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Re: FreeSpaceMap hashtable out of memory

From: "Maksim Likharev" <mlikharev(at)aurigin(dot)com>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: FreeSpaceMap hashtable out of memory
Date: 2003-10-01 22:50:04
Message-ID: 56510AAEF435D240958D1CE8C6B1770A016D2E1D@mailc03.aurigin.com (view raw or flat)
Thread:
Lists: pgsql-hackers
It is problematic to produce small enough subset, due to large DB and 
randomness of the situation.
But here is what we see in server log file, see below:

It seems like 
WARNING:  ShmemAlloc: out of memory
ERROR:    FreeSpaceMap hashtable out of memory

goes together, does it related to the size of Shared Memory or could
increase of 
Shared Memory solve the thing or that just a coincidence?

Another thing ( from the code) it seems that
hash_search trying to inset new entry into DynHash and cannot allocate
memory
in DynHash Context, so another question is DynHash Context upper
limited, another word
cannot grow more than 8 * 1024 * 1024 byte?

Any suggestions are welcome, 
Thank you.


------------------- LOG
----------------------------------------------------
LOG:  all server processes terminated; reinitializing shared memory and 
semaphores
IpcMemoryCreate: shmget(key=5432001, size=4669440, 03600) failed: Not
enough 
core

This error usually means that PostgreSQL's request for a shared
memory segment exceeded available memory or swap space.
To reduce the request size (currently 4669440 bytes), reduce
PostgreSQL's shared_buffers parameter (currently 256) and/or
its max_connections parameter (currently 128).

The PostgreSQL Administrator's Guide contains more information about
shared memory configuration.


Error 2:
WARNING:  ShmemAlloc: out of memory
ERROR:  FreeSpaceMap hashtable out of memory



-----Original Message-----
From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us]
Sent: Wednesday, October 01, 2003 2:51 PM
To: Maksim Likharev
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: [HACKERS] FreeSpaceMap hashtable out of memory 


"Maksim Likharev" <mlikharev(at)aurigin(dot)com> writes:
> Using PG under Cygwin we having following error message during INSERT
> INTO
> "FreeSpaceMap hashtable out of memory".

Hm, that's not supposed to happen.  Can you create a reproducible
example?

			regards, tom lane

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