Re: getting our bearings on "out of memory. failed on request of size..."

Thanks Tom,

   The "n" has always been small, like 20, or 4 or 32 (these numbers
are from memory, not written down), but the one we ran into today was
large: 67108864.

   I will head to the EXPLAIN, as well as to getting the memory dump
from the log.

Regards,
-Tom

------------------------------------------------------------
Tom Darci
tom@nuws.com

On Oct 28, 2008, at 7:44 AM, Tom Lane wrote:

> Tom Darci <tom@nuws.com> writes:
>>   Our PG server is serving up 50 databases or so (with identical
>> schemas), and the largest one of those has started giving us "out of
>> memory. failed on request of size n" errors in many places. This is a
>> 9 GB database with 100+ tables, the largest of which have 4 million
>> or
>> so rows. We see the Out of Memory errors when trying to run a "hard"
>> SQL statement (SELECTing from a complex view, updating all rows in a
>> large table, etc...)
>
> Well, it would be important to know if "n" is little or big, and to
> see
> the EXPLAIN output of the problem query.  Also, an out-of-memory error
> will cause a memory usage map to be dumped to postmaster stderr ---
> that would be pretty useful to see too, if your logging setup captures
> it.
>
>             regards, tom lane