Tom Lane wrote:
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).
Yeah - not sensible for a transaction oriented system - might be ok for
DSS tho.
Cheers
mark
