Re: Out of Memory - 8.2.4 - Mailing list pgsql-general

From Alvaro Herrera
Subject Re: Out of Memory - 8.2.4
Date
Msg-id 20070828224001.GC22033@alvh.no-ip.org
Whole thread Raw
In response to Re: Out of Memory - 8.2.4  (Erik Jones <erik@myemma.com>)
List pgsql-general
Erik Jones escribió:
> On Aug 28, 2007, at 4:33 PM, Marko Kreen wrote:
>
>> I've experienced something similar.  The reason turned out to be
>> combination of overcommit=off, big maint_mem and several parallel
>> vacuums for fast-changing tables.  Seems like VACUUM allocates
>> full maint_mem before start, whatever the actual size of the table.
>>
>> Fix was to put "set maint_mem=32M" before small vacuums and
>> serialize some of them.
>
> I'm not sure about the OP but I know that we just run autovacuum so no
> problem with parallel vacuums.  In addition, Solaris doesn't have
> overcommit.

Note that as of 8.3 you will have vacuums running in parallel with
autovac ... 3 in the default config.  So keep an eye on that
maintenance_work_mem setting.

--
Alvaro Herrera                  http://www.amazon.com/gp/registry/5ZYLFMCVHXC
"XML!" Exclaimed C++.  "What are you doing here? You're not a programming
language."
"Tell that to the people who use me," said XML.

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