From: Michael Widenius Date: March 30 1999 8:51pm Subject: Big select filling file system List-Archive: http://lists.mysql.com/mysql/1204 Message-Id: <14081.14057.699617.948213@monty.pp.sci.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit >>>>> "Eric" == Eric D Patterson writes: Eric> I am attempting to run this query on a table consisting of 2M rows: Eric> SELECT DISTINCT part_no,MDealer,Dealer,Model,Orig_Part from parts; Eric> I know it's going to be nasty on the server, but really want to do it Eric> anyway, and run into the following problem: Eric> Mysql is dumping 300+Mb of data to my root partition, filling it, and Eric> causing problems from there on, and I have not been able to find exactly Eric> where these files are, or what they contain. (though i assume they are Eric> temp files getting dumped there for some reason) Eric> Server specs: Eric> runnig mysq 3.22.16a-gamma Eric> DEC alpha (in case it matters) Eric> DEC UNIX Eric> / partition is 500Mb, with ~300Mb free Eric> 512Mb ram, normally 86% free Eric> Does anybody know what these files are, or more importantly, how to make Eric> it not do this? Eric> --If so, please drop me an email at: slacker@stripped Fix: Start mysqld with --tmpdir=path-to-another-partition or Increase the mysqld sort_buffer; This will make MySQL use less temporary place! To execute the above select, MySQL will need temporary space to store 2 copies of the data for: part_no,MDealer,Dealer,Model,Orig_Part,'longint' Regards, Monty