MySQL Forums
Forum List  »  Optimizer & Parser

Re: Problem with index and left join
Posted by: KimSeong Loh
Date: May 09, 2006 06:17PM

Using a TEXT as a join column?
This is a bad, TEXT can be upto 64KB and the comparison may need to compare upto 64KB, assuming character comparison is 1 operation per character, this is going to take lots of CPU time.

As in why the index is not used, I have no answer.
Maybe it will still su the index on some cases on the 4.1 not it may choose to sacn whole table depends to the value of each row.

Options: ReplyQuote


Subject
Views
Written By
Posted
Re: Problem with index and left join
2440
May 09, 2006 06:17PM
2253
May 09, 2006 11:48PM


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.