=?UTF-8?Q?Grzegorz_Ja=C5=9Bkiewicz?= <gryzman@xxxxxxxxx> writes: > I mean query like: > select id from foo where id not in ( select id from bar); > into: > select f.id from foo f left join bar b on f.id=b.id where b.id is null; Postgres does not do that, because they don't mean the same thing --- the behavior for NULLs in bar.id is different. 8.4 does understand that NOT EXISTS is an antijoin, though. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
