Re: Database Statistics??? - Mailing list pgsql-performance

From Mario Weilguni
Subject Re: Database Statistics???
Date
Msg-id 200707132019.51450.mweilguni@sime.com
Whole thread Raw
In response to Database Statistics???  (smiley2211 <smiley2211@yahoo.com>)
List pgsql-performance
Am Freitag 13 Juli 2007 schrieb smiley2211:
> Hello all,
>
> I am a bit confused...I have a database which was performing very POORLY
> selecting from a view (posted earlier) on one server but extremely fast on
> another server...
>
> I just backed up the database from the FAST server and loaded to the SLOW
> server and it ran just as fast as it originally did...my questions are:
>
> Are STATISTICS some how saved with the database??  if so, how do I UPDATE
> view or update them?
>
> Should I backup the data \ drop the database and reload it to make it get
> new stats?? (vacuum analyze does nothing for this poor performing database)
>
> Thanks-a-bunch.

Try this on both machines:
select relname, relpages, reltuples
  from pg_class
 where relkind='i'
   order by relpages desc limit 20;

Compare the results, are relpages much higher on the slow machine?

If so, REINDEX DATABASE slow_database;


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