Re: Warning when selecting column from pg_stat_user_tables.

Chris Barnes wrote:
>
> I have this error when selecting from the pg_stat_user_tables. I
> restarted postgres and the error went away.
> Has anyone else seen this error?
> [postgres@preventdb02 londiste]$ cat
> /data/pgsql/data/pg_log/postgresql-Tue.log
> WARNING:  pgstat wait timeout

There have been periodic reports of these wait timeouts messing with the
statistics results returned by the database for a while now; some examples:

http://archives.postgresql.org/pgsql-bugs/2009-07/msg00081.php
http://archives.postgresql.org/pgsql-bugs/2009-12/msg00175.php

I just ran into one of the myself recently, wasn't able to reproduce
though.  There seems to be something subtle going wrong in statistics
collection, nobody seems exactly sure what it is yet though.

I wouldn't get stressed about it unless these become frequent, in which
case we'd probably want to ask you to collect more data about your
system to try and catch more information about one of them when it shows up.

--
Greg Smith    2ndQuadrant   Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com  www.2ndQuadrant.com