Re: PQgetCopyData() failed - corruption?

Le 2013-04-18 à 16:02, Tom Lane a écrit :

> =?iso-8859-1?Q?Fran=E7ois_Beausoleil?= <francois(at)teksol(dot)info> writes:
>> I received the following error while backing up my database:
>
>> pg_dump: Dumping the contents of table "summary_show_unique_personas_2012_10_15" failed: PQgetCopyData() failed.
>> pg_dump: Error message from server: pg_dump: The command was: COPY public.summary_show_unique_personas_2012_10_15 (market_id, period, show_id, service_id, service_name, gender, followers_count, interactions_count) TO stdout;
>
> Hmm, what libpq version is pg_dump depending on? The lack of any "error
> message from server" (which in this case really means "from libpq") is
> odd. AFAICS, it is impossible in the current code for PQgetCopyData to
> return a failure indication without setting up an appropriate textual
> message too --- but it sure looks like it did for you, so I'm wondering
> if this is an old version with some bug in the error handling code paths.

Most recent version, as far as I can tell.

# ldd /usr/lib/postgresql/9.1/bin/pg_dump | grep pq
libpq.so.5 => /usr/lib/libpq.so.5 (0x00007ff315dcd000)
# pg_dump --version
pg_dump (PostgreSQL) 9.1.9

This is a Ubuntu 12.04, and no packages are outdated on the system that calls pg_dump. The server is 9.1.8, and is planned to upgrade this week. Yes, my firewall is up and protecting me.

>> Does that error indicate a database corruption? Or just a network interruption?
>
> I'd guess it's just a lost connection. You could look at the
> postmaster's log to see what happened according to that end.
> If it logged "unexpected EOF on client connection" or some such, then
> it was indeed just a dropped connection.

I have a few around that time, but that message appears every few seconds outside the dropped connection window. If the connection is torn down correctly, that message should not appear, right?

Anyways, looks more like a random network disconnect, since the dump that I started on the database server itself is still progressing nicely and does not appear to have problems.

Thanks for checking this out,
François Beausoleil