3336 lines
117 KiB
Plaintext
3336 lines
117 KiB
Plaintext
-- Generic extended statistics support
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--
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-- Note: tables for which we check estimated row counts should be created
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-- with autovacuum_enabled = off, so that we don't have unstable results
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-- from auto-analyze happening when we didn't expect it.
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--
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-- check the number of estimated/actual rows in the top node
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create function check_estimated_rows(text) returns table (estimated int, actual int)
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language plpgsql as
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$$
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declare
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ln text;
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tmp text[];
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first_row bool := true;
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begin
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for ln in
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execute format('explain analyze %s', $1)
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loop
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if first_row then
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first_row := false;
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tmp := regexp_match(ln, 'rows=(\d*) .* rows=(\d*)');
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return query select tmp[1]::int, tmp[2]::int;
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end if;
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end loop;
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end;
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$$;
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-- Verify failures
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CREATE TABLE ext_stats_test (x text, y int, z int);
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CREATE STATISTICS tst;
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ERROR: syntax error at or near ";"
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LINE 1: CREATE STATISTICS tst;
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^
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CREATE STATISTICS tst ON a, b;
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ERROR: syntax error at or near ";"
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LINE 1: CREATE STATISTICS tst ON a, b;
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^
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CREATE STATISTICS tst FROM sometab;
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ERROR: syntax error at or near "FROM"
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LINE 1: CREATE STATISTICS tst FROM sometab;
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^
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CREATE STATISTICS tst ON a, b FROM nonexistent;
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ERROR: relation "nonexistent" does not exist
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CREATE STATISTICS tst ON a, b FROM ext_stats_test;
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ERROR: column "a" does not exist
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CREATE STATISTICS tst ON x, x, y FROM ext_stats_test;
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ERROR: duplicate column name in statistics definition
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CREATE STATISTICS tst ON x, x, y, x, x, y, x, x, y FROM ext_stats_test;
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ERROR: cannot have more than 8 columns in statistics
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CREATE STATISTICS tst ON x, x, y, x, x, (x || 'x'), (y + 1), (x || 'x'), (x || 'x'), (y + 1) FROM ext_stats_test;
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ERROR: cannot have more than 8 columns in statistics
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CREATE STATISTICS tst ON (x || 'x'), (x || 'x'), (y + 1), (x || 'x'), (x || 'x'), (y + 1), (x || 'x'), (x || 'x'), (y + 1) FROM ext_stats_test;
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ERROR: cannot have more than 8 columns in statistics
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CREATE STATISTICS tst ON (x || 'x'), (x || 'x'), y FROM ext_stats_test;
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ERROR: duplicate expression in statistics definition
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CREATE STATISTICS tst (unrecognized) ON x, y FROM ext_stats_test;
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ERROR: unrecognized statistics kind "unrecognized"
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-- incorrect expressions
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CREATE STATISTICS tst ON (y) FROM ext_stats_test; -- single column reference
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ERROR: extended statistics require at least 2 columns
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CREATE STATISTICS tst ON y + z FROM ext_stats_test; -- missing parentheses
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ERROR: syntax error at or near "+"
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LINE 1: CREATE STATISTICS tst ON y + z FROM ext_stats_test;
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^
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CREATE STATISTICS tst ON (x, y) FROM ext_stats_test; -- tuple expression
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ERROR: syntax error at or near ","
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LINE 1: CREATE STATISTICS tst ON (x, y) FROM ext_stats_test;
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^
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DROP TABLE ext_stats_test;
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-- Ensure stats are dropped sanely, and test IF NOT EXISTS while at it
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CREATE TABLE ab1 (a INTEGER, b INTEGER, c INTEGER);
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CREATE STATISTICS IF NOT EXISTS ab1_a_b_stats ON a, b FROM ab1;
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COMMENT ON STATISTICS ab1_a_b_stats IS 'new comment';
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CREATE ROLE regress_stats_ext;
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SET SESSION AUTHORIZATION regress_stats_ext;
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COMMENT ON STATISTICS ab1_a_b_stats IS 'changed comment';
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ERROR: must be owner of statistics object ab1_a_b_stats
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DROP STATISTICS ab1_a_b_stats;
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ERROR: must be owner of statistics object ab1_a_b_stats
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ALTER STATISTICS ab1_a_b_stats RENAME TO ab1_a_b_stats_new;
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ERROR: must be owner of statistics object ab1_a_b_stats
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RESET SESSION AUTHORIZATION;
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DROP ROLE regress_stats_ext;
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CREATE STATISTICS IF NOT EXISTS ab1_a_b_stats ON a, b FROM ab1;
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NOTICE: statistics object "ab1_a_b_stats" already exists, skipping
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DROP STATISTICS ab1_a_b_stats;
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CREATE SCHEMA regress_schema_2;
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CREATE STATISTICS regress_schema_2.ab1_a_b_stats ON a, b FROM ab1;
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-- Let's also verify the pg_get_statisticsobjdef output looks sane.
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SELECT pg_get_statisticsobjdef(oid) FROM pg_statistic_ext WHERE stxname = 'ab1_a_b_stats';
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pg_get_statisticsobjdef
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-------------------------------------------------------------------
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CREATE STATISTICS regress_schema_2.ab1_a_b_stats ON a, b FROM ab1
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(1 row)
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DROP STATISTICS regress_schema_2.ab1_a_b_stats;
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-- Ensure statistics are dropped when columns are
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CREATE STATISTICS ab1_b_c_stats ON b, c FROM ab1;
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CREATE STATISTICS ab1_a_b_c_stats ON a, b, c FROM ab1;
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CREATE STATISTICS ab1_b_a_stats ON b, a FROM ab1;
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ALTER TABLE ab1 DROP COLUMN a;
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\d ab1
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Table "public.ab1"
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Column | Type | Collation | Nullable | Default
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--------+---------+-----------+----------+---------
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b | integer | | |
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c | integer | | |
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Statistics objects:
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"public.ab1_b_c_stats" ON b, c FROM ab1
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-- Ensure statistics are dropped when table is
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SELECT stxname FROM pg_statistic_ext WHERE stxname LIKE 'ab1%';
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stxname
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---------------
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ab1_b_c_stats
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(1 row)
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DROP TABLE ab1;
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SELECT stxname FROM pg_statistic_ext WHERE stxname LIKE 'ab1%';
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stxname
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---------
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(0 rows)
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-- Ensure things work sanely with SET STATISTICS 0
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CREATE TABLE ab1 (a INTEGER, b INTEGER);
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ALTER TABLE ab1 ALTER a SET STATISTICS 0;
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INSERT INTO ab1 SELECT a, a%23 FROM generate_series(1, 1000) a;
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CREATE STATISTICS ab1_a_b_stats ON a, b FROM ab1;
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ANALYZE ab1;
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WARNING: statistics object "public.ab1_a_b_stats" could not be computed for relation "public.ab1"
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ALTER TABLE ab1 ALTER a SET STATISTICS -1;
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-- setting statistics target 0 skips the statistics, without printing any message, so check catalog
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ALTER STATISTICS ab1_a_b_stats SET STATISTICS 0;
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\d ab1
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Table "public.ab1"
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Column | Type | Collation | Nullable | Default
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--------+---------+-----------+----------+---------
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a | integer | | |
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b | integer | | |
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Statistics objects:
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"public.ab1_a_b_stats" ON a, b FROM ab1; STATISTICS 0
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ANALYZE ab1;
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SELECT stxname, stxdndistinct, stxddependencies, stxdmcv, stxdinherit
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FROM pg_statistic_ext s LEFT JOIN pg_statistic_ext_data d ON (d.stxoid = s.oid)
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WHERE s.stxname = 'ab1_a_b_stats';
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stxname | stxdndistinct | stxddependencies | stxdmcv | stxdinherit
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---------------+---------------+------------------+---------+-------------
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ab1_a_b_stats | | | |
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(1 row)
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ALTER STATISTICS ab1_a_b_stats SET STATISTICS -1;
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\d+ ab1
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Table "public.ab1"
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Column | Type | Collation | Nullable | Default | Storage | Stats target | Description
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--------+---------+-----------+----------+---------+---------+--------------+-------------
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a | integer | | | | plain | |
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b | integer | | | | plain | |
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Statistics objects:
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"public.ab1_a_b_stats" ON a, b FROM ab1
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-- partial analyze doesn't build stats either
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ANALYZE ab1 (a);
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WARNING: statistics object "public.ab1_a_b_stats" could not be computed for relation "public.ab1"
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ANALYZE ab1;
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DROP TABLE ab1;
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ALTER STATISTICS ab1_a_b_stats SET STATISTICS 0;
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ERROR: statistics object "ab1_a_b_stats" does not exist
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ALTER STATISTICS IF EXISTS ab1_a_b_stats SET STATISTICS 0;
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NOTICE: statistics object "ab1_a_b_stats" does not exist, skipping
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-- Ensure we can build statistics for tables with inheritance.
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CREATE TABLE ab1 (a INTEGER, b INTEGER);
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CREATE TABLE ab1c () INHERITS (ab1);
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INSERT INTO ab1 VALUES (1,1);
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CREATE STATISTICS ab1_a_b_stats ON a, b FROM ab1;
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ANALYZE ab1;
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DROP TABLE ab1 CASCADE;
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NOTICE: drop cascades to table ab1c
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-- Tests for stats with inheritance
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CREATE TABLE stxdinh(a int, b int);
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CREATE TABLE stxdinh1() INHERITS(stxdinh);
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CREATE TABLE stxdinh2() INHERITS(stxdinh);
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INSERT INTO stxdinh SELECT mod(a,50), mod(a,100) FROM generate_series(0, 1999) a;
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INSERT INTO stxdinh1 SELECT mod(a,100), mod(a,100) FROM generate_series(0, 999) a;
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INSERT INTO stxdinh2 SELECT mod(a,100), mod(a,100) FROM generate_series(0, 999) a;
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VACUUM ANALYZE stxdinh, stxdinh1, stxdinh2;
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-- Ensure non-inherited stats are not applied to inherited query
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-- Without stats object, it looks like this
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SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* GROUP BY 1, 2');
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estimated | actual
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-----------+--------
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400 | 150
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* WHERE a = 0 AND b = 0');
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estimated | actual
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-----------+--------
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3 | 40
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(1 row)
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CREATE STATISTICS stxdinh ON a, b FROM stxdinh;
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VACUUM ANALYZE stxdinh, stxdinh1, stxdinh2;
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-- See if the extended stats affect the estimates
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SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* GROUP BY 1, 2');
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estimated | actual
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-----------+--------
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150 | 150
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(1 row)
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-- Dependencies are applied at individual relations (within append), so
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-- this estimate changes a bit because we improve estimates for the parent
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SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* WHERE a = 0 AND b = 0');
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estimated | actual
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-----------+--------
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22 | 40
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(1 row)
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-- Ensure correct (non-inherited) stats are applied to inherited query
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SELECT * FROM check_estimated_rows('SELECT a, b FROM ONLY stxdinh GROUP BY 1, 2');
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estimated | actual
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-----------+--------
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100 | 100
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT a, b FROM ONLY stxdinh WHERE a = 0 AND b = 0');
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estimated | actual
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-----------+--------
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20 | 20
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(1 row)
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DROP TABLE stxdinh, stxdinh1, stxdinh2;
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-- Ensure inherited stats ARE applied to inherited query in partitioned table
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CREATE TABLE stxdinp(i int, a int, b int) PARTITION BY RANGE (i);
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CREATE TABLE stxdinp1 PARTITION OF stxdinp FOR VALUES FROM (1) TO (100);
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INSERT INTO stxdinp SELECT 1, a/100, a/100 FROM generate_series(1, 999) a;
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CREATE STATISTICS stxdinp ON (a + 1), a, b FROM stxdinp;
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VACUUM ANALYZE stxdinp; -- partitions are processed recursively
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SELECT 1 FROM pg_statistic_ext WHERE stxrelid = 'stxdinp'::regclass;
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?column?
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----------
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1
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinp GROUP BY 1, 2');
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estimated | actual
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-----------+--------
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10 | 10
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT a + 1, b FROM ONLY stxdinp GROUP BY 1, 2');
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estimated | actual
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-----------+--------
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1 | 0
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(1 row)
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DROP TABLE stxdinp;
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-- basic test for statistics on expressions
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CREATE TABLE ab1 (a INTEGER, b INTEGER, c TIMESTAMP, d TIMESTAMPTZ);
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-- expression stats may be built on a single expression column
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CREATE STATISTICS ab1_exprstat_1 ON (a+b) FROM ab1;
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-- with a single expression, we only enable expression statistics
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CREATE STATISTICS ab1_exprstat_2 ON (a+b) FROM ab1;
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SELECT stxkind FROM pg_statistic_ext WHERE stxname = 'ab1_exprstat_2';
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stxkind
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---------
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{e}
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(1 row)
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-- adding anything to the expression builds all statistics kinds
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CREATE STATISTICS ab1_exprstat_3 ON (a+b), a FROM ab1;
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SELECT stxkind FROM pg_statistic_ext WHERE stxname = 'ab1_exprstat_3';
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stxkind
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-----------
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{d,f,m,e}
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(1 row)
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-- date_trunc on timestamptz is not immutable, but that should not matter
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CREATE STATISTICS ab1_exprstat_4 ON date_trunc('day', d) FROM ab1;
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-- date_trunc on timestamp is immutable
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CREATE STATISTICS ab1_exprstat_5 ON date_trunc('day', c) FROM ab1;
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-- check use of a boolean-returning expression
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CREATE STATISTICS ab1_exprstat_6 ON
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(case a when 1 then true else false end), b FROM ab1;
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-- insert some data and run analyze, to test that these cases build properly
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INSERT INTO ab1
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SELECT x / 10, x / 3,
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'2020-10-01'::timestamp + x * interval '1 day',
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'2020-10-01'::timestamptz + x * interval '1 day'
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FROM generate_series(1, 100) x;
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ANALYZE ab1;
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-- apply some stats
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SELECT * FROM check_estimated_rows('SELECT * FROM ab1 WHERE (case a when 1 then true else false end) AND b=2');
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estimated | actual
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-----------+--------
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1 | 0
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(1 row)
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DROP TABLE ab1;
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-- Verify supported object types for extended statistics
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CREATE schema tststats;
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CREATE TABLE tststats.t (a int, b int, c text);
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CREATE INDEX ti ON tststats.t (a, b);
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CREATE SEQUENCE tststats.s;
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CREATE VIEW tststats.v AS SELECT * FROM tststats.t;
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CREATE MATERIALIZED VIEW tststats.mv AS SELECT * FROM tststats.t;
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CREATE TYPE tststats.ty AS (a int, b int, c text);
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CREATE FOREIGN DATA WRAPPER extstats_dummy_fdw;
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CREATE SERVER extstats_dummy_srv FOREIGN DATA WRAPPER extstats_dummy_fdw;
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CREATE FOREIGN TABLE tststats.f (a int, b int, c text) SERVER extstats_dummy_srv;
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CREATE TABLE tststats.pt (a int, b int, c text) PARTITION BY RANGE (a, b);
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CREATE TABLE tststats.pt1 PARTITION OF tststats.pt FOR VALUES FROM (-10, -10) TO (10, 10);
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CREATE STATISTICS tststats.s1 ON a, b FROM tststats.t;
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CREATE STATISTICS tststats.s2 ON a, b FROM tststats.ti;
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ERROR: cannot define statistics for relation "ti"
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DETAIL: This operation is not supported for indexes.
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CREATE STATISTICS tststats.s3 ON a, b FROM tststats.s;
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ERROR: cannot define statistics for relation "s"
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DETAIL: This operation is not supported for sequences.
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CREATE STATISTICS tststats.s4 ON a, b FROM tststats.v;
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ERROR: cannot define statistics for relation "v"
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DETAIL: This operation is not supported for views.
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CREATE STATISTICS tststats.s5 ON a, b FROM tststats.mv;
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CREATE STATISTICS tststats.s6 ON a, b FROM tststats.ty;
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ERROR: cannot define statistics for relation "ty"
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DETAIL: This operation is not supported for composite types.
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CREATE STATISTICS tststats.s7 ON a, b FROM tststats.f;
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CREATE STATISTICS tststats.s8 ON a, b FROM tststats.pt;
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CREATE STATISTICS tststats.s9 ON a, b FROM tststats.pt1;
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DO $$
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DECLARE
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relname text := reltoastrelid::regclass FROM pg_class WHERE oid = 'tststats.t'::regclass;
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BEGIN
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EXECUTE 'CREATE STATISTICS tststats.s10 ON a, b FROM ' || relname;
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EXCEPTION WHEN wrong_object_type THEN
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RAISE NOTICE 'stats on toast table not created';
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END;
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$$;
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NOTICE: stats on toast table not created
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DROP SCHEMA tststats CASCADE;
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NOTICE: drop cascades to 7 other objects
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DETAIL: drop cascades to table tststats.t
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drop cascades to sequence tststats.s
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drop cascades to view tststats.v
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drop cascades to materialized view tststats.mv
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drop cascades to type tststats.ty
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drop cascades to foreign table tststats.f
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drop cascades to table tststats.pt
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DROP FOREIGN DATA WRAPPER extstats_dummy_fdw CASCADE;
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NOTICE: drop cascades to server extstats_dummy_srv
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-- n-distinct tests
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CREATE TABLE ndistinct (
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filler1 TEXT,
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filler2 NUMERIC,
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a INT,
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b INT,
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filler3 DATE,
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c INT,
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d INT
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)
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WITH (autovacuum_enabled = off);
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-- over-estimates when using only per-column statistics
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INSERT INTO ndistinct (a, b, c, filler1)
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SELECT i/100, i/100, i/100, cash_words((i/100)::money)
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FROM generate_series(1,1000) s(i);
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ANALYZE ndistinct;
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-- Group Aggregate, due to over-estimate of the number of groups
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
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estimated | actual
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-----------+--------
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200 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
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estimated | actual
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-----------+--------
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200 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (a+1)');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100)');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100), (2*c)');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (a+1), (b+100)');
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estimated | actual
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-----------+--------
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100 | 11
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(1 row)
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-- correct command
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CREATE STATISTICS s10 ON a, b, c FROM ndistinct;
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ANALYZE ndistinct;
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SELECT s.stxkind, d.stxdndistinct
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FROM pg_statistic_ext s, pg_statistic_ext_data d
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WHERE s.stxrelid = 'ndistinct'::regclass
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AND d.stxoid = s.oid;
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stxkind | stxdndistinct
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---------+-----------------------------------------------------
|
|
{d,f,m} | {"3, 4": 11, "3, 6": 11, "4, 6": 11, "3, 4, 6": 11}
|
|
(1 row)
|
|
|
|
-- minor improvement, make sure the ctid does not break the matching
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY ctid, a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
-- Hash Aggregate, thanks to estimates improved by the statistic
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
-- partial improvement (match on attributes)
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (a+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
-- expressions - no improvement
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100), (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 11
|
|
(1 row)
|
|
|
|
-- last two plans keep using Group Aggregate, because 'd' is not covered
|
|
-- by the statistic and while it's NULL-only we assume 200 values for it
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 11
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 11
|
|
(1 row)
|
|
|
|
TRUNCATE TABLE ndistinct;
|
|
-- under-estimates when using only per-column statistics
|
|
INSERT INTO ndistinct (a, b, c, filler1)
|
|
SELECT mod(i,13), mod(i,17), mod(i,19),
|
|
cash_words(mod(i,23)::int::money)
|
|
FROM generate_series(1,1000) s(i);
|
|
ANALYZE ndistinct;
|
|
SELECT s.stxkind, d.stxdndistinct
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d
|
|
WHERE s.stxrelid = 'ndistinct'::regclass
|
|
AND d.stxoid = s.oid;
|
|
stxkind | stxdndistinct
|
|
---------+----------------------------------------------------------
|
|
{d,f,m} | {"3, 4": 221, "3, 6": 247, "4, 6": 323, "3, 4, 6": 1000}
|
|
(1 row)
|
|
|
|
-- correct estimates
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
323 | 323
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 13
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (a+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100), (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
DROP STATISTICS s10;
|
|
SELECT s.stxkind, d.stxdndistinct
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d
|
|
WHERE s.stxrelid = 'ndistinct'::regclass
|
|
AND d.stxoid = s.oid;
|
|
stxkind | stxdndistinct
|
|
---------+---------------
|
|
(0 rows)
|
|
|
|
-- dropping the statistics results in under-estimates
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 323
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, d');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 13
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (a+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100), (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
-- ndistinct estimates with statistics on expressions
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100), (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
CREATE STATISTICS s10 (ndistinct) ON (a+1), (b+100), (2*c) FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT s.stxkind, d.stxdndistinct
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d
|
|
WHERE s.stxrelid = 'ndistinct'::regclass
|
|
AND d.stxoid = s.oid;
|
|
stxkind | stxdndistinct
|
|
---------+-------------------------------------------------------------------
|
|
{d,e} | {"-1, -2": 221, "-1, -3": 247, "-2, -3": 323, "-1, -2, -3": 1000}
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a+1), (b+100), (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (a+1), (b+100)');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
DROP STATISTICS s10;
|
|
-- a mix of attributes and expressions
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 247
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 1000
|
|
(1 row)
|
|
|
|
CREATE STATISTICS s10 (ndistinct) ON a, b, (2*c) FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT s.stxkind, d.stxdndistinct
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d
|
|
WHERE s.stxrelid = 'ndistinct'::regclass
|
|
AND d.stxoid = s.oid;
|
|
stxkind | stxdndistinct
|
|
---------+-------------------------------------------------------------
|
|
{d,e} | {"3, 4": 221, "3, -1": 247, "4, -1": 323, "3, 4, -1": 1000}
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
221 | 221
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
247 | 247
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (2*c)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
DROP STATISTICS s10;
|
|
-- combination of multiple ndistinct statistics, with/without expressions
|
|
TRUNCATE ndistinct;
|
|
-- two mostly independent groups of columns
|
|
INSERT INTO ndistinct (a, b, c, d)
|
|
SELECT mod(i,3), mod(i,9), mod(i,5), mod(i,20)
|
|
FROM generate_series(1,1000) s(i);
|
|
ANALYZE ndistinct;
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
27 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
27 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), b');
|
|
estimated | actual
|
|
-----------+--------
|
|
27 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
27 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1), c');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (c*10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1), c, (d - 1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 180
|
|
(1 row)
|
|
|
|
-- basic statistics on both attributes (no expressions)
|
|
CREATE STATISTICS s11 (ndistinct) ON a, b FROM ndistinct;
|
|
CREATE STATISTICS s12 (ndistinct) ON c, d FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1), c');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (c*10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1), c, (d - 1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 180
|
|
(1 row)
|
|
|
|
-- replace the second statistics by statistics on expressions
|
|
DROP STATISTICS s12;
|
|
CREATE STATISTICS s12 (ndistinct) ON (c * 10), (d - 1) FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1), c');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (c*10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1), c, (d - 1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 180
|
|
(1 row)
|
|
|
|
-- replace the second statistics by statistics on both attributes and expressions
|
|
DROP STATISTICS s12;
|
|
CREATE STATISTICS s12 (ndistinct) ON c, d, (c * 10), (d - 1) FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1), c');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (c*10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1), c, (d - 1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 180
|
|
(1 row)
|
|
|
|
-- replace the other statistics by statistics on both attributes and expressions
|
|
DROP STATISTICS s11;
|
|
CREATE STATISTICS s11 (ndistinct) ON a, b, (a*5), (b+1) FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1), c');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (c*10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1), c, (d - 1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 180
|
|
(1 row)
|
|
|
|
-- replace statistics by somewhat overlapping ones (this expected to get worse estimate
|
|
-- because the first statistics shall be applied to 3 columns, and the second one can't
|
|
-- be really applied)
|
|
DROP STATISTICS s11;
|
|
DROP STATISTICS s12;
|
|
CREATE STATISTICS s11 (ndistinct) ON a, b, (a*5), (b+1) FROM ndistinct;
|
|
CREATE STATISTICS s12 (ndistinct) ON a, (b+1), (c * 10) FROM ndistinct;
|
|
ANALYZE ndistinct;
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), b');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
9 | 9
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY (a*5), (b+1), c');
|
|
estimated | actual
|
|
-----------+--------
|
|
45 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, (c*10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 45
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, (b+1), c, (d - 1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 180
|
|
(1 row)
|
|
|
|
DROP STATISTICS s11;
|
|
DROP STATISTICS s12;
|
|
-- functional dependencies tests
|
|
CREATE TABLE functional_dependencies (
|
|
filler1 TEXT,
|
|
filler2 NUMERIC,
|
|
a INT,
|
|
b TEXT,
|
|
filler3 DATE,
|
|
c INT,
|
|
d TEXT
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
CREATE INDEX fdeps_ab_idx ON functional_dependencies (a, b);
|
|
CREATE INDEX fdeps_abc_idx ON functional_dependencies (a, b, c);
|
|
-- random data (no functional dependencies)
|
|
INSERT INTO functional_dependencies (a, b, c, filler1)
|
|
SELECT mod(i, 5), mod(i, 7), mod(i, 11), i FROM generate_series(1,1000) s(i);
|
|
ANALYZE functional_dependencies;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
29 | 29
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 3
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS func_deps_stat (dependencies) ON a, b, c FROM functional_dependencies;
|
|
ANALYZE functional_dependencies;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
29 | 29
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 3
|
|
(1 row)
|
|
|
|
-- a => b, a => c, b => c
|
|
TRUNCATE functional_dependencies;
|
|
DROP STATISTICS func_deps_stat;
|
|
-- now do the same thing, but with expressions
|
|
INSERT INTO functional_dependencies (a, b, c, filler1)
|
|
SELECT i, i, i, i FROM generate_series(1,5000) s(i);
|
|
ANALYZE functional_dependencies;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE mod(a, 11) = 1 AND mod(b::int, 13) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 35
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE mod(a, 11) = 1 AND mod(b::int, 13) = 1 AND mod(c, 7) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 5
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS func_deps_stat (dependencies) ON (mod(a,11)), (mod(b::int, 13)), (mod(c, 7)) FROM functional_dependencies;
|
|
ANALYZE functional_dependencies;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE mod(a, 11) = 1 AND mod(b::int, 13) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
35 | 35
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE mod(a, 11) = 1 AND mod(b::int, 13) = 1 AND mod(c, 7) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
5 | 5
|
|
(1 row)
|
|
|
|
-- a => b, a => c, b => c
|
|
TRUNCATE functional_dependencies;
|
|
DROP STATISTICS func_deps_stat;
|
|
INSERT INTO functional_dependencies (a, b, c, filler1)
|
|
SELECT mod(i,100), mod(i,50), mod(i,25), i FROM generate_series(1,5000) s(i);
|
|
ANALYZE functional_dependencies;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
-- IN
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c IN (1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 26, 27, 51, 52, 76, 77) AND b IN (''1'', ''2'', ''26'', ''27'') AND c IN (1, 2)');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 400
|
|
(1 row)
|
|
|
|
-- OR clauses referencing the same attribute
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND (b = ''1'' OR b = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 2 OR a = 51 OR a = 52) AND (b = ''1'' OR b = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
-- OR clauses referencing different attributes
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR b = ''1'') AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 100
|
|
(1 row)
|
|
|
|
-- ANY
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = ANY (ARRAY[1])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 26, 27, 51, 52, 76, 77]) AND b = ANY (ARRAY[''1'', ''2'', ''26'', ''27'']) AND c = ANY (ARRAY[1, 2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 400
|
|
(1 row)
|
|
|
|
-- ANY with inequalities should not benefit from functional dependencies
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a < ANY (ARRAY[1, 51]) AND b > ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2472 | 2400
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a >= ANY (ARRAY[1, 51]) AND b <= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1441 | 1250
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a <= ANY (ARRAY[1, 2, 51, 52]) AND b >= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
3909 | 2550
|
|
(1 row)
|
|
|
|
-- ALL (should not benefit from functional dependencies)
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS func_deps_stat (dependencies) ON a, b, c FROM functional_dependencies;
|
|
ANALYZE functional_dependencies;
|
|
-- print the detected dependencies
|
|
SELECT dependencies FROM pg_stats_ext WHERE statistics_name = 'func_deps_stat';
|
|
dependencies
|
|
------------------------------------------------------------------------------------------------------------
|
|
{"3 => 4": 1.000000, "3 => 6": 1.000000, "4 => 6": 1.000000, "3, 4 => 6": 1.000000, "3, 6 => 4": 1.000000}
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
-- IN
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c IN (1)');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 26, 27, 51, 52, 76, 77) AND b IN (''1'', ''2'', ''26'', ''27'') AND c IN (1, 2)');
|
|
estimated | actual
|
|
-----------+--------
|
|
400 | 400
|
|
(1 row)
|
|
|
|
-- OR clauses referencing the same attribute
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
99 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND (b = ''1'' OR b = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
99 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 2 OR a = 51 OR a = 52) AND (b = ''1'' OR b = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
197 | 200
|
|
(1 row)
|
|
|
|
-- OR clauses referencing different attributes are incompatible
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR b = ''1'') AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 100
|
|
(1 row)
|
|
|
|
-- ANY
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = ANY (ARRAY[1])');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 26, 27, 51, 52, 76, 77]) AND b = ANY (ARRAY[''1'', ''2'', ''26'', ''27'']) AND c = ANY (ARRAY[1, 2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
400 | 400
|
|
(1 row)
|
|
|
|
-- ANY with inequalities should not benefit from functional dependencies
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a < ANY (ARRAY[1, 51]) AND b > ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2472 | 2400
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a >= ANY (ARRAY[1, 51]) AND b <= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1441 | 1250
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a <= ANY (ARRAY[1, 2, 51, 52]) AND b >= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
3909 | 2550
|
|
(1 row)
|
|
|
|
-- ALL (should not benefit from functional dependencies)
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
-- changing the type of column c causes all its stats to be dropped, reverting
|
|
-- to default estimates without any statistics, i.e. 0.5% selectivity for each
|
|
-- condition
|
|
ALTER TABLE functional_dependencies ALTER COLUMN c TYPE numeric;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
ANALYZE functional_dependencies;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
DROP STATISTICS func_deps_stat;
|
|
-- now try functional dependencies with expressions
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = 2 AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = 2 AND upper(b) = ''1'' AND (c + 1) = 2');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
-- IN
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 102, 104) AND upper(b) IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 102, 104) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 52, 102, 152) AND upper(b) IN (''1'', ''26'') AND (c + 1) = 2');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 52, 102, 152) AND upper(b) IN (''1'', ''26'') AND (c + 1) IN (2)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 52, 54, 102, 104, 152, 154) AND upper(b) IN (''1'', ''2'', ''26'', ''27'') AND (c + 1) IN (2, 3)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 400
|
|
(1 row)
|
|
|
|
-- OR clauses referencing the same attribute
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 102) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 102) AND (upper(b) = ''1'' OR upper(b) = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 4 OR (a * 2) = 102 OR (a * 2) = 104) AND (upper(b) = ''1'' OR upper(b) = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
-- OR clauses referencing different attributes
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR upper(b) = ''1'') AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
-- ANY
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 102]) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 102]) AND upper(b) = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 4, 102, 104]) AND upper(b) = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 52, 102, 152]) AND upper(b) = ANY (ARRAY[''1'', ''26'']) AND (c + 1) = 2');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 52, 102, 152]) AND upper(b) = ANY (ARRAY[''1'', ''26'']) AND (c + 1) = ANY (ARRAY[2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 4, 52, 54, 102, 104, 152, 154]) AND upper(b) = ANY (ARRAY[''1'', ''2'', ''26'', ''27'']) AND (c + 1) = ANY (ARRAY[2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 400
|
|
(1 row)
|
|
|
|
-- ANY with inequalities should not benefit from functional dependencies
|
|
-- the estimates however improve thanks to having expression statistics
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) < ANY (ARRAY[2, 102]) AND upper(b) > ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
926 | 2400
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) >= ANY (ARRAY[2, 102]) AND upper(b) <= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1543 | 1250
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) <= ANY (ARRAY[2, 4, 102, 104]) AND upper(b) >= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
2229 | 2550
|
|
(1 row)
|
|
|
|
-- ALL (should not benefit from functional dependencies)
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) = ALL (ARRAY[''1''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 102, 104) AND upper(b) = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
-- create statistics on expressions
|
|
CREATE STATISTICS func_deps_stat (dependencies) ON (a * 2), upper(b), (c + 1) FROM functional_dependencies;
|
|
ANALYZE functional_dependencies;
|
|
-- print the detected dependencies
|
|
SELECT dependencies FROM pg_stats_ext WHERE statistics_name = 'func_deps_stat';
|
|
dependencies
|
|
------------------------------------------------------------------------------------------------------------------------
|
|
{"-1 => -2": 1.000000, "-1 => -3": 1.000000, "-2 => -3": 1.000000, "-1, -2 => -3": 1.000000, "-1, -3 => -2": 1.000000}
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = 2 AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = 2 AND upper(b) = ''1'' AND (c + 1) = 2');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
-- IN
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 102, 104) AND upper(b) IN (''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 102, 104) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 52, 102, 152) AND upper(b) IN (''1'', ''26'') AND (c + 1) = 2');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 52, 102, 152) AND upper(b) IN (''1'', ''26'') AND (c + 1) IN (2)');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 52, 54, 102, 104, 152, 154) AND upper(b) IN (''1'', ''2'', ''26'', ''27'') AND (c + 1) IN (2, 3)');
|
|
estimated | actual
|
|
-----------+--------
|
|
400 | 400
|
|
(1 row)
|
|
|
|
-- OR clauses referencing the same attribute
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 102) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
99 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 102) AND (upper(b) = ''1'' OR upper(b) = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
99 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR (a * 2) = 4 OR (a * 2) = 102 OR (a * 2) = 104) AND (upper(b) = ''1'' OR upper(b) = ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
197 | 200
|
|
(1 row)
|
|
|
|
-- OR clauses referencing different attributes
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE ((a * 2) = 2 OR upper(b) = ''1'') AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 100
|
|
(1 row)
|
|
|
|
-- ANY
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 102]) AND upper(b) = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 102]) AND upper(b) = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 4, 102, 104]) AND upper(b) = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 52, 102, 152]) AND upper(b) = ANY (ARRAY[''1'', ''26'']) AND (c + 1) = 2');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 52, 102, 152]) AND upper(b) = ANY (ARRAY[''1'', ''26'']) AND (c + 1) = ANY (ARRAY[2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) = ANY (ARRAY[2, 4, 52, 54, 102, 104, 152, 154]) AND upper(b) = ANY (ARRAY[''1'', ''2'', ''26'', ''27'']) AND (c + 1) = ANY (ARRAY[2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
400 | 400
|
|
(1 row)
|
|
|
|
-- ANY with inequalities should not benefit from functional dependencies
|
|
-- the estimates however improve thanks to having expression statistics
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) < ANY (ARRAY[2, 102]) AND upper(b) > ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2472 | 2400
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) >= ANY (ARRAY[2, 102]) AND upper(b) <= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1441 | 1250
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) <= ANY (ARRAY[2, 4, 102, 104]) AND upper(b) >= ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
3909 | 2550
|
|
(1 row)
|
|
|
|
-- ALL (should not benefit from functional dependencies)
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) = ALL (ARRAY[''1''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 102) AND upper(b) = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a * 2) IN (2, 4, 102, 104) AND upper(b) = ALL (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
-- check the ability to use multiple functional dependencies
|
|
CREATE TABLE functional_dependencies_multi (
|
|
a INTEGER,
|
|
b INTEGER,
|
|
c INTEGER,
|
|
d INTEGER
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
INSERT INTO functional_dependencies_multi (a, b, c, d)
|
|
SELECT
|
|
mod(i,7),
|
|
mod(i,7),
|
|
mod(i,11),
|
|
mod(i,11)
|
|
FROM generate_series(1,5000) s(i);
|
|
ANALYZE functional_dependencies_multi;
|
|
-- estimates without any functional dependencies
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
102 | 714
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
|
|
estimated | actual
|
|
-----------+--------
|
|
102 | 714
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
41 | 454
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 64
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 64
|
|
(1 row)
|
|
|
|
-- create separate functional dependencies
|
|
CREATE STATISTICS functional_dependencies_multi_1 (dependencies) ON a, b FROM functional_dependencies_multi;
|
|
CREATE STATISTICS functional_dependencies_multi_2 (dependencies) ON c, d FROM functional_dependencies_multi;
|
|
ANALYZE functional_dependencies_multi;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
714 | 714
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
|
|
estimated | actual
|
|
-----------+--------
|
|
714 | 714
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
454 | 454
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
65 | 64
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
65 | 64
|
|
(1 row)
|
|
|
|
DROP TABLE functional_dependencies_multi;
|
|
-- MCV lists
|
|
CREATE TABLE mcv_lists (
|
|
filler1 TEXT,
|
|
filler2 NUMERIC,
|
|
a INT,
|
|
b VARCHAR,
|
|
filler3 DATE,
|
|
c INT,
|
|
d TEXT,
|
|
ia INT[]
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
-- random data (no MCV list)
|
|
INSERT INTO mcv_lists (a, b, c, filler1)
|
|
SELECT mod(i,37), mod(i,41), mod(i,43), mod(i,47) FROM generate_series(1,5000) s(i);
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 4
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 1
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3 | 4
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 1
|
|
(1 row)
|
|
|
|
TRUNCATE mcv_lists;
|
|
DROP STATISTICS mcv_lists_stats;
|
|
-- random data (no MCV list), but with expression
|
|
INSERT INTO mcv_lists (a, b, c, filler1)
|
|
SELECT i, i, i, i FROM generate_series(1,1000) s(i);
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,7) = 1 AND mod(b::int,11) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 13
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,7) = 1 AND mod(b::int,11) = 1 AND mod(c,13) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 1
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS mcv_lists_stats (mcv) ON (mod(a,7)), (mod(b::int,11)), (mod(c,13)) FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,7) = 1 AND mod(b::int,11) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
13 | 13
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,7) = 1 AND mod(b::int,11) = 1 AND mod(c,13) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 1
|
|
(1 row)
|
|
|
|
-- 100 distinct combinations, all in the MCV list
|
|
TRUNCATE mcv_lists;
|
|
DROP STATISTICS mcv_lists_stats;
|
|
INSERT INTO mcv_lists (a, b, c, ia, filler1)
|
|
SELECT mod(i,100), mod(i,50), mod(i,25), array[mod(i,25)], i
|
|
FROM generate_series(1,5000) s(i);
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = a AND ''1'' = b');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 1 AND b < ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > a AND ''1'' > b');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 0 AND b <= ''0''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 0 >= a AND ''0'' >= b');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND b < ''1'' AND c < 5');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND ''1'' > b AND 5 > c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <= ''0'' AND c <= 4');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 4 >= a AND ''0'' >= b AND 4 >= c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
343 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
343 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52) AND b IN ( ''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52, NULL) AND b IN ( ''1'', ''2'', NULL)');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[NULL, 1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2'', NULL])');
|
|
estimated | actual
|
|
-----------+--------
|
|
8 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, 2, 3]) AND b IN (''1'', ''2'', ''3'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
26 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, NULL, 2, 3]) AND b IN (''1'', ''2'', NULL, ''3'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
26 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
10 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3, NULL])');
|
|
estimated | actual
|
|
-----------+--------
|
|
10 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', ''3'') AND c > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', NULL, ''3'') AND c > ANY (ARRAY[1, 2, NULL, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[4,5]) AND 4 = ANY(ia)');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 50
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c, ia FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = a AND ''1'' = b');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 1 AND b < ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > a AND ''1'' > b');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 0 AND b <= ''0''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 0 >= a AND ''0'' >= b');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND b < ''1'' AND c < 5');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND ''1'' > b AND 5 > c');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <= ''0'' AND c <= 4');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 4 >= a AND ''0'' >= b AND 4 >= c');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52) AND b IN ( ''1'', ''2'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52, NULL) AND b IN ( ''1'', ''2'', NULL)');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[NULL, 1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2'', NULL])');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, 2, 3]) AND b IN (''1'', ''2'', ''3'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
150 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, NULL, 2, 3]) AND b IN (''1'', ''2'', NULL, ''3'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
150 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3, NULL])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', ''3'') AND c > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', NULL, ''3'') AND c > ANY (ARRAY[1, 2, NULL, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[4,5]) AND 4 = ANY(ia)');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 50
|
|
(1 row)
|
|
|
|
-- check change of unrelated column type does not reset the MCV statistics
|
|
ALTER TABLE mcv_lists ALTER COLUMN d TYPE VARCHAR(64);
|
|
SELECT d.stxdmcv IS NOT NULL
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d
|
|
WHERE s.stxname = 'mcv_lists_stats'
|
|
AND d.stxoid = s.oid;
|
|
?column?
|
|
----------
|
|
t
|
|
(1 row)
|
|
|
|
-- check change of column type resets the MCV statistics
|
|
ALTER TABLE mcv_lists ALTER COLUMN c TYPE numeric;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
-- 100 distinct combinations, all in the MCV list, but with expressions
|
|
TRUNCATE mcv_lists;
|
|
DROP STATISTICS mcv_lists_stats;
|
|
INSERT INTO mcv_lists (a, b, c, filler1)
|
|
SELECT i, i, i, i FROM generate_series(1,1000) s(i);
|
|
ANALYZE mcv_lists;
|
|
-- without any stats on the expressions, we have to use default selectivities, which
|
|
-- is why the estimates here are different from the pre-computed case above
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 AND mod(b::int,10) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = mod(a,20) AND 1 = mod(b::int,10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) < 1 AND mod(b::int,10) < 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
111 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > mod(a,20) AND 1 > mod(b::int,10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
111 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 AND mod(b::int,10) = 1 AND mod(c,5) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 OR mod(b::int,10) = 1 OR mod(c,25) = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
15 | 120
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) IN (1, 2, 51, 52, NULL) AND mod(b::int,10) IN ( 1, 2, NULL)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = ANY (ARRAY[1, 2, 51, 52]) AND mod(b::int,10) = ANY (ARRAY[1, 2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) <= ANY (ARRAY[1, NULL, 2, 3]) AND mod(b::int,10) IN (1, 2, NULL, 3)');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) < ALL (ARRAY[4, 5]) AND mod(b::int,10) IN (1, 2, 3) AND mod(c,5) > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
-- create statistics with expressions only (we create three separate stats, in order not to build more complex extended stats)
|
|
CREATE STATISTICS mcv_lists_stats_1 ON (mod(a,20)) FROM mcv_lists;
|
|
CREATE STATISTICS mcv_lists_stats_2 ON (mod(b::int,10)) FROM mcv_lists;
|
|
CREATE STATISTICS mcv_lists_stats_3 ON (mod(c,5)) FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 AND mod(b::int,10) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
5 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = mod(a,20) AND 1 = mod(b::int,10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
5 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) < 1 AND mod(b::int,10) < 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
5 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > mod(a,20) AND 1 > mod(b::int,10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
5 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 AND mod(b::int,10) = 1 AND mod(c,5) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 OR mod(b::int,10) = 1 OR mod(c,25) = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
149 | 120
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) IN (1, 2, 51, 52, NULL) AND mod(b::int,10) IN ( 1, 2, NULL)');
|
|
estimated | actual
|
|
-----------+--------
|
|
20 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = ANY (ARRAY[1, 2, 51, 52]) AND mod(b::int,10) = ANY (ARRAY[1, 2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
20 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) <= ANY (ARRAY[1, NULL, 2, 3]) AND mod(b::int,10) IN (1, 2, NULL, 3)');
|
|
estimated | actual
|
|
-----------+--------
|
|
116 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) < ALL (ARRAY[4, 5]) AND mod(b::int,10) IN (1, 2, 3) AND mod(c,5) > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
12 | 100
|
|
(1 row)
|
|
|
|
DROP STATISTICS mcv_lists_stats_1;
|
|
DROP STATISTICS mcv_lists_stats_2;
|
|
DROP STATISTICS mcv_lists_stats_3;
|
|
-- create statistics with both MCV and expressions
|
|
CREATE STATISTICS mcv_lists_stats (mcv) ON (mod(a,20)), (mod(b::int,10)), (mod(c,5)) FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 AND mod(b::int,10) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = mod(a,20) AND 1 = mod(b::int,10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) < 1 AND mod(b::int,10) < 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > mod(a,20) AND 1 > mod(b::int,10)');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 AND mod(b::int,10) = 1 AND mod(c,5) = 1');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 OR mod(b::int,10) = 1 OR mod(c,25) = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
105 | 120
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) IN (1, 2, 51, 52, NULL) AND mod(b::int,10) IN ( 1, 2, NULL)');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = ANY (ARRAY[1, 2, 51, 52]) AND mod(b::int,10) = ANY (ARRAY[1, 2])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) <= ANY (ARRAY[1, NULL, 2, 3]) AND mod(b::int,10) IN (1, 2, NULL, 3)');
|
|
estimated | actual
|
|
-----------+--------
|
|
150 | 150
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) < ALL (ARRAY[4, 5]) AND mod(b::int,10) IN (1, 2, 3) AND mod(c,5) > ANY (ARRAY[1, 2, 3])');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
-- we can't use the statistic for OR clauses that are not fully covered (missing 'd' attribute)
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE mod(a,20) = 1 OR mod(b::int,10) = 1 OR mod(c,5) = 1 OR d IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 200
|
|
(1 row)
|
|
|
|
-- 100 distinct combinations with NULL values, all in the MCV list
|
|
TRUNCATE mcv_lists;
|
|
DROP STATISTICS mcv_lists_stats;
|
|
INSERT INTO mcv_lists (a, b, c, filler1)
|
|
SELECT
|
|
(CASE WHEN mod(i,100) = 1 THEN NULL ELSE mod(i,100) END),
|
|
(CASE WHEN mod(i,50) = 1 THEN NULL ELSE mod(i,50) END),
|
|
(CASE WHEN mod(i,25) = 1 THEN NULL ELSE mod(i,25) END),
|
|
i
|
|
FROM generate_series(1,5000) s(i);
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL AND c IS NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
49 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NOT NULL AND b IS NULL AND c IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
95 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (0, 1) AND b IN (''0'', ''1'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL AND c IS NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NOT NULL AND b IS NULL AND c IS NOT NULL');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (0, 1) AND b IN (''0'', ''1'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
-- test pg_mcv_list_items with a very simple (single item) MCV list
|
|
TRUNCATE mcv_lists;
|
|
INSERT INTO mcv_lists (a, b, c) SELECT 1, 2, 3 FROM generate_series(1,1000) s(i);
|
|
ANALYZE mcv_lists;
|
|
SELECT m.*
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d,
|
|
pg_mcv_list_items(d.stxdmcv) m
|
|
WHERE s.stxname = 'mcv_lists_stats'
|
|
AND d.stxoid = s.oid;
|
|
index | values | nulls | frequency | base_frequency
|
|
-------+---------+---------+-----------+----------------
|
|
0 | {1,2,3} | {f,f,f} | 1 | 1
|
|
(1 row)
|
|
|
|
-- 2 distinct combinations with NULL values, all in the MCV list
|
|
TRUNCATE mcv_lists;
|
|
DROP STATISTICS mcv_lists_stats;
|
|
INSERT INTO mcv_lists (a, b, c, d)
|
|
SELECT
|
|
NULL, -- always NULL
|
|
(CASE WHEN mod(i,2) = 0 THEN NULL ELSE 'x' END),
|
|
(CASE WHEN mod(i,2) = 0 THEN NULL ELSE 0 END),
|
|
(CASE WHEN mod(i,2) = 0 THEN NULL ELSE 'x' END)
|
|
FROM generate_series(1,5000) s(i);
|
|
ANALYZE mcv_lists;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE b = ''x'' OR d = ''x''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3750 | 2500
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''x'' OR d = ''x''');
|
|
estimated | actual
|
|
-----------+--------
|
|
3750 | 2500
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND (b = ''x'' OR d = ''x'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
3750 | 2500
|
|
(1 row)
|
|
|
|
-- create statistics
|
|
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, d FROM mcv_lists;
|
|
ANALYZE mcv_lists;
|
|
-- test pg_mcv_list_items with MCV list containing variable-length data and NULLs
|
|
SELECT m.*
|
|
FROM pg_statistic_ext s, pg_statistic_ext_data d,
|
|
pg_mcv_list_items(d.stxdmcv) m
|
|
WHERE s.stxname = 'mcv_lists_stats'
|
|
AND d.stxoid = s.oid;
|
|
index | values | nulls | frequency | base_frequency
|
|
-------+------------------+---------+-----------+----------------
|
|
0 | {NULL,x,x} | {t,f,f} | 0.5 | 0.25
|
|
1 | {NULL,NULL,NULL} | {t,t,t} | 0.5 | 0.25
|
|
(2 rows)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE b = ''x'' OR d = ''x''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2500 | 2500
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''x'' OR d = ''x''');
|
|
estimated | actual
|
|
-----------+--------
|
|
2500 | 2500
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND (b = ''x'' OR d = ''x'')');
|
|
estimated | actual
|
|
-----------+--------
|
|
2500 | 2500
|
|
(1 row)
|
|
|
|
-- mcv with pass-by-ref fixlen types, e.g. uuid
|
|
CREATE TABLE mcv_lists_uuid (
|
|
a UUID,
|
|
b UUID,
|
|
c UUID
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
INSERT INTO mcv_lists_uuid (a, b, c)
|
|
SELECT
|
|
fipshash(mod(i,100)::text)::uuid,
|
|
fipshash(mod(i,50)::text)::uuid,
|
|
fipshash(mod(i,25)::text)::uuid
|
|
FROM generate_series(1,5000) s(i);
|
|
ANALYZE mcv_lists_uuid;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''e7f6c011-776e-8db7-cd33-0b54174fd76f'' AND b = ''e7f6c011-776e-8db7-cd33-0b54174fd76f''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''e7f6c011-776e-8db7-cd33-0b54174fd76f'' AND b = ''e7f6c011-776e-8db7-cd33-0b54174fd76f'' AND c = ''e7f6c011-776e-8db7-cd33-0b54174fd76f''');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 50
|
|
(1 row)
|
|
|
|
CREATE STATISTICS mcv_lists_uuid_stats (mcv) ON a, b, c
|
|
FROM mcv_lists_uuid;
|
|
ANALYZE mcv_lists_uuid;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''e7f6c011-776e-8db7-cd33-0b54174fd76f'' AND b = ''e7f6c011-776e-8db7-cd33-0b54174fd76f''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''e7f6c011-776e-8db7-cd33-0b54174fd76f'' AND b = ''e7f6c011-776e-8db7-cd33-0b54174fd76f'' AND c = ''e7f6c011-776e-8db7-cd33-0b54174fd76f''');
|
|
estimated | actual
|
|
-----------+--------
|
|
50 | 50
|
|
(1 row)
|
|
|
|
DROP TABLE mcv_lists_uuid;
|
|
-- mcv with arrays
|
|
CREATE TABLE mcv_lists_arrays (
|
|
a TEXT[],
|
|
b NUMERIC[],
|
|
c INT[]
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
INSERT INTO mcv_lists_arrays (a, b, c)
|
|
SELECT
|
|
ARRAY[fipshash((i/100)::text), fipshash((i/100-1)::text), fipshash((i/100+1)::text)],
|
|
ARRAY[(i/100-1)::numeric/1000, (i/100)::numeric/1000, (i/100+1)::numeric/1000],
|
|
ARRAY[(i/100-1), i/100, (i/100+1)]
|
|
FROM generate_series(1,5000) s(i);
|
|
CREATE STATISTICS mcv_lists_arrays_stats (mcv) ON a, b, c
|
|
FROM mcv_lists_arrays;
|
|
ANALYZE mcv_lists_arrays;
|
|
-- mcv with bool
|
|
CREATE TABLE mcv_lists_bool (
|
|
a BOOL,
|
|
b BOOL,
|
|
c BOOL
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
INSERT INTO mcv_lists_bool (a, b, c)
|
|
SELECT
|
|
(mod(i,2) = 0), (mod(i,4) = 0), (mod(i,8) = 0)
|
|
FROM generate_series(1,10000) s(i);
|
|
ANALYZE mcv_lists_bool;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE a AND b AND c');
|
|
estimated | actual
|
|
-----------+--------
|
|
156 | 1250
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND c');
|
|
estimated | actual
|
|
-----------+--------
|
|
156 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND NOT b AND c');
|
|
estimated | actual
|
|
-----------+--------
|
|
469 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND NOT c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1094 | 0
|
|
(1 row)
|
|
|
|
CREATE STATISTICS mcv_lists_bool_stats (mcv) ON a, b, c
|
|
FROM mcv_lists_bool;
|
|
ANALYZE mcv_lists_bool;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE a AND b AND c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1250 | 1250
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND NOT b AND c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND NOT c');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
-- mcv covering just a small fraction of data
|
|
CREATE TABLE mcv_lists_partial (
|
|
a INT,
|
|
b INT,
|
|
c INT
|
|
);
|
|
-- 10 frequent groups, each with 100 elements
|
|
INSERT INTO mcv_lists_partial (a, b, c)
|
|
SELECT
|
|
mod(i,10),
|
|
mod(i,10),
|
|
mod(i,10)
|
|
FROM generate_series(0,999) s(i);
|
|
-- 100 groups that will make it to the MCV list (includes the 10 frequent ones)
|
|
INSERT INTO mcv_lists_partial (a, b, c)
|
|
SELECT
|
|
i,
|
|
i,
|
|
i
|
|
FROM generate_series(0,99) s(i);
|
|
-- 4000 groups in total, most of which won't make it (just a single item)
|
|
INSERT INTO mcv_lists_partial (a, b, c)
|
|
SELECT
|
|
i,
|
|
i,
|
|
i
|
|
FROM generate_series(0,3999) s(i);
|
|
ANALYZE mcv_lists_partial;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 102
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
300 | 102
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 AND b = 10 AND c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 2
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 OR b = 10 OR c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
6 | 2
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
204 | 104
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0 AND c = 0) OR (a = 1 AND b = 1 AND c = 1) OR (a = 2 AND b = 2 AND c = 2)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 306
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0) OR (a = 0 AND c = 0) OR (b = 0 AND c = 0)');
|
|
estimated | actual
|
|
-----------+--------
|
|
6 | 102
|
|
(1 row)
|
|
|
|
CREATE STATISTICS mcv_lists_partial_stats (mcv) ON a, b, c
|
|
FROM mcv_lists_partial;
|
|
ANALYZE mcv_lists_partial;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
102 | 102
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
96 | 102
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 AND b = 10 AND c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 2
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 OR b = 10 OR c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
2 | 2
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 10');
|
|
estimated | actual
|
|
-----------+--------
|
|
102 | 104
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0 AND c = 0) OR (a = 1 AND b = 1 AND c = 1) OR (a = 2 AND b = 2 AND c = 2)');
|
|
estimated | actual
|
|
-----------+--------
|
|
306 | 306
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0) OR (a = 0 AND c = 0) OR (b = 0 AND c = 0)');
|
|
estimated | actual
|
|
-----------+--------
|
|
108 | 102
|
|
(1 row)
|
|
|
|
DROP TABLE mcv_lists_partial;
|
|
-- check the ability to use multiple MCV lists
|
|
CREATE TABLE mcv_lists_multi (
|
|
a INTEGER,
|
|
b INTEGER,
|
|
c INTEGER,
|
|
d INTEGER
|
|
)
|
|
WITH (autovacuum_enabled = off);
|
|
INSERT INTO mcv_lists_multi (a, b, c, d)
|
|
SELECT
|
|
mod(i,5),
|
|
mod(i,5),
|
|
mod(i,7),
|
|
mod(i,7)
|
|
FROM generate_series(1,5000) s(i);
|
|
ANALYZE mcv_lists_multi;
|
|
-- estimates without any mcv statistics
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
200 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
102 | 714
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 AND c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
143 | 142
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 OR c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1571 | 1572
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
4 | 142
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE (a = 0 AND b = 0) OR (c = 0 AND d = 0)');
|
|
estimated | actual
|
|
-----------+--------
|
|
298 | 1572
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 OR b = 0 OR c = 0 OR d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
2649 | 1572
|
|
(1 row)
|
|
|
|
-- create separate MCV statistics
|
|
CREATE STATISTICS mcv_lists_multi_1 (mcv) ON a, b FROM mcv_lists_multi;
|
|
CREATE STATISTICS mcv_lists_multi_2 (mcv) ON c, d FROM mcv_lists_multi;
|
|
ANALYZE mcv_lists_multi;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1000 | 1000
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
714 | 714
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 AND c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
143 | 142
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 OR c = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1571 | 1572
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
143 | 142
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE (a = 0 AND b = 0) OR (c = 0 AND d = 0)');
|
|
estimated | actual
|
|
-----------+--------
|
|
1571 | 1572
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 OR b = 0 OR c = 0 OR d = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1571 | 1572
|
|
(1 row)
|
|
|
|
DROP TABLE mcv_lists_multi;
|
|
-- statistics on integer expressions
|
|
CREATE TABLE expr_stats (a int, b int, c int);
|
|
INSERT INTO expr_stats SELECT mod(i,10), mod(i,10), mod(i,10) FROM generate_series(1,1000) s(i);
|
|
ANALYZE expr_stats;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE (2*a) = 0 AND (3*b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE (a+b) = 0 AND (a-b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
CREATE STATISTICS expr_stats_1 (mcv) ON (a+b), (a-b), (2*a), (3*b) FROM expr_stats;
|
|
ANALYZE expr_stats;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE (2*a) = 0 AND (3*b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE (a+b) = 0 AND (a-b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
DROP STATISTICS expr_stats_1;
|
|
DROP TABLE expr_stats;
|
|
-- statistics on a mix columns and expressions
|
|
CREATE TABLE expr_stats (a int, b int, c int);
|
|
INSERT INTO expr_stats SELECT mod(i,10), mod(i,10), mod(i,10) FROM generate_series(1,1000) s(i);
|
|
ANALYZE expr_stats;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 0 AND (2*a) = 0 AND (3*b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 3 AND b = 3 AND (a-b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 0 AND b = 1 AND (a-b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
CREATE STATISTICS expr_stats_1 (mcv) ON a, b, (2*a), (3*b), (a+b), (a-b) FROM expr_stats;
|
|
ANALYZE expr_stats;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 0 AND (2*a) = 0 AND (3*b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 3 AND b = 3 AND (a-b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 0 AND b = 1 AND (a-b) = 0');
|
|
estimated | actual
|
|
-----------+--------
|
|
1 | 0
|
|
(1 row)
|
|
|
|
DROP TABLE expr_stats;
|
|
-- statistics on expressions with different data types
|
|
CREATE TABLE expr_stats (a int, b name, c text);
|
|
INSERT INTO expr_stats SELECT mod(i,10), fipshash(mod(i,10)::text), fipshash(mod(i,10)::text) FROM generate_series(1,1000) s(i);
|
|
ANALYZE expr_stats;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 0 AND (b || c) <= ''z'' AND (c || b) >= ''0''');
|
|
estimated | actual
|
|
-----------+--------
|
|
11 | 100
|
|
(1 row)
|
|
|
|
CREATE STATISTICS expr_stats_1 (mcv) ON a, b, (b || c), (c || b) FROM expr_stats;
|
|
ANALYZE expr_stats;
|
|
SELECT * FROM check_estimated_rows('SELECT * FROM expr_stats WHERE a = 0 AND (b || c) <= ''z'' AND (c || b) >= ''0''');
|
|
estimated | actual
|
|
-----------+--------
|
|
100 | 100
|
|
(1 row)
|
|
|
|
DROP TABLE expr_stats;
|
|
-- test handling of a mix of compatible and incompatible expressions
|
|
CREATE TABLE expr_stats_incompatible_test (
|
|
c0 double precision,
|
|
c1 boolean NOT NULL
|
|
);
|
|
CREATE STATISTICS expr_stat_comp_1 ON c0, c1 FROM expr_stats_incompatible_test;
|
|
INSERT INTO expr_stats_incompatible_test VALUES (1234,false), (5678,true);
|
|
ANALYZE expr_stats_incompatible_test;
|
|
SELECT c0 FROM ONLY expr_stats_incompatible_test WHERE
|
|
(
|
|
upper('x') LIKE ('x'||('[0,1]'::int4range))
|
|
AND
|
|
(c0 IN (0, 1) OR c1)
|
|
);
|
|
c0
|
|
----
|
|
(0 rows)
|
|
|
|
DROP TABLE expr_stats_incompatible_test;
|
|
-- Permission tests. Users should not be able to see specific data values in
|
|
-- the extended statistics, if they lack permission to see those values in
|
|
-- the underlying table.
|
|
--
|
|
-- Currently this is only relevant for MCV stats.
|
|
CREATE SCHEMA tststats;
|
|
CREATE TABLE tststats.priv_test_tbl (
|
|
a int,
|
|
b int
|
|
);
|
|
INSERT INTO tststats.priv_test_tbl
|
|
SELECT mod(i,5), mod(i,10) FROM generate_series(1,100) s(i);
|
|
CREATE STATISTICS tststats.priv_test_stats (mcv) ON a, b
|
|
FROM tststats.priv_test_tbl;
|
|
ANALYZE tststats.priv_test_tbl;
|
|
-- Check printing info about extended statistics by \dX
|
|
create table stts_t1 (a int, b int);
|
|
create statistics (ndistinct) on a, b from stts_t1;
|
|
create statistics (ndistinct, dependencies) on a, b from stts_t1;
|
|
create statistics (ndistinct, dependencies, mcv) on a, b from stts_t1;
|
|
create table stts_t2 (a int, b int, c int);
|
|
create statistics on b, c from stts_t2;
|
|
create table stts_t3 (col1 int, col2 int, col3 int);
|
|
create statistics stts_hoge on col1, col2, col3 from stts_t3;
|
|
create schema stts_s1;
|
|
create schema stts_s2;
|
|
create statistics stts_s1.stts_foo on col1, col2 from stts_t3;
|
|
create statistics stts_s2.stts_yama (dependencies, mcv) on col1, col3 from stts_t3;
|
|
insert into stts_t1 select i,i from generate_series(1,100) i;
|
|
analyze stts_t1;
|
|
set search_path to public, stts_s1, stts_s2, tststats;
|
|
\dX
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
----------+------------------------+------------------------------------------------------------------+-----------+--------------+---------
|
|
public | func_deps_stat | (a * 2), upper(b), (c + 1::numeric) FROM functional_dependencies | | defined |
|
|
public | mcv_lists_arrays_stats | a, b, c FROM mcv_lists_arrays | | | defined
|
|
public | mcv_lists_bool_stats | a, b, c FROM mcv_lists_bool | | | defined
|
|
public | mcv_lists_stats | a, b, d FROM mcv_lists | | | defined
|
|
public | stts_hoge | col1, col2, col3 FROM stts_t3 | defined | defined | defined
|
|
public | stts_t1_a_b_stat | a, b FROM stts_t1 | defined | |
|
|
public | stts_t1_a_b_stat1 | a, b FROM stts_t1 | defined | defined |
|
|
public | stts_t1_a_b_stat2 | a, b FROM stts_t1 | defined | defined | defined
|
|
public | stts_t2_b_c_stat | b, c FROM stts_t2 | defined | defined | defined
|
|
stts_s1 | stts_foo | col1, col2 FROM stts_t3 | defined | defined | defined
|
|
stts_s2 | stts_yama | col1, col3 FROM stts_t3 | | defined | defined
|
|
tststats | priv_test_stats | a, b FROM priv_test_tbl | | | defined
|
|
(12 rows)
|
|
|
|
\dX stts_t*
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
--------+-------------------+-------------------+-----------+--------------+---------
|
|
public | stts_t1_a_b_stat | a, b FROM stts_t1 | defined | |
|
|
public | stts_t1_a_b_stat1 | a, b FROM stts_t1 | defined | defined |
|
|
public | stts_t1_a_b_stat2 | a, b FROM stts_t1 | defined | defined | defined
|
|
public | stts_t2_b_c_stat | b, c FROM stts_t2 | defined | defined | defined
|
|
(4 rows)
|
|
|
|
\dX *stts_hoge
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
--------+-----------+-------------------------------+-----------+--------------+---------
|
|
public | stts_hoge | col1, col2, col3 FROM stts_t3 | defined | defined | defined
|
|
(1 row)
|
|
|
|
\dX+
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
----------+------------------------+------------------------------------------------------------------+-----------+--------------+---------
|
|
public | func_deps_stat | (a * 2), upper(b), (c + 1::numeric) FROM functional_dependencies | | defined |
|
|
public | mcv_lists_arrays_stats | a, b, c FROM mcv_lists_arrays | | | defined
|
|
public | mcv_lists_bool_stats | a, b, c FROM mcv_lists_bool | | | defined
|
|
public | mcv_lists_stats | a, b, d FROM mcv_lists | | | defined
|
|
public | stts_hoge | col1, col2, col3 FROM stts_t3 | defined | defined | defined
|
|
public | stts_t1_a_b_stat | a, b FROM stts_t1 | defined | |
|
|
public | stts_t1_a_b_stat1 | a, b FROM stts_t1 | defined | defined |
|
|
public | stts_t1_a_b_stat2 | a, b FROM stts_t1 | defined | defined | defined
|
|
public | stts_t2_b_c_stat | b, c FROM stts_t2 | defined | defined | defined
|
|
stts_s1 | stts_foo | col1, col2 FROM stts_t3 | defined | defined | defined
|
|
stts_s2 | stts_yama | col1, col3 FROM stts_t3 | | defined | defined
|
|
tststats | priv_test_stats | a, b FROM priv_test_tbl | | | defined
|
|
(12 rows)
|
|
|
|
\dX+ stts_t*
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
--------+-------------------+-------------------+-----------+--------------+---------
|
|
public | stts_t1_a_b_stat | a, b FROM stts_t1 | defined | |
|
|
public | stts_t1_a_b_stat1 | a, b FROM stts_t1 | defined | defined |
|
|
public | stts_t1_a_b_stat2 | a, b FROM stts_t1 | defined | defined | defined
|
|
public | stts_t2_b_c_stat | b, c FROM stts_t2 | defined | defined | defined
|
|
(4 rows)
|
|
|
|
\dX+ *stts_hoge
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
--------+-----------+-------------------------------+-----------+--------------+---------
|
|
public | stts_hoge | col1, col2, col3 FROM stts_t3 | defined | defined | defined
|
|
(1 row)
|
|
|
|
\dX+ stts_s2.stts_yama
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
---------+-----------+-------------------------+-----------+--------------+---------
|
|
stts_s2 | stts_yama | col1, col3 FROM stts_t3 | | defined | defined
|
|
(1 row)
|
|
|
|
create statistics (mcv) ON a, b, (a+b), (a-b) FROM stts_t1;
|
|
create statistics (mcv) ON a, b, (a+b), (a-b) FROM stts_t1;
|
|
create statistics (mcv) ON (a+b), (a-b) FROM stts_t1;
|
|
\dX stts_t*expr*
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
--------+-----------------------------+-------------------------------------+-----------+--------------+---------
|
|
public | stts_t1_a_b_expr_expr_stat | a, b, (a + b), (a - b) FROM stts_t1 | | | defined
|
|
public | stts_t1_a_b_expr_expr_stat1 | a, b, (a + b), (a - b) FROM stts_t1 | | | defined
|
|
public | stts_t1_expr_expr_stat | (a + b), (a - b) FROM stts_t1 | | | defined
|
|
(3 rows)
|
|
|
|
drop statistics stts_t1_a_b_expr_expr_stat;
|
|
drop statistics stts_t1_a_b_expr_expr_stat1;
|
|
drop statistics stts_t1_expr_expr_stat;
|
|
set search_path to public, stts_s1;
|
|
\dX
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
---------+------------------------+------------------------------------------------------------------+-----------+--------------+---------
|
|
public | func_deps_stat | (a * 2), upper(b), (c + 1::numeric) FROM functional_dependencies | | defined |
|
|
public | mcv_lists_arrays_stats | a, b, c FROM mcv_lists_arrays | | | defined
|
|
public | mcv_lists_bool_stats | a, b, c FROM mcv_lists_bool | | | defined
|
|
public | mcv_lists_stats | a, b, d FROM mcv_lists | | | defined
|
|
public | stts_hoge | col1, col2, col3 FROM stts_t3 | defined | defined | defined
|
|
public | stts_t1_a_b_stat | a, b FROM stts_t1 | defined | |
|
|
public | stts_t1_a_b_stat1 | a, b FROM stts_t1 | defined | defined |
|
|
public | stts_t1_a_b_stat2 | a, b FROM stts_t1 | defined | defined | defined
|
|
public | stts_t2_b_c_stat | b, c FROM stts_t2 | defined | defined | defined
|
|
stts_s1 | stts_foo | col1, col2 FROM stts_t3 | defined | defined | defined
|
|
(10 rows)
|
|
|
|
create role regress_stats_ext nosuperuser;
|
|
set role regress_stats_ext;
|
|
\dX
|
|
List of extended statistics
|
|
Schema | Name | Definition | Ndistinct | Dependencies | MCV
|
|
--------+------------------------+------------------------------------------------------------------+-----------+--------------+---------
|
|
public | func_deps_stat | (a * 2), upper(b), (c + 1::numeric) FROM functional_dependencies | | defined |
|
|
public | mcv_lists_arrays_stats | a, b, c FROM mcv_lists_arrays | | | defined
|
|
public | mcv_lists_bool_stats | a, b, c FROM mcv_lists_bool | | | defined
|
|
public | mcv_lists_stats | a, b, d FROM mcv_lists | | | defined
|
|
public | stts_hoge | col1, col2, col3 FROM stts_t3 | defined | defined | defined
|
|
public | stts_t1_a_b_stat | a, b FROM stts_t1 | defined | |
|
|
public | stts_t1_a_b_stat1 | a, b FROM stts_t1 | defined | defined |
|
|
public | stts_t1_a_b_stat2 | a, b FROM stts_t1 | defined | defined | defined
|
|
public | stts_t2_b_c_stat | b, c FROM stts_t2 | defined | defined | defined
|
|
(9 rows)
|
|
|
|
reset role;
|
|
drop table stts_t1, stts_t2, stts_t3;
|
|
drop schema stts_s1, stts_s2 cascade;
|
|
drop user regress_stats_ext;
|
|
reset search_path;
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-- User with no access
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CREATE USER regress_stats_user1;
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GRANT USAGE ON SCHEMA tststats TO regress_stats_user1;
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SET SESSION AUTHORIZATION regress_stats_user1;
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SELECT * FROM tststats.priv_test_tbl; -- Permission denied
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ERROR: permission denied for table priv_test_tbl
|
|
-- Check individual columns if we don't have table privilege
|
|
SELECT * FROM tststats.priv_test_tbl
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WHERE a = 1 and tststats.priv_test_tbl.* > (1, 1) is not null;
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|
ERROR: permission denied for table priv_test_tbl
|
|
-- Attempt to gain access using a leaky operator
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|
CREATE FUNCTION op_leak(int, int) RETURNS bool
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AS 'BEGIN RAISE NOTICE ''op_leak => %, %'', $1, $2; RETURN $1 < $2; END'
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LANGUAGE plpgsql;
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CREATE OPERATOR <<< (procedure = op_leak, leftarg = int, rightarg = int,
|
|
restrict = scalarltsel);
|
|
SELECT * FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Permission denied
|
|
ERROR: permission denied for table priv_test_tbl
|
|
DELETE FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Permission denied
|
|
ERROR: permission denied for table priv_test_tbl
|
|
-- Grant access via a security barrier view, but hide all data
|
|
RESET SESSION AUTHORIZATION;
|
|
CREATE VIEW tststats.priv_test_view WITH (security_barrier=true)
|
|
AS SELECT * FROM tststats.priv_test_tbl WHERE false;
|
|
GRANT SELECT, DELETE ON tststats.priv_test_view TO regress_stats_user1;
|
|
-- Should now have access via the view, but see nothing and leak nothing
|
|
SET SESSION AUTHORIZATION regress_stats_user1;
|
|
SELECT * FROM tststats.priv_test_view WHERE a <<< 0 AND b <<< 0; -- Should not leak
|
|
a | b
|
|
---+---
|
|
(0 rows)
|
|
|
|
DELETE FROM tststats.priv_test_view WHERE a <<< 0 AND b <<< 0; -- Should not leak
|
|
-- Grant table access, but hide all data with RLS
|
|
RESET SESSION AUTHORIZATION;
|
|
ALTER TABLE tststats.priv_test_tbl ENABLE ROW LEVEL SECURITY;
|
|
GRANT SELECT, DELETE ON tststats.priv_test_tbl TO regress_stats_user1;
|
|
-- Should now have direct table access, but see nothing and leak nothing
|
|
SET SESSION AUTHORIZATION regress_stats_user1;
|
|
SELECT * FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Should not leak
|
|
a | b
|
|
---+---
|
|
(0 rows)
|
|
|
|
DELETE FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Should not leak
|
|
-- privilege checks for pg_stats_ext and pg_stats_ext_exprs
|
|
RESET SESSION AUTHORIZATION;
|
|
CREATE TABLE stats_ext_tbl (id INT PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY, col TEXT);
|
|
INSERT INTO stats_ext_tbl (col) VALUES ('secret'), ('secret'), ('very secret');
|
|
CREATE STATISTICS s_col ON id, col FROM stats_ext_tbl;
|
|
CREATE STATISTICS s_expr ON mod(id, 2), lower(col) FROM stats_ext_tbl;
|
|
ANALYZE stats_ext_tbl;
|
|
-- unprivileged role should not have access
|
|
SET SESSION AUTHORIZATION regress_stats_user1;
|
|
SELECT statistics_name, most_common_vals FROM pg_stats_ext x
|
|
WHERE tablename = 'stats_ext_tbl' ORDER BY ROW(x.*);
|
|
statistics_name | most_common_vals
|
|
-----------------+------------------
|
|
(0 rows)
|
|
|
|
SELECT statistics_name, most_common_vals FROM pg_stats_ext_exprs x
|
|
WHERE tablename = 'stats_ext_tbl' ORDER BY ROW(x.*);
|
|
statistics_name | most_common_vals
|
|
-----------------+------------------
|
|
(0 rows)
|
|
|
|
-- give unprivileged role ownership of table
|
|
RESET SESSION AUTHORIZATION;
|
|
ALTER TABLE stats_ext_tbl OWNER TO regress_stats_user1;
|
|
-- unprivileged role should now have access
|
|
SET SESSION AUTHORIZATION regress_stats_user1;
|
|
SELECT statistics_name, most_common_vals FROM pg_stats_ext x
|
|
WHERE tablename = 'stats_ext_tbl' ORDER BY ROW(x.*);
|
|
statistics_name | most_common_vals
|
|
-----------------+-------------------------------------------
|
|
s_col | {{1,secret},{2,secret},{3,"very secret"}}
|
|
s_expr | {{0,secret},{1,secret},{1,"very secret"}}
|
|
(2 rows)
|
|
|
|
SELECT statistics_name, most_common_vals FROM pg_stats_ext_exprs x
|
|
WHERE tablename = 'stats_ext_tbl' ORDER BY ROW(x.*);
|
|
statistics_name | most_common_vals
|
|
-----------------+------------------
|
|
s_expr | {secret}
|
|
s_expr | {1}
|
|
(2 rows)
|
|
|
|
-- Tidy up
|
|
DROP OPERATOR <<< (int, int);
|
|
DROP FUNCTION op_leak(int, int);
|
|
RESET SESSION AUTHORIZATION;
|
|
DROP TABLE stats_ext_tbl;
|
|
DROP SCHEMA tststats CASCADE;
|
|
NOTICE: drop cascades to 2 other objects
|
|
DETAIL: drop cascades to table tststats.priv_test_tbl
|
|
drop cascades to view tststats.priv_test_view
|
|
DROP USER regress_stats_user1;
|