Re: Seg fault in postgres 7.4.7?

Akash Garg wrote:
> My postgres 7.4.7 installation crashed on its own today -- here is the
> error log:
>
> ERROR:  duplicate key violates unique constraint "toolbar_pkey"
> LOG:  server process (PID 22753) was terminated by signal 11
> LOG:  terminating any other active server processes
> WARNING:  terminating connection because of crash of another server process
> DETAIL:  The postmaster has commanded this server process to roll back
> the current transaction and exit, because another server process
> exited abnormally and possibly corrupted shared memory.
>
> Is this a known bug?

Well - a sig-11 (segment violation/fault) is generally caused by
dereferencing a pointer that is corrupted. So, it could be:
  1. Hardware fault
  2. Data corruption (of the index, caused by a previous crash)
  3. Programming error.

It's probably worth running one of the "memtest" tools to check you
don't have a fault with your RAM chips. It could also be a fault in your
disk controller/drives, but that's harder to test for (unless you're
seeing disk errors).

Before that though, make sure your backups are good (it doesn't hurt to
be over-cautious). Re-index (see REINDEX command in manuals) the index
in question, that can't hurt either if you've had a power-failure or
similar in the past.

OK - if you've ruled out memory problems and not had a crash then it
might be a bug in 7.4.7. I've searched the "bugs" mailing list for the
last 6 months at http://archives.postgresql.org/

Can't see anything there, so if it's a bug in the 7.4 series, you're the
first to discover it. There might be something unusual about your
installation. Can you give details (did you install from source/package,
what OS, what OS version, character set, locale, any patches/add-on
modules).

--
   Richard Huxton
   Archonet Ltd