Re: Oracle v. Postgres 9.0 query performance

pg_dw=# show random_page_cost ;
 random_page_cost
------------------
 4
(1 row)

Time: 0.299 ms
pg_dw=# show seq_page_cost ;
 seq_page_cost
---------------
 1
(1 row)

Time: 0.250 ms
pg_dw=# show work_mem ;
 work_mem
----------
 768MB
(1 row)




On Wed, 2011-06-08 at 18:27 +0200, Pavel Stehule wrote:
> Hello
>
> what is your settings for
>
> random_page_cost, seq_page_cost and work_mem?
>
> Regards
>
> Pavel Stehule
>
> 2011/6/8 Tony Capobianco <tcapobianco@prospectiv.com>:
> > Here's the explain analyze:
> >
> > pg_dw=# explain analyze CREATE TABLE ecr_opens with (FILLFACTOR=100)
> > as
> > select o.emailcampaignid, count(memberid) opencnt
> >  from openactivity o,ecr_sents s
> >  where s.emailcampaignid = o.emailcampaignid
> >  group by o.emailcampaignid;
> >
> > QUERY
> > PLAN
> >
----------------------------------------------------------------------------------------------------------------------------------------------------------------
> >  GroupAggregate  (cost=0.00..1788988.05 rows=9939 width=12) (actual
> > time=308630.967..2592279.526 rows=472 loops=1)
> >   ->  Nested Loop  (cost=0.00..1742467.24 rows=9279316 width=12)
> > (actual time=31.489..2589363.047 rows=8586466 loops=1)
> >         ->  Index Scan using ecr_sents_ecid_idx on ecr_sents s
> > (cost=0.00..38.59 rows=479 width=4) (actual time=0.010..13.326 rows=479
> > loops=1)
> >         ->  Index Scan using openact_emcamp_idx on openactivity o
> > (cost=0.00..3395.49 rows=19372 width=12) (actual time=1.336..5397.139
> > rows=17926 loops=479)
> >               Index Cond: (o.emailcampaignid = s.emailcampaignid)
> >  Total runtime: 2592284.336 ms
> >
> >
> > On Wed, 2011-06-08 at 17:31 +0200, tv@fuzzy.cz wrote:
> >> > On Postgres, this same query takes about 58 minutes (could not run
> >> > explain analyze because it is in progress):
> >> >
> >> > pg_dw=# explain CREATE TABLE ecr_opens with (FILLFACTOR=100)
> >> > pg_dw-# as
> >> > pg_dw-# select o.emailcampaignid, count(memberid) opencnt
> >> > pg_dw-#   from openactivity o,ecr_sents s
> >> > pg_dw-#  where s.emailcampaignid = o.emailcampaignid
> >> > pg_dw-#  group by o.emailcampaignid;
> >> >                                                  QUERY
> >> > PLAN
> >> > -------------------------------------------------------------------------------------------------------------
> >> >  GroupAggregate  (cost=0.00..1788988.05 rows=9939 width=12)
> >> >    ->  Nested Loop  (cost=0.00..1742467.24 rows=9279316 width=12)
> >> >          ->  Index Scan using ecr_sents_ecid_idx on ecr_sents s
> >> > (cost=0.00..38.59 rows=479 width=4)
> >> >          ->  Index Scan using openact_emcamp_idx on openactivity o
> >> > (cost=0.00..3395.49 rows=19372 width=12)
> >> >                Index Cond: (o.emailcampaignid = s.emailcampaignid)
> >> > (5 rows)
> >> >
> >>
> >> Please, post EXPLAIN ANALYZE, not just EXPLAIN. Preferably using
> >> explain.depesz.com.
> >>
> >> regards
> >> Tomas
> >>
> >>
> >
> >
> >
> > --
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>