>>>>> "Rick" == Rick Moore <lrmoore@stripped> writes:
Rick> I'm seeing the same thing with 3.23.3, but the real odd thing is that CPU
Rick> and disk activity are extremely low. I can't figure out what's taking so
If you could post the query in question, I may be able to comment on this..
Rick> ----- Original Message -----
Rick> From: David Sklar <sklar@stripped>
Rick> To: <mysql@stripped>
Rick> Sent: Monday, September 27, 1999 1:26 PM
Rick> Subject: temp tables in memory vs. disk
>> How can I find out if, for a particular query, MySQL uses tmp tables in
>> or on disk? I get a bunch of queries that sit in 'Copying to tmp table'
>> for too long (but they do finish), and I want to see if I can tune some
>> to speed them up. I am using 3.22.14-gamma.
You can 'easily' check this if you have any temporary files named
SQL-* in /tmp or /var/tmp while you do the query.
MySQL will use in memory tables if the result of the SELECT doesn't
contain BLOB/TEXT columns and you are not using SQL_BIG_TABLES.
Generally, MySQL 3.23 is much faster on GROUP BY and DISTINCT queries