Mark Kirkwood <markir@xxxxxxxxxxxxxxx> writes: > Jim C. Nasby wrote: >> Good point. :/ I'm guessing there's no easy way to see how many blocks >> for a given relation are in shared memory, either... > contrib/pg_buffercache will tell you this - I think the key word in Jim's comment was "easy", ie, cheap. Grovelling through many thousands of buffers to count the matches to a given relation doesn't sound appetizing, especially not if it gets done over again several times during each query-planning cycle. Trying to keep centralized counts somewhere would be even worse (because of locking/ contention issues). regards, tom lane
