On Thu, Aug 10, 2006 at 10:23:55AM +0100, Richard Huxton wrote: > Carl Youngblood wrote: > >- I noticed that there are six different postmaster daemons running. > >Only one of them is taking up a lot of RAM (1076m virtual and 584m > >resident). The second one is using 181m resident while the others are > >less than 20m each. Is it normal to have multiple postmaster > >processes? > > You should have one master backend process and one per connection. PG is > a classic multi-process designed server. > > > Even the biggest process doesn't seem to be using near as > >much RAM as I have on this machine. Is that bad? What percentage of > >my physical memory should I expect postgres to use for itself? How > >can I encourage it to cache more query results in memory? > > OK - one of the key things with PostgreSQL is that it relies on the O.S. > to cache its disk files. So, allocating too much memory to PG can be > counterproductive. > > From your figures, you're allocating about 64MB to work_mem, which is > per sort. So, a complex query could use several times that amount. If > you don't have many concurrent queries that might be what you want. > > Also, you've allocated 1GB to your shared_buffers which is more than I'd > use as a starting point. See the recent thread about how old rules of thumb for shared_buffers are now completely bunk. With 4G of memory, setting shared_buffers to 2G could easily be reasonable. The OP really needs to test several different values with their actual workload and see what works best. > You've only mentioned one main table with 100,000 rows, so presumably > you're going to cache the entire DB in RAM. So, you'll want to increase > effective_cache_size and reduce random_page_cost. > > -- > Richard Huxton > Archonet Ltd > > ---------------------------(end of broadcast)--------------------------- > TIP 2: Don't 'kill -9' the postmaster > -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
