Bonjour Jean-françois, Le DESC qui utilise l'INDEX est un fonction de MySQL 4.0. Il y a un bug en la version 4.0.1 (Quelque fois il n'utilise pas l'index descendre ) mais pour la plus part ça marche bien. En autre il y a un forum de MySQL en français à: Liens utils : Poster un message: [EMAIL PROTECTED] S'abonner: [EMAIL PROTECTED] Se désabonner : [EMAIL PROTECTED] Ecrire au proprio : [EMAIL PROTECTED]
URL sur Onelist : http://www.onelist.com/community/mysql-france Bonne chance, Amicalement, Ken ----- Original Message ----- From: "Jean-Francois Dionne" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, February 14, 2002 7:25 PM Subject: Need help about mysql order and index.... > Hi there, I hope someone will can help me... First, sorry for bad english :) > i'm french > First all I have those index in my table > +-------+-------------------+-----------------+--------------------+-- ------ > --------------+-------------+----------------+--------------+------- -----+-- > ------------+ > | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | > Cardinality | Sub_part | Packed | Comment | > +-------+-------------------+-----------------+--------------------+-- ------ > --------------+-------------+----------------+--------------+------- -----+-- > ------------+ > | Stats | 0 | PRIMARY | 1 | ID > | A | 4568748 | NULL | NULL | | > | Stats | 1 | Port_ID | 1 | Port_ID > | A | 1 | NULL | NULL | | > | Stats | 1 | Timestamp | 1 | Timestamp > | A | 49126 | NULL | NULL | | > +-------+-------------------+-----------------+--------------------+-- ------ > --------------+-------------+----------------+--------------+------- -----+-- > ------------+ > > You have to know I have 4 500 000 in my db > > Okay I have this query: > select Timestamp from Stats use index (Timestamp) where Timestamp >= > '2002-01-01' and Timestamp < '2002-02-01' order by Timestamp limit 1; > this one is jsut doing fine.. it take 0.00 sec to do it... > > but > select Timestamp from Stats use index (Timestamp) where Timestamp >= > '2002-01-01' and Timestamp < '2002-02-01' order by Timestamp desc limit 1; > this one take sometime 10 sec to do.... I understand is the desc the prob.. > because my index is in asc (collation=A) > my question is... is there a way for maiking a index in desc? or maybe > something else? > > Jean-Francois Dionne > Yard > > > -------------------------------------------------------------------- - > 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
