Forum OpenACS Q&A: Re: Problem

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4: Re: Problem (response to 3)
Posted by Jeff Davis on
I have seen something like 8-15% of physical memory for shared buffers on the pgsql-performance list. As for sortmem, I think 2mb is probably too small unless you are running a really small site or are sharing the server with a lot of other aolserver instances. It's probably really hard to make a firm recommendation for sort_mem, but I would err on the side of making it a little to large and setting it lower if you see the server thrashing.

Keep in mind that what happens of you have queries that go over the sort_mem size they use an on disk sort (or use queru plans which do table scans rather than has joins for example) which can have a tremendous negative impact on performance as well.