MySQL Forums
Forum List  »  Optimizer & Parser

Re: why left join can not use unique index?
Posted by: Rick James
Date: December 15, 2015 11:08AM

An index is a "table" organized based on the declared Collation. Hence, the index is useless when you want to look up something in a different Collation.

In utf8_german2_ci, these are all equal: ae=Ä=Æ=ä=æ
But in utf8_bin, they are scattered around. 'ae' is between 'ad' and 'af'; the others are separately stored separately somewhere after 'z'.

Options: ReplyQuote


Subject
Views
Written By
Posted
2361
h h
December 07, 2015 08:30PM
861
h h
December 11, 2015 03:20AM
Re: why left join can not use unique index?
885
December 15, 2015 11:08AM


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.