On Thu, Jun 05, 2014 at 02:12:33AM +0200, Andres Freund wrote: > On 2014-06-04 20:04:07 -0400, Noah Misch wrote: > > On Wed, Jun 04, 2014 at 10:14:42AM -0400, Tom Lane wrote: > > > It's possible that we could apply the optimization only to queries that > > > have been issued directly by a client, but that seems rather ugly and > > > surprise-filled. > > > > ... such as this idea. It's a good start to a fairly-hard problem. FKs are > > also always valid when afterTriggers->query_depth == -1, such as when all > > ongoing queries qualified for EXEC_FLAG_SKIP_TRIGGERS. What else? We could > > teach trigger.c to efficiently report whether a given table has a queued RI > > trigger. Having done that, when plancache.c is building a custom plan, the > > planner could ignore FKs with pending RI checks and use the rest. At that > > point, the surprises will be reasonably-isolated. > > A bit more crazy, but how about trying trying to plan joins with a added > one-time qual that checks the size of the deferred trigger queue? Then > we wouldn't even need special case plans.
That, too, sounds promising to investigate. -- Noah Misch EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
