Re: Can you spot the difference?

On 04/16/2013 01:55 PM, Moshe Jacobson wrote:
> On Tue, Apr 16, 2013 at 3:29 PM, Adrian Klaver <adrian.klaver@gmail.com
> <mailto:adrian.klaver@gmail.com>> wrote:
>
>     Given that the copy is causing the 'problem', the question to ask
>     is; did you run ANALYZE on the table once the data was copied in?
>
>
> I did not -- I expected the autovacuum daemon to do so. Why did it not?
> The database was created & restored days ago, and the autovacuum daemon
> is running with default settings.

http://www.postgresql.org/docs/9.2/static/routine-vacuuming.html

"
The autovacuum daemon, if enabled, will automatically issue ANALYZE
commands whenever the content of a table has changed sufficiently.
However, administrators might prefer to rely on manually-scheduled
ANALYZE operations, particularly if it is known that update activity on
a table will not affect the statistics of "interesting" columns. The
daemon schedules ANALYZE strictly as a function of the number of rows
inserted or updated; it has no knowledge of whether that will lead to
meaningful statistical changes.
"

So at a guess there has not been enough churn on the table.

>
> Thanks.
>
> --
> Moshe Jacobson
> Nead Werx, Inc. | Manager of Systems Engineering
> 2323 Cumberland Parkway, Suite 201 | Atlanta, GA 30339
> moshe@neadwerx.com <mailto:moshe@neadwerx.com> | www.neadwerx.com
> <http://www.neadwerx.com/>
>
> "Quality is not an act, it is a habit." -- Aristotle


--
Adrian Klaver
adrian.klaver@gmail.com