On Thu, Oct 03, 2002 at 19:30:59 -0700, Josh Berkus <[EMAIL PROTECTED]> wrote: > Vincent, > > > SELECT * FROM TABLE1 ORDER BY X DESC, Y ASC; > > > > (X is a date and Y a varchar) > > > > What would that index be? > > > > Is there a function I can use, to invert x (the date), so that I can > > make a query / index set like : > > PostgreSQL's sorting mechanism can use an index either ascending or > descending; it does not make a difference.
Note this is referring to a multicolumn index. To use all columns of a multicolumn index the sort directions all need to be the same. However you are right to point out that this may not be a big deal for many applications where using the index on the first column gets the majority of the speed up. ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
