On Sun, 2005-03-20 at 12:28 -0500, Tom Lane wrote: > > Removing FlushRelationBuffers in those circumstances will save a scan of > > shared_buffers, but will it save I/O? Perhaps not, but I care more about > > the O(N) operation on shared_buffers than I do about the I/O. > > Realistically, wasted I/O costs more. But yeah, saving one scan of the > buffer arena is a nice side benefit.
3-4 years ago, I'd have said definitely true. I'm seeing servers with enough RAM to swallow databases whole and people willing to allocate that all to their DBMS. People try to avoid the I/O, but do that by upping the allocations. I guess my vision is for these kind of parameters and much beyond... shared_buffers = 4000000 max_fsm_pages = 1000000 so the O(N) stuff matters... but I realise I'm following Amdahl's Law to the point where there's nothing significant left to care about. Best Regards, Simon Riggs ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
