mirror of
https://github.com/postgres/postgres.git
synced 2026-02-18 10:09:35 -05:00
be6c3d19fd
TidScan plan nodes were not systematically tested before. These additions raise the LOC coverage number for the basic regression tests from 52% to 92% in nodeTidscan.c, and from 60% to 93% in tidpath.c. Andres Freund, tweaked a bit by me Discussion: https://postgr.es/m/20170320062511.hp5qeurtxrwsvfxr@alap3.anarazel.de
66 lines
2.1 KiB
PL/PgSQL
66 lines
2.1 KiB
PL/PgSQL
-- 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
|
|
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;
|
|
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)
|
|
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;
|