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From:Martin Gainty Date:September 26 2008 12:11am
Subject:RE: Help!
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2 items
I would increase bump key_buffer_size as suggested here
http://dev.mysql.com/doc/refman/5.1/en/delete-speed.html

also TRUNCATE instead of DELETE where TRANSACTION is not active

Martin 
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> Date: Thu, 25 Sep 2008 15:45:00 -0700
> From: andrewmchorney@stripped
> To: gpeel@stripped; mysql@stripped
> Subject: Re: Help!
> 
> Hello
> 
> I would not recommend delete massive numbers of records in a single sql statement. I
> have had problems doing this on a system with few records (1.7 million) and doing a delete
> with a condition clause of "where 1 = 1".  The server had problems with this. 
> 
> The MySQL server is probably building some rollback code in case something goes
> wrong. If it succeeds it will be a good amount of time. I would recommend doing several
> small deletes.
> 
> Andrew
> 
> 
> 
> ---- Grant Peel <gpeel@stripped> wrote: 
> > Hi all,
> > 
> > I have a table I needed to prune because it had grown to 5 million rows and
> > it appeared that that app that uses it couldnt anymore.
> > 
> > I am in the process of:
> > 
> > DELETE FROM mytable WHERE id < 3000000;
> > 
> > the above has been running for close than an hour and I am starting to get a
> > little nervous.
> > 
> > it is on freebsd 6.3, mysql 4.x on a Single core dell 2.8 GHx I think.
> > 
> > I have shut down all process but necessary one so mysql has full access to
> > the cpu.
> > 
> > Should I be worried? Is there anything I can do to speed this up?
> > 
> > -G
> > 
> > 
> > 
> > -- 
> > MySQL General Mailing List
> > For list archives: http://lists.mysql.com/mysql
> > To unsubscribe:    http://lists.mysql.com/mysql?unsub=1
> > 
> 
> 
> -- 
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:    http://lists.mysql.com/mysql?unsub=1
> 

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Thread
Help!Grant Peel26 Sep
  • Re: Help!andrewmchorney26 Sep
    • RE: Help!Martin Gainty26 Sep
      • Re: Help!Ananda Kumar26 Sep