Hi, I'm having a performance problem in postgresql.
I have a rather complex view (attached) which, on itself, executes very fast, as it should. Normally this view is unordered. When I order the view itself (see comments in attachment), the view executes with about the same speed since the field i'm sorting on has an index. However, i dont want the view to be presorted, but sort it in the queries that use the view. When I do that, the index I have on that field seems to be ignored. It stretches so far that, when I sort the view on A and sort the query on A too, the query will try to sort _again_ _without_ index and thus lose all performance. I've attached the query-plans for the different cases. preordered: means the view itself is sorted with/without sorting: tells whether the query is sorted Note: the "NOT NULL" in the queries doesn't affect performance With kind regards, Mathieu ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org