(re-post) Dear list,
Please let me know if this is not the list to ask this kind of question. I am trying to optimize a query that joins two relatively large (750000 rows in each) tables. If I do it using a subselect, I can "force" the planner to choose the fastest path. Now, my question is: If I have a subselect with an ORDER BY, and I LEFT JOIN the result with the other table, is the order maintained? Or is PostgreSQL free to return the rows in any order, after the join? My query is the following: SELECT a.* FROM (SELECT * FROM tree WHERE parent_id=1363405 ORDER BY order_index DESC) AS a LEFT JOIN content AS b ON a.object_id=b.id WHERE (b.onair = 't') LIMIT 1; Thanks, Morten -- Morten K. Poulsen <[EMAIL PROTECTED]> http://www.afdelingp.dk/ ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
