{dbid,dboid,db_blks_read,db_blks_hit,total_blks_dirtied,total_blks_written,wal_records,wal_fpi,wal_bytes,blk_read_time,blk_write_time,delay_time,system_time,user_time,total_time,interrupts}',
+  prosrc => 'pg_stat_vacuum_database' },
 ]
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 762b53b88ed..110e9472f3c 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -173,7 +173,8 @@ typedef enum ExtVacReportType
 {
 	PGSTAT_EXTVAC_INVALID = 0,
 	PGSTAT_EXTVAC_HEAP = 1,
-	PGSTAT_EXTVAC_INDEX = 2
+	PGSTAT_EXTVAC_INDEX = 2,
+	PGSTAT_EXTVAC_DB = 3,
 } ExtVacReportType;
 
 /* ----------
diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index 1127c99177b..696602d974c 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -32,11 +32,12 @@ WHERE p1.prolang = 0 OR p1.prorettype = 0 OR
        prokind NOT IN ('f', 'a', 'w', 'p') OR
        provolatile NOT IN ('i', 's', 'v') OR
        proparallel NOT IN ('s', 'r', 'u');
- oid  |        proname         
-------+------------------------
+ oid  |         proname         
+------+-------------------------
  8001 | pg_stat_vacuum_tables
  8002 | pg_stat_vacuum_indexes
-(2 rows)
+ 8003 | pg_stat_vacuum_database
+(3 rows)
 
 -- prosrc should never be null; it can be empty only if prosqlbody isn't null
 SELECT p1.oid, p1.proname
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index bc56f352d14..51763846607 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2230,6 +2230,23 @@ pg_stat_user_tables| SELECT relid,
     autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (schemaname !~ '^pg_toast'::text));
+pg_stat_vacuum_database| SELECT db.oid AS dboid,
+    stats.db_blks_read,
+    stats.db_blks_hit,
+    stats.total_blks_dirtied,
+    stats.total_blks_written,
+    stats.wal_records,
+    stats.wal_fpi,
+    stats.wal_bytes,
+    stats.blk_read_time,
+    stats.blk_write_time,
+    stats.delay_time,
+    stats.system_time,
+    stats.user_time,
+    stats.total_time,
+    stats.interrupts
+   FROM (pg_database db
+     LEFT JOIN LATERAL pg_stat_vacuum_database(db.oid) stats(dboid, db_blks_read, db_blks_hit, total_blks_dirtied, total_blks_written, wal_records, wal_fpi, wal_bytes, blk_read_time, blk_write_time, delay_time, system_time, user_time, total_time, interrupts) ON ((db.oid = stats.dboid)));
 pg_stat_vacuum_indexes| SELECT rel.oid AS relid,
     ns.nspname AS schema,
     rel.relname,
diff --git a/src/test/regress/expected/vacuum_tables_statistics.out b/src/test/regress/expected/vacuum_tables_and_db_statistics.out
similarity index 76%
rename from src/test/regress/expected/vacuum_tables_statistics.out
rename to src/test/regress/expected/vacuum_tables_and_db_statistics.out
index b85a5cab9af..6146a27bdb5 100644
--- a/src/test/regress/expected/vacuum_tables_statistics.out
+++ b/src/test/regress/expected/vacuum_tables_and_db_statistics.out
@@ -6,6 +6,9 @@
 -- number of frozen and visible pages removed by backend.
 -- Statistic wal_fpi is not displayed in this test because its behavior is unstable.
 --
+CREATE DATABASE statistic_vacuum_database;
+CREATE DATABASE statistic_vacuum_database1;
+\c statistic_vacuum_database;
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
  track_counts 
@@ -196,4 +199,79 @@ FROM pg_stat_vacuum_tables WHERE relname = 'vestat';
  t            | t                 | t                    | t
 (1 row)
 
+-- Now check vacuum statistics for current database
+SELECT pg_database.datname,
+       db_blks_hit > 0 AS db_blks_hit,
+       total_blks_dirtied > 0 AS total_blks_dirtied,
+       total_blks_written > 0 AS total_blks_written,
+       wal_records > 0 AS wal_records,
+       wal_fpi > 0 AS wal_fpi,
+       wal_bytes > 0 AS wal_bytes,
+       user_time > 0 AS user_time,
+       total_time > 0 AS total_time
+FROM
+pg_stat_vacuum_database, pg_database
+WHERE pg_database.datname = current_database() and pg_database.oid = pg_stat_vacuum_database.dboid;
+          datname          | db_blks_hit | total_blks_dirtied | total_blks_written | wal_records | wal_fpi | wal_bytes | user_time | total_time 
+---------------------------+-------------+--------------------+--------------------+-------------+---------+-----------+-----------+------------
+ statistic_vacuum_database | t           | t                  | t                  | t           | t       | t         | t         | t
+(1 row)
+
+DROP TABLE vestat CASCADE;
+-- ensure pending stats are flushed
+SELECT pg_stat_force_next_flush();
+ pg_stat_force_next_flush 
+--------------------------
+ 
+(1 row)
+
+CREATE TABLE vestat (x int) WITH (autovacuum_enabled = off, fillfactor = 10);
+INSERT INTO vestat SELECT x FROM generate_series(1,:sample_size) as x;
+ANALYZE vestat;
+UPDATE vestat SET x = 10001;
+VACUUM (PARALLEL 0, BUFFER_USAGE_LIMIT 128) vestat;
+\c statistic_vacuum_database1;
+-- Now check vacuum statistics for postgres database from another database
+SELECT pg_database.datname,
+       db_blks_hit > 0 AS db_blks_hit,
+       total_blks_dirtied > 0 AS total_blks_dirtied,
+       total_blks_written > 0 AS total_blks_written,
+       wal_records > 0 AS wal_records,
+       wal_fpi > 0 AS wal_fpi,
+       wal_bytes > 0 AS wal_bytes,
+       user_time > 0 AS user_time,
+       total_time > 0 AS total_time
+FROM
+pg_stat_vacuum_database, pg_database
+WHERE pg_database.datname = 'statistic_vacuum_database' and pg_database.oid = pg_stat_vacuum_database.dboid;
+          datname          | db_blks_hit | total_blks_dirtied | total_blks_written | wal_records | wal_fpi | wal_bytes | user_time | total_time 
+---------------------------+-------------+--------------------+--------------------+-------------+---------+-----------+-----------+------------
+ statistic_vacuum_database | t           | t                  | t                  | t           | t       | t         | t         | t
+(1 row)
+
+\c statistic_vacuum_database
+RESET vacuum_freeze_min_age;
+RESET vacuum_freeze_table_age;
 DROP TABLE vestat CASCADE;
+\c statistic_vacuum_database1;
+SELECT count(*)
+FROM pg_database d
+CROSS JOIN pg_stat_vacuum_tables(d.oid, 0)
+WHERE oid = 0; -- must be 0
+ count 
+-------
+     0
+(1 row)
+
+SELECT count(*)
+FROM pg_database d
+CROSS JOIN pg_stat_vacuum_database(0)
+WHERE oid = 0; -- must be 0
+ count 
+-------
+     0
+(1 row)
+
+\c postgres
+DROP DATABASE statistic_vacuum_database1;
+DROP DATABASE statistic_vacuum_database;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index b9408a43f71..129b1102028 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -141,4 +141,4 @@ test: tablespace
 # Check vacuum statistics
 # ----------
 test: vacuum_index_statistics
-test: vacuum_tables_statistics
\ No newline at end of file
+test: vacuum_tables_and_db_statistics
\ No newline at end of file
diff --git a/src/test/regress/sql/vacuum_tables_statistics.sql b/src/test/regress/sql/vacuum_tables_and_db_statistics.sql
similarity index 77%
rename from src/test/regress/sql/vacuum_tables_statistics.sql
rename to src/test/regress/sql/vacuum_tables_and_db_statistics.sql
index 41e387dd304..da59acf604f 100644
--- a/src/test/regress/sql/vacuum_tables_statistics.sql
+++ b/src/test/regress/sql/vacuum_tables_and_db_statistics.sql
@@ -7,6 +7,10 @@
 -- Statistic wal_fpi is not displayed in this test because its behavior is unstable.
 --
 
+CREATE DATABASE statistic_vacuum_database;
+CREATE DATABASE statistic_vacuum_database1;
+\c statistic_vacuum_database;
+
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 -- not enabled by default, but we want to test it...
@@ -155,4 +159,64 @@ VACUUM (PARALLEL 0, BUFFER_USAGE_LIMIT 128) vestat;
 SELECT pages_frozen = :pf AS pages_frozen,pages_all_visible = :pv AS pages_all_visible,rev_all_frozen_pages = :hafp AS rev_all_frozen_pages,rev_all_visible_pages = :havp AS rev_all_visible_pages
 FROM pg_stat_vacuum_tables WHERE relname = 'vestat';
 
-DROP TABLE vestat CASCADE;
\ No newline at end of file
+-- Now check vacuum statistics for current database
+SELECT pg_database.datname,
+       db_blks_hit > 0 AS db_blks_hit,
+       total_blks_dirtied > 0 AS total_blks_dirtied,
+       total_blks_written > 0 AS total_blks_written,
+       wal_records > 0 AS wal_records,
+       wal_fpi > 0 AS wal_fpi,
+       wal_bytes > 0 AS wal_bytes,
+       user_time > 0 AS user_time,
+       total_time > 0 AS total_time
+FROM
+pg_stat_vacuum_database, pg_database
+WHERE pg_database.datname = current_database() and pg_database.oid = pg_stat_vacuum_database.dboid;
+
+DROP TABLE vestat CASCADE;
+
+-- ensure pending stats are flushed
+SELECT pg_stat_force_next_flush();
+
+CREATE TABLE vestat (x int) WITH (autovacuum_enabled = off, fillfactor = 10);
+INSERT INTO vestat SELECT x FROM generate_series(1,:sample_size) as x;
+ANALYZE vestat;
+UPDATE vestat SET x = 10001;
+VACUUM (PARALLEL 0, BUFFER_USAGE_LIMIT 128) vestat;
+
+\c statistic_vacuum_database1;
+
+-- Now check vacuum statistics for postgres database from another database
+SELECT pg_database.datname,
+       db_blks_hit > 0 AS db_blks_hit,
+       total_blks_dirtied > 0 AS total_blks_dirtied,
+       total_blks_written > 0 AS total_blks_written,
+       wal_records > 0 AS wal_records,
+       wal_fpi > 0 AS wal_fpi,
+       wal_bytes > 0 AS wal_bytes,
+       user_time > 0 AS user_time,
+       total_time > 0 AS total_time
+FROM
+pg_stat_vacuum_database, pg_database
+WHERE pg_database.datname = 'statistic_vacuum_database' and pg_database.oid = pg_stat_vacuum_database.dboid;
+
+\c statistic_vacuum_database
+
+RESET vacuum_freeze_min_age;
+RESET vacuum_freeze_table_age;
+DROP TABLE vestat CASCADE;
+
+\c statistic_vacuum_database1;
+SELECT count(*)
+FROM pg_database d
+CROSS JOIN pg_stat_vacuum_tables(d.oid, 0)
+WHERE oid = 0; -- must be 0
+
+SELECT count(*)
+FROM pg_database d
+CROSS JOIN pg_stat_vacuum_database(0)
+WHERE oid = 0; -- must be 0
+
+\c postgres
+DROP DATABASE statistic_vacuum_database1;
+DROP DATABASE statistic_vacuum_database;
-- 
2.34.1