-- tests for tidscans CREATE TABLE tidscan(id integer); -- only insert a few rows, we don't want to spill onto a second table page INSERT INTO tidscan VALUES (1), (2), (3); -- show ctids -- XXX since rows come from different datanodes, some TIDs can be duplicated in -- XL SELECT ctid, * FROM tidscan; -- ctid equality - implemented as tidscan EXPLAIN (COSTS OFF) SELECT ctid, * FROM tidscan WHERE ctid = '(0,1)'; SELECT ctid, * FROM tidscan WHERE ctid = '(0,1)'; EXPLAIN (COSTS OFF) SELECT ctid, * FROM tidscan WHERE '(0,1)' = ctid; SELECT ctid, * FROM tidscan WHERE '(0,1)' = ctid; -- ctid = ScalarArrayOp - implemented as tidscan EXPLAIN (COSTS OFF) SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]); SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]); -- ctid != ScalarArrayOp - can't be implemented as tidscan EXPLAIN (COSTS OFF) SELECT ctid, * FROM tidscan WHERE ctid != ANY(ARRAY['(0,1)', '(0,2)']::tid[]); SELECT ctid, * FROM tidscan WHERE ctid != ANY(ARRAY['(0,1)', '(0,2)']::tid[]); -- tid equality extracted from sub-AND clauses EXPLAIN (COSTS OFF) SELECT ctid, * FROM tidscan WHERE (id = 3 AND ctid IN ('(0,2)', '(0,3)')) OR (ctid = '(0,1)' AND id = 1); SELECT ctid, * FROM tidscan WHERE (id = 3 AND ctid IN ('(0,2)', '(0,3)')) OR (ctid = '(0,1)' AND id = 1); -- exercise backward scan and rewind BEGIN; DECLARE c CURSOR FOR SELECT ctid, * FROM tidscan WHERE ctid = ANY(ARRAY['(0,1)', '(0,2)']::tid[]); FETCH ALL FROM c; -- XL does not support BACKWARD scan of RemoteSubplan/RemoteSubquery and -- hence the next statement fails FETCH BACKWARD 1 FROM c; FETCH FIRST FROM c; ROLLBACK; -- tidscan via CURRENT OF BEGIN; DECLARE c CURSOR FOR SELECT ctid, * FROM tidscan; FETCH NEXT FROM c; -- skip one row FETCH NEXT FROM c; -- perform update EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF) -- XL does not support WHERE CURRENT OF and hence the next -- statement fails UPDATE tidscan SET id = -id WHERE CURRENT OF c RETURNING *; FETCH NEXT FROM c; -- perform update EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF) UPDATE tidscan SET id = -id WHERE CURRENT OF c RETURNING *; SELECT * FROM tidscan; -- position cursor past any rows FETCH NEXT FROM c; -- should error out EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF) UPDATE tidscan SET id = -id WHERE CURRENT OF c RETURNING *; ROLLBACK; DROP TABLE tidscan;