-- create a normal heap table and insert some rows. -- use a temp table so that vacuum behavior doesn't depend on global xmin create temp table htab (a int); insertinto htab values (100), (200), (300), (400), (500);
-- test empty TID array select heap_force_freeze('htab'::regclass, ARRAY[]::tid[]);
-- nothing should be frozen yet select * from htab where xmin = 2;
-- should be gone now select * from htab where ctid = '(0, 4)';
-- should now be skipped because it's already dead select heap_force_kill('htab'::regclass, ARRAY['(0, 4)']::tid[]); select heap_force_freeze('htab'::regclass, ARRAY['(0, 4)']::tid[]);
-- freeze two TIDs at once while skipping an out-of-range block number select heap_force_freeze('htab'::regclass,
ARRAY['(0, 1)', '(0, 3)', '(1, 1)']::tid[]);
-- we should now have two frozen tuples select ctid, xmax from htab where xmin = 2;
-- out-of-range TIDs should be skipped select heap_force_freeze('htab'::regclass, ARRAY['(0, 0)', '(0, 6)']::tid[]);
-- set up a new table with a redirected line pointer -- use a temp table so that vacuum behavior doesn't depend on global xmin create temp table htab2(a int); insertinto htab2 values (100); update htab2 set a = 200;
vacuum htab2;
-- redirected TIDs should be skipped select heap_force_kill('htab2'::regclass, ARRAY['(0, 1)']::tid[]);
-- now create an unused line pointer select ctid from htab2; update htab2 set a = 300; select ctid from htab2;
vacuum freeze htab2;
-- unused TIDs should be skipped select heap_force_kill('htab2'::regclass, ARRAY['(0, 2)']::tid[]);
-- multidimensional TID array should be rejected select heap_force_kill('htab2'::regclass, ARRAY[['(0, 2)']]::tid[]);
-- TID array with nulls should be rejected select heap_force_kill('htab2'::regclass, ARRAY[NULL]::tid[]);
-- but we should be able to kill the one tuple we have select heap_force_kill('htab2'::regclass, ARRAY['(0, 3)']::tid[]);
-- materialized view. -- note that we don't commit the transaction, so autovacuum can't interfere.
begin; create materialized view mvw asselect a from generate_series(1, 3) a;
select * from mvw where xmin = 2; select heap_force_freeze('mvw'::regclass, ARRAY['(0, 3)']::tid[]); select * from mvw where xmin = 2;
select heap_force_kill('mvw'::regclass, ARRAY['(0, 3)']::tid[]); select * from mvw where ctid = '(0, 3)';
rollback;
-- check that it fails on an unsupported relkind create view vw asselect1; select heap_force_kill('vw'::regclass, ARRAY['(0, 1)']::tid[]); select heap_force_freeze('vw'::regclass, ARRAY['(0, 1)']::tid[]);
-- cleanup. drop view vw; drop extension pg_surgery;
Messung V0.5 in Prozent
¤ Dauer der Verarbeitung: 0.10 Sekunden
(vorverarbeitet am 2026-08-08)
¤
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