Robert Treat <xzilla(at)users(dot)sourceforge(dot)net> writes:
> I think the thread you're thinking of is on or about this post:
> http://archives.postgresql.org/pgsql-patches/2003-12/msg00039.php
> Manfred Koizar produced a patch that modified index correlation by
> sorting equal key values based on item pointers. The patch went as far
> as getting accepted into the patch queue, but Tom raised some doubts
> about it and it was subsequently removed.
Hm, that had nothing to do with multi-column correlation though.
I'm at a loss to think of any work that matches with Josh's
recollection.
regards, tom lane