MySQL Forums
Forum List  »  Optimizer & Parser

Why not use index
Posted by: zhang peng
Date: November 08, 2015 11:14PM

I write follow sql:
select * from A t1 left join B t2 on t1.mid=t2.id or t1.sid=t2.id

mid is primary key of A,both sid and id have index, but why mysql not use index

Options: ReplyQuote


Subject
Views
Written By
Posted
Why not use index
1687
November 08, 2015 11:14PM
855
November 09, 2015 11:42AM
864
November 11, 2015 12:17AM
896
November 10, 2015 10:35AM
1050
November 11, 2015 12:15AM
938
November 11, 2015 03:40AM
1190
November 11, 2015 07:29PM
832
November 11, 2015 11:00PM
928
November 12, 2015 01:48AM
895
November 16, 2015 12:17AM


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.