I'm sorry, I realized after posting this that it went to the wrong list, I resent it to pgsql-sql instead.
But basically I haven't done any ANALYZE or EXPLAIN yet because of the fact that the order -is- making a difference so it can't be executing the same query inside the database engine. Given that, I figured I would jsut look for theories on how to rewrite the queries before submitting first. btw, we are using postgresql 7.1.2 compiled from source on rh linux 7.0. I also might not have been very clear about the fact that the user is basically constructing the query dynamically in the application, so it's not a matter of just optimizing any specifc query, but any possible query. Tom Lane [[EMAIL PROTECTED]] wrote: > Dav Coleman <[EMAIL PROTECTED]> writes: > > I have noticed that the semantically equivalent SQL queries can > > differ > > vastly in speed performance depending on the order of clauses ANDed > > together ( "WHERE cond1 AND cond2" takes forever, but "WHERE cond2 > > AND cond1" comes right back). > > Could we see a specific example? > > It would also be useful to know what PG version you are using, whether > you've VACUUM ANALYZEd the tables, and what EXPLAIN has to say about > your query. > > regards, tom lane -- Dav Coleman http://www.danger-island.com/dav/ -- Dav Coleman http://www.danger-island.com/dav/ ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
