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dc68515968
This is a continuation of work like11c34b342b, done to reduce the bloat of pg_stat_statements by applying more normalization to query entries. This commit is able to detect and normalize values in VariableSetStmt, resulting in: SET conf_param = $1 Compared to other parse nodes, VariableSetStmt is embedded in much more places in the parser, impacting many query patterns in pg_stat_statements. A custom jumble function is used, with an extra field in the node to decide if arguments should be included in the jumbling or not, a location field being not enough for this purpose. This approach allows for a finer tuning. Clauses relying on one or more keywords are not normalized, for example: * DEFAULT * FROM CURRENT * List of keywords. SET SESSION CHARACTERISTICS AS TRANSACTION, where it is critical to differentiate different sets of options, is a good example of why normalization should not happen. Some queries use VariableSetStmt for some subclauses with SET, that also have their values normalized: - ALTER DATABASE - ALTER ROLE - ALTER SYSTEM - CREATE/ALTER FUNCTIONba90eac7a9has added test coverage for most of the existing SET patterns. The expected output of these tests shows the difference this commit creates. Normalization could be perhaps applied to more portions of the grammar but what is done here is conservative, and good enough as a starting point. Author: Greg Sabino Mullane, Michael Paquier Discussion: https://postgr.es/m/36e5bffe-e989-194f-85c8-06e7bc88e6f7@amazon.com Discussion: https://postgr.es/m/B44FA29D-EBD0-4DD9-ABC2-16F1CB087074@amazon.com Discussion: https://postgr.es/m/CAKAnmmJtJY2jzQN91=2QAD2eAJAA-Per61eyO48-TyxEg-q0Rg@mail.gmail.com
175 lines
7.2 KiB
Plaintext
175 lines
7.2 KiB
Plaintext
--
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-- DMLs on test table
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--
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SET pg_stat_statements.track_utility = FALSE;
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CREATE TEMP TABLE pgss_dml_tab (a int, b char(20));
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INSERT INTO pgss_dml_tab VALUES(generate_series(1, 10), 'aaa');
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UPDATE pgss_dml_tab SET b = 'bbb' WHERE a > 7;
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DELETE FROM pgss_dml_tab WHERE a > 9;
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-- explicit transaction
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BEGIN;
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UPDATE pgss_dml_tab SET b = '111' WHERE a = 1 ;
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COMMIT;
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BEGIN \;
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UPDATE pgss_dml_tab SET b = '222' WHERE a = 2 \;
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COMMIT ;
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UPDATE pgss_dml_tab SET b = '333' WHERE a = 3 \;
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UPDATE pgss_dml_tab SET b = '444' WHERE a = 4 ;
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BEGIN \;
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UPDATE pgss_dml_tab SET b = '555' WHERE a = 5 \;
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UPDATE pgss_dml_tab SET b = '666' WHERE a = 6 \;
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COMMIT ;
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-- many INSERT values
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INSERT INTO pgss_dml_tab (a, b) VALUES (1, 'a'), (2, 'b'), (3, 'c');
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-- SELECT with constants
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SELECT * FROM pgss_dml_tab WHERE a > 5 ORDER BY a ;
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a | b
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---+----------------------
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6 | 666
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7 | aaa
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8 | bbb
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9 | bbb
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(4 rows)
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SELECT *
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FROM pgss_dml_tab
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WHERE a > 9
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ORDER BY a ;
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a | b
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---+---
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(0 rows)
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-- these two need to be done on a different table
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-- SELECT without constants
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SELECT * FROM pgss_dml_tab ORDER BY a;
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a | b
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---+----------------------
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1 | a
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1 | 111
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2 | b
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2 | 222
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3 | c
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3 | 333
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4 | 444
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5 | 555
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6 | 666
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7 | aaa
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8 | bbb
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9 | bbb
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(12 rows)
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-- SELECT with IN clause
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SELECT * FROM pgss_dml_tab WHERE a IN (1, 2, 3, 4, 5);
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a | b
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---+----------------------
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1 | 111
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2 | 222
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3 | 333
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4 | 444
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5 | 555
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1 | a
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2 | b
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3 | c
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(8 rows)
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SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
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calls | rows | query
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-------+------+---------------------------------------------------------------------
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1 | 1 | DELETE FROM pgss_dml_tab WHERE a > $1
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1 | 3 | INSERT INTO pgss_dml_tab (a, b) VALUES ($1, $2), ($3, $4), ($5, $6)
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1 | 10 | INSERT INTO pgss_dml_tab VALUES(generate_series($1, $2), $3)
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1 | 12 | SELECT * FROM pgss_dml_tab ORDER BY a
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2 | 4 | SELECT * FROM pgss_dml_tab WHERE a > $1 ORDER BY a
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1 | 8 | SELECT * FROM pgss_dml_tab WHERE a IN ($1, $2, $3, $4, $5)
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1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
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1 | 0 | SET pg_stat_statements.track_utility = $1
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6 | 6 | UPDATE pgss_dml_tab SET b = $1 WHERE a = $2
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1 | 3 | UPDATE pgss_dml_tab SET b = $1 WHERE a > $2
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(10 rows)
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SELECT pg_stat_statements_reset() IS NOT NULL AS t;
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t
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---
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t
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(1 row)
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-- MERGE
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4)
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WHEN MATCHED THEN UPDATE SET b = st.b || st.a::text;
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4)
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WHEN MATCHED THEN UPDATE SET b = pgss_dml_tab.b || st.a::text;
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4)
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WHEN MATCHED AND length(st.b) > 1 THEN UPDATE SET b = pgss_dml_tab.b || st.a::text;
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a)
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WHEN NOT MATCHED THEN INSERT (a, b) VALUES (0, NULL);
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a)
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WHEN NOT MATCHED THEN INSERT VALUES (0, NULL); -- same as above
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a)
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WHEN NOT MATCHED THEN INSERT (b, a) VALUES (NULL, 0);
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a)
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WHEN NOT MATCHED THEN INSERT (a) VALUES (0);
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4)
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WHEN MATCHED THEN DELETE;
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4)
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WHEN MATCHED THEN DO NOTHING;
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MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= 4)
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WHEN NOT MATCHED THEN DO NOTHING;
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DROP TABLE pgss_dml_tab;
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SELECT calls, rows, query FROM pg_stat_statements ORDER BY query COLLATE "C";
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calls | rows | query
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-------+------+-----------------------------------------------------------------------------------------
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1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+
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| | WHEN MATCHED AND length(st.b) > $2 THEN UPDATE SET b = pgss_dml_tab.b || st.a::text
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1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+
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| | WHEN MATCHED THEN DELETE
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1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+
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| | WHEN MATCHED THEN DO NOTHING
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1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+
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| | WHEN MATCHED THEN UPDATE SET b = pgss_dml_tab.b || st.a::text
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1 | 6 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+
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| | WHEN MATCHED THEN UPDATE SET b = st.b || st.a::text
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1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a AND st.a >= $1)+
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| | WHEN NOT MATCHED THEN DO NOTHING
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1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) +
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| | WHEN NOT MATCHED THEN INSERT (a) VALUES ($1)
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2 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) +
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| | WHEN NOT MATCHED THEN INSERT (a, b) VALUES ($1, $2)
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1 | 0 | MERGE INTO pgss_dml_tab USING pgss_dml_tab st ON (st.a = pgss_dml_tab.a) +
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| | WHEN NOT MATCHED THEN INSERT (b, a) VALUES ($1, $2)
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1 | 1 | SELECT pg_stat_statements_reset() IS NOT NULL AS t
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(10 rows)
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-- check that [temp] table relation extensions are tracked as writes
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CREATE TABLE pgss_extend_tab (a int, b text);
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CREATE TEMP TABLE pgss_extend_temp_tab (a int, b text);
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SELECT pg_stat_statements_reset() IS NOT NULL AS t;
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t
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---
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t
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(1 row)
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INSERT INTO pgss_extend_tab (a, b) SELECT generate_series(1, 1000), 'something';
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INSERT INTO pgss_extend_temp_tab (a, b) SELECT generate_series(1, 1000), 'something';
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WITH sizes AS (
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SELECT
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pg_relation_size('pgss_extend_tab') / current_setting('block_size')::int8 AS rel_size,
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pg_relation_size('pgss_extend_temp_tab') / current_setting('block_size')::int8 AS temp_rel_size
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)
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SELECT
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SUM(local_blks_written) >= (SELECT temp_rel_size FROM sizes) AS temp_written_ok,
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SUM(local_blks_dirtied) >= (SELECT temp_rel_size FROM sizes) AS temp_dirtied_ok,
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SUM(shared_blks_written) >= (SELECT rel_size FROM sizes) AS written_ok,
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SUM(shared_blks_dirtied) >= (SELECT rel_size FROM sizes) AS dirtied_ok
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FROM pg_stat_statements;
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temp_written_ok | temp_dirtied_ok | written_ok | dirtied_ok
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-----------------+-----------------+------------+------------
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t | t | t | t
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(1 row)
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SELECT pg_stat_statements_reset() IS NOT NULL AS t;
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t
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---
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t
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(1 row)
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