-- -- DMLs on test table -- SET pg_stat_statements.track_utility = FALSE; CREATE TEMP TABLE pgss_dml_tab (a int, b char(20)); INSERT INTO pgss_dml_tab VALUES(generate_series(1, 10), 'aaa'); UPDATE pgss_dml_tab SET b = 'bbb' WHERE a > 7; DELETE FROM pgss_dml_tab WHERE a > 9; -- explicit transaction BEGIN; UPDATE pgss_dml_tab SET b = '111' WHERE a = 1 ; COMMIT; BEGIN \; UPDATE pgss_dml_tab SET b = '222' WHERE a = 2 \; COMMIT ; UPDATE pgss_dml_tab SET b = '333' WHERE a = 3 \; UPDATE pgss_dml_tab SET b = '444' WHERE a = 4 ; BEGIN \; UPDATE pgss_dml_tab SET b = '555' WHERE a = 5 \; UPDATE pgss_dml_tab SET b = '666' WHERE a = 6 \; COMMIT ; -- many INSERT values INSERT INTO pgss_dml_tab (a, b) VALUES (1, 'a'), (2, 'b'), (3, 'c'); -- SELECT with constants SELECT * FROM pgss_dml_tab WHERE a > 5 ORDER BY a ; a | b ---+---------------------- 6 | 666 7 | aaa 8 | bbb 9 | bbb (4 rows) SELECT * FROM pgss_dml_tab WHERE a > 9 ORDER BY a ; a | b ---+--- (0 rows) -- these two need to be done on a different table -- SELECT without constants SELECT * FROM pgss_dml_tab ORDER BY a; a | b ---+---------------------- 1 | a 1 | 111 2 | b 2 | 222 3 | c 3 | 333 4 | 444 5 | 555 6 | 666 7 | aaa 8 | bbb 9 | bbb (12 rows) -- SELECT with IN clause SELECT * FROM pgss_dml_tab WHERE a IN (1, 2, 3, 4, 5); a | b ---+---------------------- 1 | 111 2 | 222 3 | 333 4 | 444 5 | 555 1 | a 2 | b 3 | c (8 rows) SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C"; calls | rows | query -------+------+--------------------------------------------------------------------- 1 | 1 | DELETE FROM pgss_dml_tab WHERE a > $1 1 | 3 | INSERT INTO pgss_dml_tab (a, b) VALUES ($1, $2), ($3, $4), ($5, $6) 1 | 10 | INSERT INTO pgss_dml_tab VALUES(generate_series($1, $2), $3) 1 | 12 | SELECT * FROM pgss_dml_tab ORDER BY a 2 | 4 | SELECT * FROM pgss_dml_tab WHERE a > $1 ORDER BY a 1 | 8 | SELECT * FROM pgss_dml_tab WHERE a IN ($1, $2, $3, $4, $5) 1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t 1 | 0 | SET pg_stat_statements.track_utility = FALSE 6 | 6 | UPDATE pgss_dml_tab SET b = $1 WHERE a = $2 1 | 3 | UPDATE pgss_dml_tab SET b = $1 WHERE a > $2 (10 rows) SELECT pg_stat_statements_reset() IS NOT NULL AS t; t --- t (1 row) -- MERGE MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4) WHEN MATCHED THEN UPDATE SET b = st.b || st.a::text; MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4) WHEN MATCHED THEN UPDATE SET b = pgss_dml_tab.b || st.a::text; MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4) WHEN MATCHED AND length(st.b) > 1 THEN UPDATE SET b = pgss_dml_tab.b || st.a::text; MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) WHEN NOT MATCHED THEN INSERT (a, b) VALUES (0, NULL); MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) WHEN NOT MATCHED THEN INSERT VALUES (0, NULL); -- same as above MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) WHEN NOT MATCHED THEN INSERT (b, a) VALUES (NULL, 0); MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) WHEN NOT MATCHED THEN INSERT (a) VALUES (0); MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4) WHEN MATCHED THEN DELETE; MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4) WHEN MATCHED THEN DO NOTHING; MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4) WHEN NOT MATCHED THEN DO NOTHING; DROP TABLE pgss_dml_tab; SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C"; calls | rows | query -------+------+----------------------------------------------------------------------------------------- 1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+ | | WHEN MATCHED AND length(st.b) > $2 THEN UPDATE SET b = pgss_dml_tab.b || st.a::text 1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+ | | WHEN MATCHED THEN DELETE 1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+ | | WHEN MATCHED THEN DO NOTHING 1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+ | | WHEN MATCHED THEN UPDATE SET b = pgss_dml_tab.b || st.a::text 1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+ | | WHEN MATCHED THEN UPDATE SET b = st.b || st.a::text 1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+ | | WHEN NOT MATCHED THEN DO NOTHING 1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) + | | WHEN NOT MATCHED THEN INSERT (a) VALUES ($1) 2 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) + | | WHEN NOT MATCHED THEN INSERT (a, b) VALUES ($1, $2) 1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) + | | WHEN NOT MATCHED THEN INSERT (b, a) VALUES ($1, $2) 1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t (10 rows) -- check that [temp] table relation extensions are tracked as writes CREATE TABLE pgss_extend_tab (a int, b text); CREATE TEMP TABLE pgss_extend_temp_tab (a int, b text); SELECT pg_stat_statements_reset() IS NOT NULL AS t; t --- t (1 row) INSERT INTO pgss_extend_tab (a, b) SELECT generate_series(1, 1000), 'something'; INSERT INTO pgss_extend_temp_tab (a, b) SELECT generate_series(1, 1000), 'something'; WITH sizes AS ( SELECT pg_relation_size('pgss_extend_tab') / current_setting('block_size')::int8 AS rel_size, pg_relation_size('pgss_extend_temp_tab') / current_setting('block_size')::int8 AS temp_rel_size ) SELECT SUM(local_blks_written) >= (SELECT temp_rel_size FROM sizes) AS temp_written_ok, SUM(local_blks_dirtied) >= (SELECT temp_rel_size FROM sizes) AS temp_dirtied_ok, SUM(shared_blks_written) >= (SELECT rel_size FROM sizes) AS written_ok, SUM(shared_blks_dirtied) >= (SELECT rel_size FROM sizes) AS dirtied_ok FROM pg_stat_statements; temp_written_ok | temp_dirtied_ok | written_ok | dirtied_ok -----------------+-----------------+------------+------------ t | t | t | t (1 row) SELECT pg_stat_statements_reset() IS NOT NULL AS t; t --- t (1 row)