From: Ann W. Harrison
Date: December 4 2008 4:26pm
Subject: Re: Please review fox for bug#34479
List-Archive: http://lists.mysql.com/falcon/255
Message-Id: <493804A8.9090304@mysql.com>
MIME-Version: 1.0
Content-Type: text/plain; format=flowed; charset=UTF-8
Content-Transfer-Encoding: 7BIT

Lars,
> 
> Actually there is only one test that fails:
> 
> CREATE TABLE t1 (a char(4) CHARACTER SET utf8 COLLATE utf8_turkish_ci,
> KEY (a));
> INSERT INTO t1 VALUES ('abc'), ('abc '), ('abcd');
> SELECT count(*) FROM t1 WHERE a like 'abc%';
> count(*)
> -3
> +1
> 
> 

That's odd - it does look as if we're requiring that the % sign
match at least one character.  That's wrong.  In the immortal prose
of the SQL standard:


3) If the i-th substring of PCV is an arbitrary string specifier,
then the i-th substring of MCV is any sequence of 0 (zero) or
more characters.

(PCV is the pattern character string, an "arbitrary string specifier"
is a "%" and MCV is the character string being examined.)

This may not be an index problem.

Best,

Ann