Re: Is mysql a RDBMS ?

From: Pablo Sanchez <honeypot_at_blueoakdb.com>
Date: 25 Aug 2003 16:07:19 GMT
Message-ID: <Xns93E27B3C0A94Epingottpingottbah@192.168.1.1>

"Heikki Tuuri" <Heikki.Tuuri_at_innodb.com> wrote in news:52h2b.18$G37.11_at_read3.inet.fi:

>> DISTINCT often improves performance by allowing the dbms to
>> ignore 

> potential

>> duplicates that very often cannot even exist.

>
> Can you show statistics about that?

DISTINCT's often require a sort area to squish out dup's, which means a performance degradation.

-- 
Pablo Sanchez, Blueoak Database Engineering
http://www.blueoakdb.com

Received on Mon Aug 25 2003 - 11:07:19 CDT