Re: Memory usage after upgrade to 9.2.4 - Mailing list pgsql-general

From Daniel Cristian Cruz
Subject Re: Memory usage after upgrade to 9.2.4
Date
Msg-id CACffM9GVxyu6zw9ZY7RJPN7Lks4mt8hywZ1fwtnx80YmK4bqfA@mail.gmail.com
Whole thread Raw
In response to Re: Memory usage after upgrade to 9.2.4  (Adrian Klaver <adrian.klaver@gmail.com>)
Responses Re: Memory usage after upgrade to 9.2.4
List pgsql-general



2013/4/21 Adrian Klaver <adrian.klaver@gmail.com>
On 04/21/2013 07:50 AM, Daniel Cristian Cruz wrote:



2013/4/21 Adrian Klaver <adrian.klaver@gmail.com
<mailto:adrian.klaver@gmail.com>>


    On 04/21/2013 06:37 AM, Daniel Cristian Cruz wrote:

        2013/4/21 Tom Lane <tgl@sss.pgh.pa.us <mailto:tgl@sss.pgh.pa.us>
        <mailto:tgl@sss.pgh.pa.us <mailto:tgl@sss.pgh.pa.us>>>



             Tomas Vondra <tv@fuzzy.cz <mailto:tv@fuzzy.cz>
        <mailto:tv@fuzzy.cz <mailto:tv@fuzzy.cz>>> writes:
              > I do have a log with the memory context info printed
        after the OOM
              > killed the session - see it attached.

             The only thing that seems rather bloated is the
        CacheMemoryContext,
             which seems to be because the backend has cached info about
        several
             thousand tables and indexes.  Given that you say there's
        9500 relations
             in their schema, it's hard to believe that 9.2.4 is
        suddenly doing that
             where 9.2.3 didn't.  I'm wondering if they've done
        something else that
             restricted the amount of memory available to a backend.


        Maybe, since I'm running the same server and top shows a RES
        size a bit
        large for idle sessions. Not so large than 9.2. Bellow is the actual
        server top.


    Just to be clear the below is for the 9.1.4 server you rolled backed to?


Yes.

To recap for those following along, there are two different cases in play here.

1)
Major upgrade from 9.1.4 to 9.2.4.
Used pg_upgrade
Tested on VM with 9.2.4 and no problems.
Same machine used for production server 9.1.4 and 9.2.4
When complex queries where run on production server under 9.2.4 memory usage climbed out of control.

Unanswered questions:

a) Data set sizes between test and production machines, how do they differ?

It's the same on both; we do a dump/restore every day to the development / issue team work.
 

b) What are the EXPLAIN/ANALYZE results for a query on 9.1.4, 9.2.4 test and 9.2.4 production?

Since there is no single query causing  the problem, I don't know if it could help.
 
One thing I didn't mention: I build a record table used to track every transaction on database, and all tables are inherited from it. This way I easily found the records to transfer from 9.2.4 to 9.1.x.

But it's something similar with the other case, where they are using for partitioning purposes, and I'm using to simplify the model (the inherited table is hidden in the model).

Thanks,
--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

pgsql-general by date:

Previous
From: Adrian Klaver
Date:
Subject: Re: Memory usage after upgrade to 9.2.4
Next
From: Daniel Cristian Cruz
Date:
Subject: Fwd: Memory usage after upgrade to 9.2.4