Re: Performance issue 6.5 versus 7.0 - Mailing list pgsql-general

From Herbert Liechti
Subject Re: Performance issue 6.5 versus 7.0
Date
Msg-id 392EE288.F11EBC8D@thinx.ch
Whole thread Raw
In response to Performance issue 6.5 versus 7.0  (Herbert Liechti <Herbert.Liechti@thinx.ch>)
Responses Re: Performance issue 6.5 versus 7.0
List pgsql-general
Bryan White wrote:
>
> > Is there a way to force 7.0 using the defined indexes? Thanks
> > for your help.
>
> Try set enable_seqscan=off before issuing your query.

A little bit better (3 sec instead of 5 seconds). But fare away
from the performance of 6.5.3. The explain now looks like this:

EXPLAIN
SELECT MailingListe_Id, MailingStatus, AbschlussDatum, Anschrift.Anzeige,
       Anschrift.Postfach, Anschrift.Strasse, Anschrift.Plz, Anschrift.Ort,
       Anschrift.TelDirekt, Person.Person_Id, Person.Name, Person.Vorname,
       Person.Anzeige
  FROM Anschrift, Person, MailingListe
 WHERE Person.Person_Id = MailingListe.Person_Id
   AND Anschrift.Anschrift_Id = MailingListe.Anschrift_Id
   AND MailingListe_Id = 2104;

NOTICE:  QUERY PLAN:
Merge Join  (cost=3717.38..7842.55 rows=1988449 width=136)
  ->  Sort  (cost=3717.38..3717.38 rows=8268 width=96)
        ->  Merge Join  (cost=44.73..2941.79 rows=8268 width=96)
              ->  Index Scan using anschrift_id_ix on anschrift  (cost=0.00..2725.55 rows=13661 width=76)
              ->  Sort  (cost=44.73..44.73 rows=61 width=20)
                    ->  Index Scan using mailingliste_id_ix on mailingliste  (cost=0.00..42.94 rows=61 width=20)
  ->  Index Scan using person_id_ix on person  (cost=0.00..3721.19 rows=24051 width=40)


An other advice?
Herbie
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Herbert Liechti                     E-Mail: Herbert.Liechti@thinx.ch
ThinX networked business services        Stahlrain 10, CH-5200 Brugg
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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