Ok I see. So what's the best way to find optimum value for various memory-related setting of postgresql ?
On Tue, Jan 20, 2009 at 3:27 PM, Albe Laurenz <laurenz.a...@wien.gv.at>wrote: > > I wonder how to find how much postgresql memory consumption > > is (real, not allocated) ? > > You could install the pg_buffercache contrib and > > SELECT pg_size_pretty( > CAST(current_setting('block_size') AS integer) * max(bufferid) > ) > FROM pg_buffercache WHERE relfilenode IS NOT NULL; > > to find out how much of the shared memory in the buffer pool is > actually in use. > > There is some extra shared memory that is used for other purposes, > and there is private memory of the backends (the latter could be > a significant number). > > Why do you want that number? > If it is for tuning of shared_buffers, that is probably a bad way. > Even if shared_buffers is set much higher than you'd actually need > it, sooner or later all of your shared_buffers will be used, unless > your database is tiny. > > Yours, > Laurenz Albe >