At 04:47 PM 11/11/2002 +0800, Thomas Seifert wrote: >Are you using MySQL-3.23.x? >AFAIK it doesn't use a key for ORDER BY (MySQL-4.x does). >Maybe thats the cause? >
Hi, Yes. Im using 3.23.52(nt). I just upgraded it from 3.23.27. You mean, if I have ORDER BY as part of the query statement, MySQL doesnot use index/keys? Does this mean, that there is absolutely no way to improve my query? Hmm.. I read lots of good stuffs with MySQL 4.x; is this already safe to use? regards, jaime > >Thomas > >On Mon, 11 Nov 2002 16:41:50 +0800 Jaime Teng <[EMAIL PROTECTED]> wrote: > >> Hi, >> >> I have a mysql table: >> >> mysql> describe eventlog; >> +-------------+------------------+ >> | Field | Type | >> +-------------+------------------+ >> | id | int(10) unsigned | >> | time | datetime | >> | source | varchar(10) | >> | description | varchar(255) | >> +-------------+------------------+ >> >> id is a unique auto_increment key. the way data is entered, this >> key is always sorted. and most importantly, it is a KEY index too. >> >> Currently, this table has about 400,000 entries occupying about >> 30MB of hard disk space. >> >> Whenever I try to perform: >> "SELECT * FROM eventlog where id < number ORDER BY id DESC limit 20;" >> >> The result is very slow, taking 5~10 seconds WHEN number is almost >> at the very top of the list: >> example, >> if max(id) is 3000000, then doing the above search with number being >> 2999990, will be very slow. the performance ONLY increases when >> number is very low OR when >> "select count(*) from eventlog where id < number;" would give a >> small number. >> >> Is there a way to increase the performance of my table/search? >> >> >> jaime >> >> >> >> >> >> --------------------------------------------------------------------- >> 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 > >. > > --------------------------------------------------------------------- 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
