Re: FreeSpaceMap hashtable out of memory

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Maksim Likharev" <mlikharev(at)aurigin(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: FreeSpaceMap hashtable out of memory
Date: 2003-10-01 23:24:00
Message-ID: 10658.1065050640@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

"Maksim Likharev" <mlikharev(at)aurigin(dot)com> writes:
> 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

Yeah, the FSM hashtable is in shared memory, so your problem is that
you're running out of shared memory. This is not necessarily the fault
of the FSM as such though; it could be that some other shared data
structure is growing bigger than it was expected to.

Thinking about it, I'm fairly certain that the FSM can't grow larger
than the bounds you set for it, and so the problem is presumably
elsewhere. The most likely bet is that the lock table is getting larger
than expected. There is a control knob for the estimated size of the
lock table (max_locks_per_transaction), so if that's where the problem
is, it's easy to fix. You should try to find out if that's the issue
though. When this happens, are there a very large number of entries in
the pg_locks view?

regards, tom lane

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Jingren Zhou 2003-10-02 00:25:43 PREPARE/EXECUTE across backends?
Previous Message Tom Lane 2003-10-01 23:11:27 Re: Thoughts on maintaining 7.3