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@xxxxxxxxxxxx]
Sent: Thursday, April 20, 2006 12:49 PM
To: Doron Baranes; pgsql-performance@xxxxxxxxxxxxxx
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
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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
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TIP 2: Don't 'kill -9' the postmaster
