SQL 'LIKE BINARY' any slower than plain 'LIKE'?

Question

I\'m using a django application which does some \'startswith\' ORM operations comparing longtext columns with a unicode string. This results in a LIKE BI

Answer 1

For the next person who runs across this - in our relatively small database the query:

SELECT * FROM table_name WHERE field LIKE 'some-field-search-value';

... Result row

Returns 1 row in set (0.00 sec)

Compared to:

SELECT * FROM table_name WHERE field LIKE BINARY 'some-field-search-value';

... Result row

Returns 1 row in set (0.32 sec)

Long story short, at least for our database (MySQL 5.5 / InnoDB) there is a very significant difference in performance between the two lookups.

Apparently though this is a bug in MySQL 5.5: http://bugs.mysql.com/bug.php?id=63563 and in my testing against the same database in MySQL 5.1 the LIKE BINARY query still uses the index (while in 5.5 it does a full table scan.)