MySQL Forums
Forum List  »  Performance

Re: Query problem (update by author)
Posted by: KimSeong Loh
Date: October 22, 2004 04:14PM

Missed that the combined index you refer to is on tableA_ID an dtableB_ID. Sorry about that.
An EXPLAIN may help you discover the problem.
And, the first time the query is executed, the index has to be fetched from the disk, so not much speed up can be achieved.

Looking at your 7 millions rows, the combined index of tableA_ID and tableB_ID will need at least 70MB, you should set you key_buffer_size to be larger than this. It is recommended to set it to about 30% of your memory.

Options: ReplyQuote

Written By
October 22, 2004 07:32AM
October 22, 2004 04:07PM
Re: Query problem (update by author)
October 22, 2004 04:14PM

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.