Subject: Re: Large databases, performance
From: Ron Johnson <ron.l.johnson@cox.net>
To: pgsql-performance@postgresql.org
In-Reply-To: <3D9CBAD7.23509.A908C61@localhost>
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	<3D9CBAD7.23509.A908C61@localhost>
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Date: 03 Oct 2002 12:38:49 -0500
Message-Id: <1033666730.28946.64.camel@haggis>
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On Thu, 2002-10-03 at 11:17, Shridhar Daithankar wrote:
> On 3 Oct 2002 at 11:57, Robert Treat wrote:
> 
[snip]
> > I'm curious, did you happen to run the select tests while also running
> > the insert tests? IIRC the older mysql versions have to lock the table
> > when doing the insert, so select performance goes in the dumper in that
> > scenario, perhaps that's not an issue with 3.23.52? 
> 
> IMO even if it locks tables that shouldn't affect select performance. It would 
> be fun to watch when we insert multiple chunks of data and fire queries 
> concurrently. I would be surprised if mysql starts slowing down..

What kind of lock?  Shared lock or exclusive lock?  If SELECT
performance tanked when doing simultaneous INSERTs, then maybe there
were exclusive table locks.

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