mirror of
https://github.com/HypoPG/hypopg
synced 2026-05-24 09:38:21 +00:00
164 lines
4.3 KiB
Text
164 lines
4.3 KiB
Text
-- SETUP
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CREATE OR REPLACE FUNCTION do_explain(stmt text) RETURNS table(a text) AS
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$_$
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DECLARE
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ret text;
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BEGIN
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FOR ret IN EXECUTE format('EXPLAIN (FORMAT text) %s', stmt) LOOP
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a := ret;
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RETURN next ;
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END LOOP;
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END;
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$_$
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LANGUAGE plpgsql;
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CREATE EXTENSION hypopg;
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CREATE TABLE hypo (id integer, val text);
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INSERT INTO hypo SELECT i, 'line ' || i
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FROM generate_series(1,100000) f(i);
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ANALYZE hypo;
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-- TESTS
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SELECT COUNT(*) AS nb
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FROM public.hypopg_create_index('SELECT 1;CREATE INDEX ON hypo(id); SELECT 2');
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WARNING: hypopg: SQL order #1 is not a CREATE INDEX statement
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WARNING: hypopg: SQL order #3 is not a CREATE INDEX statement
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nb
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----
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1
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(1 row)
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SELECT nspname, relname, amname FROM public.hypopg_list_indexes();
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nspname | relname | amname
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---------+---------+--------
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public | hypo | btree
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(1 row)
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-- Should use hypothetical index
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SELECT COUNT(*) FROM do_explain('SELECT * FROM hypo WHERE id = 1') e
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WHERE e ~ 'Index.*<\d+>btree_hypo.*';
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count
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-------
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1
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(1 row)
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-- Should use hypothetical index
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SELECT COUNT(*) FROM do_explain('SELECT * FROM hypo ORDER BY id') e
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WHERE e ~ 'Index.*<\d+>btree_hypo.*';
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count
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-------
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1
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(1 row)
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-- Should not use hypothetical index
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SELECT COUNT(*) FROM do_explain('SELECT * FROM hypo') e
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WHERE e ~ 'Index.*<\d+>btree_hypo.*';
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count
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-------
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0
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(1 row)
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-- Add predicate index
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SELECT COUNT(*) AS nb
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FROM public.hypopg_create_index('CREATE INDEX ON hypo(id) WHERE id < 5');
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nb
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----
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1
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(1 row)
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-- This specific index should be used
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WITH ind AS (
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SELECT indexrelid, row_number() OVER (ORDER BY indexrelid) AS num
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FROM public.hypopg()
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),
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regexp AS (
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SELECT regexp_replace(e, '.*<(\d+)>.*', E'\\1', 'g') AS r
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FROM do_explain('SELECT * FROM hypo WHERE id < 3') AS e
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)
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SELECT num
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FROM ind
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JOIN regexp ON ind.indexrelid::text = regexp.r;
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num
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-----
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2
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(1 row)
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-- Specify fillfactor
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SELECT COUNT(*) AS NB
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FROM public.hypopg_create_index('CREATE INDEX ON hypo(id) WITH (fillfactor = 10)');
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nb
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----
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1
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(1 row)
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-- Specify an incorrect fillfactor
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SELECT COUNT(*) AS NB
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FROM public.hypopg_create_index('CREATE INDEX ON hypo(id) WITH (fillfactor = 1)');
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ERROR: value 1 out of bounds for option "fillfactor"
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DETAIL: Valid values are between "10" and "100".
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-- Index size estimation
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SELECT pg_size_pretty(hypopg_relation_size(indexrelid))
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FROM hypopg()
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ORDER BY indexrelid;
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pg_size_pretty
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----------------
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2544 kB
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8192 bytes
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4120 kB
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(3 rows)
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-- locally disable hypoopg
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SET hypopg.enabled to false;
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-- no hypothetical index should be used
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SELECT COUNT(*) FROM do_explain('SELECT * FROM hypo WHERE id = 1') e
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WHERE e ~ 'Index.*<\d+>btree_hypo.*';
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count
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-------
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0
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(1 row)
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-- locally re-enable hypoopg
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SET hypopg.enabled to true;
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-- hypothetical index should be used
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SELECT COUNT(*) FROM do_explain('SELECT * FROM hypo WHERE id = 1') e
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WHERE e ~ 'Index.*<\d+>btree_hypo.*';
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count
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-------
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1
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(1 row)
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-- Remove one hypothetical index
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SELECT hypopg_drop_index(indexrelid) FROM hypopg() ORDER BY indexrelid LIMIT 1;
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hypopg_drop_index
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-------------------
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t
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(1 row)
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-- Remove all the hypothetical indexes
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SELECT hypopg_reset();
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hypopg_reset
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--------------
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(1 row)
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-- index on expression
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SELECT COUNT(*) AS NB
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FROM public.hypopg_create_index('CREATE INDEX ON hypo (md5(val))');
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nb
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----
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1
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(1 row)
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-- Should use hypothetical index
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SELECT COUNT(*) FROM do_explain('SELECT * FROM hypo WHERE md5(val) = md5(''line 1'')') e
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WHERE e ~ 'Index.*<\d+>btree_hypo.*';
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count
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-------
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1
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(1 row)
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-- Deparse an index DDL, with almost every possible pathcode
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SELECT hypopg_get_indexdef(indexrelid) FROM hypopg_create_index('create index on hypo using btree(id desc, id desc nulls first, id desc nulls last, cast(md5(val) as bpchar) bpchar_pattern_ops) with (fillfactor = 10) WHERE id < 1000 AND id +1 %2 = 3');
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hypopg_get_indexdef
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---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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CREATE INDEX ON public.hypo USING btree (id DESC, id DESC, id DESC NULLS LAST, ((md5(val))::bpchar) bpchar_pattern_ops) WITH (fillfactor = 10) WHERE ((id < 1000) AND ((id + (1 % 2)) = 3))
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(1 row)
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