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Re: Too slow querying a table of 15 million records

From: PFC <lists(at)boutiquenumerique(dot)com>
To: kjelle(at)bingon(dot)no, pgsql-performance(at)postgresql(dot)org
Subject: Re: Too slow querying a table of 15 million records
Date: 2005-06-28 17:10:05
Message-ID: op.ss3ba3loth1vuj@localhost (view raw or flat)
Thread:
Lists: pgsql-performance

> database=> explain select date_trunc('hour', time),count(*) as total from
> test where p1=53 and time > now() - interval '24 hours' group by
> date_trunc order by date_trunc ;

	1. Use CURRENT_TIMESTAMP (which is considered a constant by the planner)  
instead of now()
	2. Create a multicolumn index on (p1,time) or (time,p1) whichever works  
better

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Next:From: Karl O. PincDate: 2005-06-28 17:16:41
Subject: Re: Poor index choice -- multiple indexes of the same
Previous:From: John A MeinelDate: 2005-06-28 17:02:55
Subject: Re: read block size

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