Re: Can you spot the difference?

On 04/16/2013 12:07 PM, Moshe Jacobson wrote:
> Hi PostgreSQL friends,
>
> I have two databases in the same cluster that are almost identical. One
> is a copy of the other as we are developing some new features in the copy.
>
> My problem is that the exact same simple query performs great in the
> original database ("ises") and dismally in the copy database
> ("ises_coelacanth"). The problem is that in ises, it uses an index scan,
> but in ises_coelacanth it uses a sequential scan:

The difference is that Postgres is coming to alternate conclusions as to
what plan to use. 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?

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

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com