Re: OOM on large SELECT

the output of show work_mem; is:

> Subject: Re: [JDBC] OOM on large SELECT
> From: hannu@2ndQuadrant.com
> To: amenuor@hotmail.com
> CC: pgsql-jdbc@postgresql.org
> Date: Sun, 20 Sep 2009 13:08:23 +0300
>
> On Thu, 2009-09-17 at 19:03 +0200, Angelo Nicolosi wrote:
> > Sorry for the delay of this answer but i was trying to figure out.
> > However I saw that the memory that the postgres is using is getting
> > larger step by step.
> > So it doesn't free it.
>
> If the memory is allocated using palloc() and not freed even after the
> query finishes, then you must be using a wrong memory context.
>
> > After the third query it is already full and one of the thread of the
> > postgres is killed from the OOM.
> > When the process is killed the program usually is going to call again
> > a stored function.
> > By the way the info that you required me are:
> >
> >
> > postgres (PostgreSQL) 8.4.0
> > Linux kernel 2.6.18 64bits
> >
> >
> > For the memory settings I have to contact the system admin because i
> > don't have the rights, on that machines, to read the configurations
> > file.
>
> do
>
> show work_mem;
>
> from psql;
>
> to see all conf params, do
>
> show all;
>
>
>
> > Thank you again to all for your help.
> > Cheers,
> > Angelo.
> >
> > > Date: Wed, 16 Sep 2009 09:30:59 -0700
> > > From: pierce@hogranch.com
> > > To: amenuor@hotmail.com
> > > CC: pgsql-jdbc@postgresql.org
> > > Subject: Re: [JDBC] OOM on large SELECT
> > >
> > > Angelo Nicolosi wrote:
> > > > It's possible that the problem is in my C code but every time that
> > I'm
> > > > allocating memory, using always the palloc() function, I'm always
> > > > calling the pfree().
> > > > There is some way to analyze the code meanwhile is working inside
> > the
> > > > Postgre server (something like valgrind)?
> > > > However the command free -m on my machine outputs:
> > > >
> > > > total used free shared buffers cached
> > > > Mem: 2010 664 1345 0 157 383
> > > > -/+ buffers/cache: 123 1886
> > > > Swap: 16386 41 16345
> > > >
> > > > I think that the swap is enough.
> > > > Could you give me some tips about how can I see where is the
> > problem?
> > > > Thank you for your help!
> > >
> > > do you know what query you were making when you ran out of memory?
> > it
> > > -appears- it was a postgres server process that was OOM'd.
> > >
> > > what OS and version are you on (OOM seems to imply its likely
> > linux,
> > > since no other OS I'm familiar with would randomly kill processes
> > like
> > > that), what version postgres, etc ?
> > >
> > > also, what are the various memory settings in your postgresql.conf
> > > (shared_buffers, work_mem, etc)
> > >
> > >
> >
> >
> >
> > ______________________________________________________________________
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> --
> Hannu Krosing http://www.2ndQuadrant.com
> PostgreSQL Scalability and Availability
> Services, Consulting and Training
>
>