Re: [Bizgres-general] A Guide to Constraint Exclusion (
Luke Lonergan <llonergan@greenplum.com>
From: "Luke Lonergan" <llonergan@greenplum.com>
To: "Simon Riggs" <simon@2ndquadrant.com>, hannu@skype.net
Cc: "bizgres-general" <bizgres-general@pgfoundry.org>, pgsql-hackers@postgresql.org
Date: 2005-07-14T21:13:17Z
Lists: pgsql-hackers
>>> CE checks will not currently recognise STABLE functions within a query. >>> So WHERE clauses such as >>> DateKey > CURRENT DATE >>> will not cause exclusion because CURRENT DATE is a STABLE function. >>> >>> CE checks are not made when the parent table is involved in a join. >> >> Is this also the case where parent table is inside subquery and that >> subquery is involved in a join? > > My comment was too terse. What I meant was that you can't do dynamic > exclusion based upon the results of a join. i.e. PPUC2 Phew! Correlated subqueries won't CE then, but the more common complex queries will. We'll test with some common ones soon. - Luke