MySQL Forums
Forum List  »  Performance

Re: Improving count(distinct) - group by - query
Posted by: KimSeong Loh
Date: February 18, 2005 02:54AM

The query needs to read all the 5 million records.

Maybe a composite index on (tel,telefb) can help a little bit. This allows the index to be used to do the count, so no need to read the data rows.

Options: ReplyQuote

Written By
Re: Improving count(distinct) - group by - query
February 18, 2005 02:54AM

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.