Re: Major performance problem after upgrade from 8.3 to 8.4 - Mailing list pgsql-performance

From Andreas Kretschmer
Subject Re: Major performance problem after upgrade from 8.3 to 8.4
Date
Msg-id 20100830072230.GA28373@tux
Whole thread Raw
In response to Major performance problem after upgrade from 8.3 to 8.4  (Gerhard Wiesinger <lists@wiesinger.com>)
Responses Re: Major performance problem after upgrade from 8.3 to 8.4  (Pavel Stehule <pavel.stehule@gmail.com>)
Re: Major performance problem after upgrade from 8.3 to 8.4  (Gerhard Wiesinger <lists@wiesinger.com>)
List pgsql-performance
Gerhard Wiesinger <lists@wiesinger.com> wrote:

> I know that the data model is key/value pairs but it worked well in 8.3.
> I need this flexibility.
>
> Any ideas?

If i understand the query correctly it's a pivot-table, right?

If yes, and if i where you, i would try to rewrite this query, to
something like:

select
  timestamp,
  sum (case when keyid = 1 then value else 0 end) as Raumsolltemperatur,
  ...
from
  log
group by
  timestamp;


Assuming you can read a german text:
http://www.pg-forum.de/h-ufig-gestellte-fragen-faq/4067-faq-zeilen-zu-spalten.html



Andreas
--
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unintentional side effect.                              (Linus Torvalds)
"If I was god, I would recompile penguin with --enable-fly."   (unknown)
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