Re: Teach SELECT DISTINCT first!
From: Laconic2 <laconic2_at_comcast.net>
Date: Thu, 29 Apr 2004 09:15:12 -0400
Message-ID: <HoGdnWJVu-o1Yg3dRVn-vw_at_comcast.com>
Date: Thu, 29 Apr 2004 09:15:12 -0400
Message-ID: <HoGdnWJVu-o1Yg3dRVn-vw_at_comcast.com>
You are right. At least half of the time, people who come to me with an SQL query that performs badly have a logical error in the query that results in unwanted duplicates as well as poor performance. But they are more concerned about the poor performance than about the erroneous results. That's another discussion.
Sometimes, the selection of duplicates arises from a poorly designed schema, rather than a poorly designed query. Or both.
Apart from these minor points, I agree with you. Received on Thu Apr 29 2004 - 15:15:12 CEST