Bob Jolliffe <bobjolliffe@xxxxxxxxx> writes: > We do know that max_connections is set quite high (600) when we don't > really expect more than 100. I wonder does the planner take > max_connections x work_mem into account when considering the memory it > has potentially available? No. There have been discussions to the effect that it ought to have a more holistic view about available memory; but nothing's been done about that, and certainly no existing release does so. Usually the proximate cause of bad plan choices is bad rowcount estimates --- you can spot that by comparing estimated and actual rowcounts in EXPLAIN ANALYZE results. regards, tom lane
