"Alexei" <[EMAIL PROTECTED]> writes: > .... Although the result > of the query always was correct whichever plan it's using. I repete - I did > not do anything between queries, but just ran the same 'explain select ...' > sequentially. The query itself is heavy, but pretty strightforward - 2 > tables joined 12 times.
With 12 tables you'll be using the geqo optimizer by default, and it has a random component to the plans by design. It's a bit disappointing that it doesn't consistently find plans of about the same quality though. Can you provide a complete test case? (No, the bare text of a query isn't a test case...) regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings