Re: pg_autovacuum w/ dbt2 - Mailing list pgsql-hackers

From Matthew T. O'Connor
Subject Re: pg_autovacuum w/ dbt2
Date
Msg-id 41C8B6DC.5060502@zeut.net
Whole thread Raw
In response to Re: pg_autovacuum w/ dbt2  (Mark Wong <markw@osdl.org>)
List pgsql-hackers
Mark Wong wrote:

>The overall throughput is better for a run like this:
>    http://www.osdl.org/projects/dbt2dev/results/dev4-010/207/
>
>A drop from 3865 to 2679 (31%) by just adding pg_autovacuum.  That's
>what I meant by "not good". :)
>  
>
I would agree that is "not good" :-)  It sounds like pg_autovacuum is 
being to aggressive for this type of load, that is vacuuming more often 
than needed, however the lazy vacuum options were added so as to reduce 
the performance impact of running a vacuum while doing other things, so, 
I would recommend both higher autovacuum thresholds and trying out some 
of the lazy vacuum settings. 

>I'll start with the additional debug messages, with 8.0rc2, before
>I start changing the other settings, if that sounds good.
>

Sounds fine.  From Tom Lane's response, we have a backend bug that needs 
to be resolved and I think that is the priority.




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