From: forbbs forbbs
Date: March 2 2009 1:35am
Subject: how to force index using.
List-Archive: http://lists.mysql.com/internals/36314
Message-Id: <6241f7fc0903011735o28aeb03cna77f8edd7fcc9881@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

I give lying information in the info() function and records_in_range()
to force the query using index.
For example: 'id' is key. When the query is like 'select ... from ..
where id = 5', the index is used. But when it comes to range query
like ''select ... from .. where id > 5', full table scan is used.