"Dmitry E. Oboukhov" <unera(at)debian(dot)org> writes:
> Recently I started a hard query (ALTER TABLE) and then Postgresql was
> killed by OOM killer.
> ...
> 2012-04-15 16:46:02 MSK LOG: server process (PID 825) was terminated by signal 11: Segmentation fault
You sure it was an OOM kill? The OOM killer does its dirty work with
signal 9 (SIGKILL), not signal 11 (SIGSEGV).
regards, tom lane