On Tue, Jan 07, 2003 at 11:49:05AM +0100, David Bordas wrote: > > Anybody else who has any idea why the index are not used as they should? > > I've got same things with 3.23.xx and select query through a TCP/IP > connection. > I don't know why, but you can solve this issue using the USE INDEX syntax > for select queries ... > > http://www.mysql.com/doc/en/SELECT.html
Hmmm, that does help. It does not use the filesort anymore. I cannot use the 'use index' hardcoed in this query (is is not always the fastest). I think the following is happening: A select with only constants and an 'order by' does not use the index for the orderby if there are 2 indexes which differ only in that the last one has the 'order by' column append to it. For example: select * from foo where a="const" order by b; indexes: first_index (a), second_index (a,b) The fix should be easy, drop the first_index (It is useless anyway) I'll test this hypothesis tonight when I can do the 20 minute taking alter table :) Thanks, Harmen > > > David > > > --------------------------------------------------------------------- > Before posting, please check: > http://www.mysql.com/manual.php (the manual) > http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > -- The Moon is Waxing Crescent (22% of Full) nieuw.nl - 2dehands.nl: 58501 --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
