MySQL Forums
Forum List  »  Performance

Re: Help needed on tuning query with join
Posted by: Mike Hillyer
Date: October 12, 2004 03:53PM

Why are you performing a LEFT JOIN? This can slow things up, what INDEXes do you have on the tables?

What does this produce?

EXPLAIN select a.id,a.lookup_data,b.source_id,b.criteria from weblogs as a, left join links as b on a.id=b.source_id where b.criteria=criteria

Mike Hillyer, Technical Writer
MySQL AB, www.mysql.com
Office: +1 403-380-6535

Blog: http://www.openwin.org/mike

"The Open Source movement has become a major force across the software industry, and MySQL is the world's most popular open source database."
--Fortune Magazine

Options: ReplyQuote


Subject
Views
Written By
Posted
6585
October 12, 2004 02:42PM
Re: Help needed on tuning query with join
3371
October 12, 2004 03:53PM


Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.