On Fri, 23 Apr 2004, Antal Attila wrote: > Hi! > > We have a complex problematic area. What is the simplest solution for > the next query type: > > SELECT * FROM tablename ORDER BY col1 ASC, col2 DESC; > > In our experience, postgres cannot use a multi-colum index on (col1, > col2) in this situation, becouse there are different directions after > ORDER BY. Is custom operator class the easiest solution, which can solve > the reverse indexing on col2? Our problem with this solution, is that we > have to replace "DESC" with "USING myoperator". Is it possible, that > postgres can recognize "myoperator" without replacing "DESC"?
Yes. You should be able to make an opclass where the operators are the standard operators but in a different order which should get used when doing DESC. I think there should be examples in the archives. ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
