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. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
