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--
-- Test deallocation of entries
--
SHOW pg_stat_statements.max;
SET pg_stat_statements.track = 'all';
-- Create 101 tables.
DO $$
BEGIN
FOR i IN 1..101 LOOP
EXECUTE format('create table t%s (a int)', lpad(i::text, 3, '0'));
END LOOP;
END
$$;
SELECT pg_stat_statements_reset() IS NOT NULL AS t;
-- Run 98 queries.
DO $$
BEGIN
FOR i IN 1..98 LOOP
EXECUTE format('select * from t%s', lpad(i::text, 3, '0'));
END LOOP;
END
$$;
-- All 98 queries should be registered. We just check the first and
-- last to keep the output small.
SELECT query FROM pg_stat_statements WHERE query LIKE '%t001%' OR query LIKE '%t098%' ORDER BY query;
-- Query tables 2 through 98 again, so they have a higher calls count.
-- Table 1 still has previous calls count.
DO $$
BEGIN
FOR i IN 2..98 LOOP
EXECUTE format('select * from t%s', lpad(i::text, 3, '0'));
END LOOP;
END
$$;
-- Run 3 more queries. This will exceed the max and will cause the
-- least used query to be deallocated. (The queries for
-- pg_stat_statements themselves will also register, so fewer than 3
-- queries will also cause overflow, but let's keep this scenario
-- self-contained.)
DO $$
BEGIN
FOR i IN 99..101 LOOP
EXECUTE format('select * from t%s', lpad(i::text, 3, '0'));
END LOOP;
END
$$;
-- Check that the limit was kept.
SELECT count(*) <= 100 FROM pg_stat_statements;
-- Check that record for t001 has been deallocated.
SELECT query FROM pg_stat_statements WHERE query LIKE '%t001%' ORDER BY query;
-- Check deallocation count.
SELECT dealloc > 0 AS t FROM pg_stat_statements_info;
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