From: Ed Carp
Date: March 29 1999 5:51am
Subject: Re: Question about query
List-Archive: http://lists.mysql.com/mysql/1121
Message-Id: <004201be79a8$41842b00$74c9a8c0@traveler.airmail.net>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

>I have a query like
>select id from atable where truncate(c1/1000000) = 321
>
>I learned that following query has the same function
>select id from atable where c1 like '321______'
>
>I'd like to know which is faster. Or anyone know how to do integer division
>in MySQL faster.
>
>And if I make a index on c1 or a index on c1/1000000, which index will
>increase the query speed, or none index is helpful.


I hate to be a curmudgeon (again) but wouldn't it be easier and faster to
test it on your own machine than posting to a mailing list and essentially
asking someone else to do your work for you?

Indexing a field is generally always faster, but this depends on your
application.  Again, test it on your own machine with a big recordset and
time it to see which is faster.