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From: Jakub Ouhrabka <kuba@comgate.cz>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
Subject: Re: Linux/PostgreSQL scalability issue - problem with 8 cores
Date: Tue, 15 Jan 2008 13:09:18 +0100
Message-ID: <478CA26E.9040105@comgate.cz> (raw)
In-Reply-To: <13894.1200324134@sss.pgh.pa.us>
References: <flii57$748$1@news.hub.org>
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	<13894.1200324134@sss.pgh.pa.us>

Hi Tom,

 > I can think of three things that might be producing this:

we've found it: TRUNCATE

We'll try to eliminate use of TRUNCATE and the periodical spikes should 
go off. There will still be possibility of spikes because of database 
creation etc - we'll try to handle this by issuing trivial commands from 
idle backeds and in longer run to decrease the number of 
backends/databases running. This is the way to go, right?

One more question: is it ok to do mass regexp update of pg_proc.prosrc 
changing TRUNCATEs to DELETEs? Anything we should be aware of? Sure 
we'll do our own testing but in case you see any obvious downsides...

Many thanks for your guidance!

Kuba



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