On Sun, 2004-10-03 at 21:01, Gaetano Mendola wrote:
Tom Lane wrote:
Gaetano Mendola <[EMAIL PROTECTED]> writes:
Christopher Browne wrote: pg_autovacuum -d 3 -v 300 -V 0.5 -S 0.8 -a 200 -A 0.8
I'm not very familiar at all with appropriate settings for
autovacuum,
but doesn't the above say to vacuum a table only when the dead space reaches 50%? That seems awfully lax to me. I've always thought one should vacuum often enough to keep dead space to maybe 10 to 25%.
Yes that is what those options say. The default values are even more lax. I wasn't sure how best to set them, I erred on the conservative side.
The problem is that I can not set these value per table and per
database
so, I had to find some compromise, however I will test in the next
days
what happen with -V 0.2
However each six hour I perform a vacuum on all database and the HD
space
continue to grow even with FSM parameters large enough.
Since you are running autovacuum I doubt the doing vacuumdb -a -z is 3 times a day buying you much. It's not a bad idea to do once in a while.
The reason is that I have few tables of about 5 milion with ~ 10000 insert per day. Even with setting -v 300 -V 0.1 this means these tables will be analyzed each 50 days. So I have to force it.
Regards Gaetano Mendola
Given the way Postgres works, it is normal to have slack space in your tables. The real question is do your table stop growing? At some point you should reach a stead state where you have some percentage of slack space that stops growing.
You said that after running for a week you have 400M of reclaimable space. Is that a problem? If you don't do a vacuum full for two weeks is it still 400M? My guess is most of the 400M is created in the first few hours (perhaps days) after running your vacuum full.
Matthew
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