On Fri, 30 May 2003, Bruno Wolff III wrote: > Now that expressions can be used in indexes in 7.4 you can have multicolumn > indexes that are ordered in different directions. However the planner > doesn't seem to understand that order by -col asc is the same as order by > col desc (for at least the normal -) so you have to be careful how you > write queries when doing this.
I think it'd be better to make it easier to make indexes where some columns are reversed. I'm not sure that making a reverse opclass for btree (one that goes >, >=, =, <=, < I guess) is a complete solution even for btree but if it is, we could provide them. I think this would also have the advantage of not requiring wacky queries to use the index for multicolumn lookups as well. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
