Re: Perfrmance Problems (7.4.6)
От | Ruben Rubio Rey |
---|---|
Тема | Re: Perfrmance Problems (7.4.6) |
Дата | |
Msg-id | 4447A09D.9070600@rentalia.com обсуждение исходный текст |
Ответ на | Re: Perfrmance Problems (7.4.6) ("Doron Baranes" <doron.baranes@dbnet.co.il>) |
Список | pgsql-performance |
Did you tried to index the expression? Did it work? Doron Baranes wrote: >Ok. But that means I need a trigger on the original column to update the >new column on each insert/update and that overhead. > >-----Original Message----- >From: Ruben Rubio Rey [mailto:ruben@rentalia.com] >Sent: Thursday, April 20, 2006 12:49 PM >To: Doron Baranes; pgsql-performance@postgresql.org >Subject: Re: [PERFORM] Perfrmance Problems (7.4.6) > >I think that the problem is the GROUP BY (datetime) that is >date_trunc('hour'::text, i.entry_time) >You should create an indexe with this expression (if its possible). > >http://www.postgresql.org/docs/7.4/interactive/indexes-expressional.html > >If is not possible, I would create a column with value >date_trunc('hour'::text, i.entry_time) of each row and then index it. > >Hope this helps :) > >Doron Baranes wrote: > > > >>Hi, >> >>I am running on postgres 7.4.6. >>I did a vacuum analyze on the database but there was no change. >>I Attached here a file with details about the tables, the queries and >>the Explain analyze plans. >>Hope this can be helpful to analyze my problem >> >>10x >>Doron >> >> >>----------------------------------------------------------------------- >> >> >- > > >>---------------------------(end of >> >> >broadcast)--------------------------- > > >>TIP 9: In versions below 8.0, the planner will ignore your desire to >> choose an index scan if your joining column's datatypes do not >> match >> >> >> >> > > >---------------------------(end of broadcast)--------------------------- >TIP 2: Don't 'kill -9' the postmaster > > > >
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