Just added more indexes and found a good one. thanx for the advise ! =) /C ----- Original Message ----- From: "Claus Reestrup" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, November 29, 2002 2:28 PM Subject: Wont use Index when data is not evenly distributed
> Cant figure out why MySQL wont use index on a big table. > Ok, the data is not evenly distributed which might be the problem. > > Look here: > > I have a table with 1 million records, with the following fields: > IdUser, int > X, int > Y, int > Z, int > C, char(10) > > no, varchars, text, or blobs. > > IdUser is a user identity. > As things are right now, only 3 users are registered. > iduser=2, 34, 39 > User 39 owns 99.999 % of the data in the table. > > When using EXPLAIN, Mysql tells me that when querying the table with IdUser=39, >MySQL will not use index. > Querying the table with all other idusers than 39, causes MySQL to use index. > > Has anyone of you seen this behavious before? > > /Claus > > > > > > --------------------------------------------------------------------- > 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 > > > --------------------------------------------------------------------- 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
