On Fri, 2007-04-13 at 18:48 -0400, Tom Lane wrote:
> Has anyone got any thoughts about the best way to do this?
I don't think we know enough to pick one variant that works in all
cases. This requires more detailed analysis of various cases.
Lets put in a parameter to allow the options to be varied. The purpose
would be to look for some more information that allows us to see what
the pre-conditions would be for each heuristic.
Initially, we say this is a beta-only feature and may be withdrawn in
the production version.
Why did it not pick my index? is a tiring game, but one that must be
played. I hope that the ORDER LIMIT optimization should reduce the
number of indexes chosen to maintain sort order in the output.
-- Simon Riggs EnterpriseDB http://www.enterprisedb.com