On Mon, 30 Aug 2010, Andreas Kretschmer wrote:
Gerhard Wiesinger <lists@xxxxxxxxxxxxx> 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?
The view flattens the key/value structure (for enchanceable technical
measure values) to a flat structure with many columns. The view is that I
have a flat structure and then have easy to write queries for aggregation.
The query itself is just an aggregating query over that flat structure.
Any ideas for better optimizations?
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;
I will try that. But what I don't understand: query was really fast in
8.3 even with 24 hours timeframe.
Assuming you can read a german text:
http://www.pg-forum.de/h-ufig-gestellte-fragen-faq/4067-faq-zeilen-zu-spalten.html
Hopefully yes :-) after that Fedora/Postgresql nightmare update night
(Parallel Fedora upgrade stalled whole machine since that query from
Nagios was executed I guess hundreds of times since it got very slow in
8.4). Machine was pingable but nothing else even on console :-( RAID
rebuild and all other stuff :-(
I planned the upgrade but I didn't expect problems with the query plan
instability :-(
Thnx.
Ciao,
Gerhard
--
http://www.wiesinger.com/
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