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List:       mysql
Subject:    RE: Help!
From:       Martin Gainty <mgainty () hotmail ! com>
Date:       2008-09-26 0:11:01
Message-ID: BLU142-W32410AB75A0122B13879BEAE470 () phx ! gbl
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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@cox.net
> To: gpeel@ody.ca; mysql@lists.mysql.com
> 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@ody.ca> 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=andrewmchorney@cox.net
> > 
> 
> 
> -- 
> MySQL General Mailing List
> For list archives: http://lists.mysql.com/mysql
> To unsubscribe:    http://lists.mysql.com/mysql?unsub=mgainty@hotmail.com
> 

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