On Thu, 29 Jan 2004, Bruno Wolff III wrote: > On Thu, Jan 29, 2004 at 15:29:11 +0200, > Achilleus Mantzios <[EMAIL PROTECTED]> wrote: > > O kyrios Bruno Wolff III egrapse stis Jan 29, 2004 : > > > > As i see there was a thread > > http://archives.postgresql.org/pgsql-hackers/2003-05/msg00762.php > > dealing with this issue, assuming the "correct" order by > > should be "order by datetime ASC, id DESC". > > So you really didn't want them in the reverse order? > > > Do you know of any progress for declaring the direction of each > > column in a multicolumn index? > > If you are using 7.4 you can use a functional index to get around this. > Assuming id is a numeric type, you can make an index on datetime and > (-id) and sort by datetime, -id and the index should get used. > > This should still get fixed at some point, as this trick doesn't work > for types for which the - operator exists. But I haven't heard of > anyone working on it for 7.5, so don't expect a real fix any time soon.
I'd thought that I'd previously sent a message containing a set of definitions for the reverse opclasses (not meant for inclusion to the system because I was making SQL functions that basically did -<normal comparison function> to use as the function of the operator class, but possibly worth playing with) but now that I actually search again, I don't see it. ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings