Re: Offering tuned config files
Daniel Kalchev <daniel@digsys.bg>
From: Daniel Kalchev <daniel@digsys.bg>
To: Manfred Koizar <mkoi-pg@aon.at>
Cc: "PostgresSQL Hackers Mailing List" <pgsql-hackers@postgresql.org>
Date: 2003-02-14T12:24:23Z
Lists: pgsql-hackers
>>>Manfred Koizar said: > effective_cache_size = 20000 (~ 160 MB) should be more adequate for a > 256 MB machine than the extremely conservative default of 1000. I > admit that the effect of this change is hard to benchmark. A way too > low (or too high) setting may lead the planner to wrong conclusions. The default on BSD systems is 10% of the total RAM, so on a 256MB machine this would be ~26MB or effective_cache_size = 32000. One could always modify the kernel to support much larger value, but I doubt this is done in many cases and the usefulness of larger buffer cache is not obvious in the presence of many fsync calls (which might be typicall). I could be wrong, of course :) In any case, the default is indeed low and would prevent using indexes on larger tables, where they are most useful. Daniel