Re: Database corruption in RH 6.2/prepackaged PG

pgsql-bugs@postgresql.org writes:
> Problem description:
> The nightly cron jobs return me the following message:
> ----
> dumpClasses(): command failed.  Explanation from backend: 'pqReadData() -- backend closed the channel unexpectedly.
>         This probably means the backend terminated abnormally
>         before or while processing the request.

Can't tell much from this.  What would be useful is to look at the
postmaster log and a stack backtrace from the crashed backend.

The default startup script for your RH probably sends the postmaster
log file to the bit-bucket, so you'll have to change it.  Make sure
the postmaster is invoked without -S switch, and redirect its stdout
and stderr to some handy log file, etc

    postmaster -i -D wherever >/full/path/to/logfile 2>&1 &

(The extra & at the end is needed if you don't use -S.)

If you don't see a core file in $PGDATA/base/yourdb/core, then you
probably also need to add "ulimit -c unlimited" to the postmaster
start script, to allow dumping core from the postmaster and its
child processes.

Let us know when you have more detail ...

            regards, tom lane

PS: BTW, it would probably save time all around if you first update
to Postgres 7.0.3 and then see if the bug is still there.