# Test SKIP LOCKED with tuple locks. setup { CREATE TABLE queue ( id int PRIMARY KEY, data text NOT NULL, status text NOT NULL ); INSERT INTO queue VALUES (1, 'foo', 'NEW'), (2, 'bar', 'NEW'); } teardown { DROP TABLE queue; } session "s1" setup { BEGIN; } step "s1a" { SELECT * FROM queue ORDER BY id FOR UPDATE LIMIT 1; } step "s1b" { COMMIT; } session "s2" setup { BEGIN; } step "s2a" { SELECT * FROM queue ORDER BY id FOR UPDATE LIMIT 1; } step "s2b" { COMMIT; } session "s3" setup { BEGIN; } step "s3a" { SELECT * FROM queue ORDER BY id FOR UPDATE SKIP LOCKED LIMIT 1; } step "s3b" { COMMIT; } # s3 skips to the second record because it can't obtain the tuple lock # (s2 holds the tuple lock because it is next in line to obtain the # row lock, and s1 holds the row lock) permutation "s1a" "s2a" "s3a" "s1b" "s2b" "s3b"