Re: Recheck condition

On Wed, Nov 28, 2007 at 01:18:56PM -0500, Josh Harrison wrote:
> Hi,
> Sorry if my question is silly.
> When I use explain analyze command I come across 'recheck condition' in some
> places.
> I googled for this but didn't get any solid answers.

Some indexes are inexact, i.e. they may sometimes return tuples that
don't actually match the index condition. This also happens with bitmap
scans, because it'll return anything in the bitmap which will probably
be more than what you asked for. The recheck just means that the
planner retests the index condition on the result to make sure you only
get the rows you wanted.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Those who make peaceful revolution impossible will make violent revolution inevitable.
> -- John F Kennedy