Re: Do we still need constraint_exclusion?

On Wed, 2009-01-07 at 17:46 -0500, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> >> * Simon Riggs (simon@2ndQuadrant.com) wrote:
> >>> I don't really understand this. Who can set up an inherited table
> >>> structure but can't remember to turn on constraint_exclusion?
> 
> > This new change also adds the constraint exclusion overhead only for
> > inhertance (by default) so it should slightly improve query peformance.
> 
> Right, I think that's the real winning argument for having this: it
> gets the benefit of c_e for partitioned tables without imposing overhead
> for non-partitioned tables.  See Josh B's remarks upthread about
> actually going to the trouble of turning c_e off and on on-the-fly to
> try to approximate that result.

OK, now that's a winning argument. Go for it.

-- Simon Riggs           www.2ndQuadrant.comPostgreSQL Training, Services and Support