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|
--
-- Statement level tracking
--
SET pg_stat_statements.track_utility = TRUE;
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
-- DO block - top-level tracking.
CREATE TABLE stats_track_tab (x int);
SET pg_stat_statements.track = 'top';
DELETE FROM stats_track_tab;
DO $$
BEGIN
DELETE FROM stats_track_tab;
END;
$$ LANGUAGE plpgsql;
SELECT toplevel, calls, query FROM pg_stat_statements
WHERE query LIKE '%DELETE%' ORDER BY query COLLATE "C", toplevel;
toplevel | calls | query
----------+-------+--------------------------------
t | 1 | DELETE FROM stats_track_tab
t | 1 | DO $$ +
| | BEGIN +
| | DELETE FROM stats_track_tab;+
| | END; +
| | $$ LANGUAGE plpgsql
(2 rows)
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
-- DO block - all-level tracking.
SET pg_stat_statements.track = 'all';
DELETE FROM stats_track_tab;
DO $$
BEGIN
DELETE FROM stats_track_tab;
END; $$;
DO LANGUAGE plpgsql $$
BEGIN
-- this is a SELECT
PERFORM 'hello world'::TEXT;
END; $$;
SELECT toplevel, calls, query FROM pg_stat_statements
ORDER BY query COLLATE "C", toplevel;
toplevel | calls | query
----------+-------+----------------------------------------------------
f | 1 | DELETE FROM stats_track_tab
t | 1 | DELETE FROM stats_track_tab
t | 1 | DO $$ +
| | BEGIN +
| | DELETE FROM stats_track_tab; +
| | END; $$
t | 1 | DO LANGUAGE plpgsql $$ +
| | BEGIN +
| | -- this is a SELECT +
| | PERFORM 'hello world'::TEXT; +
| | END; $$
f | 1 | SELECT $1::TEXT
t | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
t | 1 | SET pg_stat_statements.track = 'all'
(7 rows)
-- DO block - top-level tracking without utility.
SET pg_stat_statements.track = 'top';
SET pg_stat_statements.track_utility = FALSE;
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
DELETE FROM stats_track_tab;
DO $$
BEGIN
DELETE FROM stats_track_tab;
END; $$;
DO LANGUAGE plpgsql $$
BEGIN
-- this is a SELECT
PERFORM 'hello world'::TEXT;
END; $$;
SELECT toplevel, calls, query FROM pg_stat_statements
ORDER BY query COLLATE "C", toplevel;
toplevel | calls | query
----------+-------+----------------------------------------------------
t | 1 | DELETE FROM stats_track_tab
t | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
(2 rows)
-- DO block - all-level tracking without utility.
SET pg_stat_statements.track = 'all';
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
DELETE FROM stats_track_tab;
DO $$
BEGIN
DELETE FROM stats_track_tab;
END; $$;
DO LANGUAGE plpgsql $$
BEGIN
-- this is a SELECT
PERFORM 'hello world'::TEXT;
END; $$;
SELECT toplevel, calls, query FROM pg_stat_statements
ORDER BY query COLLATE "C", toplevel;
toplevel | calls | query
----------+-------+----------------------------------------------------
f | 1 | DELETE FROM stats_track_tab
t | 1 | DELETE FROM stats_track_tab
f | 1 | SELECT $1::TEXT
t | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
(4 rows)
-- PL/pgSQL function - top-level tracking.
SET pg_stat_statements.track = 'top';
SET pg_stat_statements.track_utility = FALSE;
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
CREATE FUNCTION PLUS_TWO(i INTEGER) RETURNS INTEGER AS $$
DECLARE
r INTEGER;
BEGIN
SELECT (i + 1 + 1.0)::INTEGER INTO r;
RETURN r;
END; $$ LANGUAGE plpgsql;
SELECT PLUS_TWO(3);
plus_two
----------
5
(1 row)
SELECT PLUS_TWO(7);
plus_two
----------
9
(1 row)
-- SQL function --- use LIMIT to keep it from being inlined
CREATE FUNCTION PLUS_ONE(i INTEGER) RETURNS INTEGER AS
$$ SELECT (i + 1.0)::INTEGER LIMIT 1 $$ LANGUAGE SQL;
SELECT PLUS_ONE(8);
plus_one
----------
9
(1 row)
SELECT PLUS_ONE(10);
plus_one
----------
11
(1 row)
SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
calls | rows | query
-------+------+----------------------------------------------------
2 | 2 | SELECT PLUS_ONE($1)
2 | 2 | SELECT PLUS_TWO($1)
1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
(3 rows)
-- immutable SQL function --- can be executed at plan time
CREATE FUNCTION PLUS_THREE(i INTEGER) RETURNS INTEGER AS
$$ SELECT i + 3 LIMIT 1 $$ IMMUTABLE LANGUAGE SQL;
SELECT PLUS_THREE(8);
plus_three
------------
11
(1 row)
SELECT PLUS_THREE(10);
plus_three
------------
13
(1 row)
SELECT toplevel, calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
toplevel | calls | rows | query
----------+-------+------+------------------------------------------------------------------------------
t | 2 | 2 | SELECT PLUS_ONE($1)
t | 2 | 2 | SELECT PLUS_THREE($1)
t | 2 | 2 | SELECT PLUS_TWO($1)
t | 1 | 3 | SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C"
t | 1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
(5 rows)
-- PL/pgSQL function - all-level tracking.
SET pg_stat_statements.track = 'all';
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
-- we drop and recreate the functions to avoid any caching funnies
DROP FUNCTION PLUS_ONE(INTEGER);
DROP FUNCTION PLUS_TWO(INTEGER);
DROP FUNCTION PLUS_THREE(INTEGER);
-- PL/pgSQL function
CREATE FUNCTION PLUS_TWO(i INTEGER) RETURNS INTEGER AS $$
DECLARE
r INTEGER;
BEGIN
SELECT (i + 1 + 1.0)::INTEGER INTO r;
RETURN r;
END; $$ LANGUAGE plpgsql;
SELECT PLUS_TWO(-1);
plus_two
----------
1
(1 row)
SELECT PLUS_TWO(2);
plus_two
----------
4
(1 row)
-- SQL function --- use LIMIT to keep it from being inlined
CREATE FUNCTION PLUS_ONE(i INTEGER) RETURNS INTEGER AS
$$ SELECT (i + 1.0)::INTEGER LIMIT 1 $$ LANGUAGE SQL;
SELECT PLUS_ONE(3);
plus_one
----------
4
(1 row)
SELECT PLUS_ONE(1);
plus_one
----------
2
(1 row)
SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
calls | rows | query
-------+------+----------------------------------------------------
2 | 2 | SELECT (i + $2 + $3)::INTEGER
2 | 2 | SELECT (i + $2)::INTEGER LIMIT $3
2 | 2 | SELECT PLUS_ONE($1)
2 | 2 | SELECT PLUS_TWO($1)
1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
(5 rows)
-- immutable SQL function --- can be executed at plan time
CREATE FUNCTION PLUS_THREE(i INTEGER) RETURNS INTEGER AS
$$ SELECT i + 3 LIMIT 1 $$ IMMUTABLE LANGUAGE SQL;
SELECT PLUS_THREE(8);
plus_three
------------
11
(1 row)
SELECT PLUS_THREE(10);
plus_three
------------
13
(1 row)
SELECT toplevel, calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
toplevel | calls | rows | query
----------+-------+------+------------------------------------------------------------------------------
f | 2 | 2 | SELECT (i + $2 + $3)::INTEGER
f | 2 | 2 | SELECT (i + $2)::INTEGER LIMIT $3
t | 2 | 2 | SELECT PLUS_ONE($1)
t | 2 | 2 | SELECT PLUS_THREE($1)
t | 2 | 2 | SELECT PLUS_TWO($1)
t | 1 | 5 | SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C"
f | 2 | 2 | SELECT i + $2 LIMIT $3
t | 1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
(8 rows)
--
-- pg_stat_statements.track = none
--
SET pg_stat_statements.track = 'none';
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
SELECT 1 AS "one";
one
-----
1
(1 row)
SELECT 1 + 1 AS "two";
two
-----
2
(1 row)
SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
calls | rows | query
-------+------+-------
(0 rows)
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
t
---
t
(1 row)
|
