"Sergey Konoplev" <gray.ru@xxxxxxxxx> writes: > I've faced strange parser (or may be planner) behaviour. When I do > "EXPLAIN SELECT 1 FROM table1 WHERE table1_id IN (...~2000 ids > here...);" it works as fast as I expect (50 ms). But when I rewrite it > using NOT IN "EXPLAIN SELECT 1 FROM table1 WHERE table1_id NOT IN > (...~2000 ids here...);" it gets much more slower (34537 ms). FWIW, I can't reproduce your problem here. The output from your script looks like this: ------------------------------------------ Testing EXPLAIN w/ NOT IN... ------------------------------------------ 100 ids: 16 ms 200 ids: 17 ms 300 ids: 17 ms 400 ids: 18 ms 500 ids: 19 ms 600 ids: 20 ms 700 ids: 21 ms 800 ids: 22 ms 900 ids: 23 ms 1000 ids: 24 ms 1100 ids: 25 ms 1200 ids: 25 ms 1300 ids: 26 ms 1400 ids: 28 ms 1500 ids: 28 ms 1600 ids: 29 ms 1700 ids: 30 ms 1800 ids: 31 ms 1900 ids: 32 ms 2000 ids: 33 ms ------------------------------------------ Testing EXPLAIN w/ IN... ------------------------------------------ 100 ids: 16 ms 200 ids: 17 ms 300 ids: 18 ms 400 ids: 19 ms 500 ids: 20 ms 600 ids: 21 ms 700 ids: 22 ms 800 ids: 23 ms 900 ids: 24 ms 1000 ids: 25 ms 1100 ids: 26 ms 1200 ids: 27 ms 1300 ids: 29 ms 1400 ids: 29 ms 1500 ids: 31 ms 1600 ids: 32 ms 1700 ids: 32 ms 1800 ids: 34 ms 1900 ids: 35 ms 2000 ids: 36 ms regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
