Re: Informix SQL question

Candy, It doesn't matter what order you specify the columns in you will always get the same query plan. It also doesn't matter if you have where a = '1' or where '1' = a. Regards David Ashby ______________________________ Reply Separator _________________________________ Subject: Informix SQL question Author: "Candy McCall" <candym@olcinc.com> at WCA-INET Date: 03/6/98 10:58 PM I have a simple question. Suppose you have a table whose primary key is a composite key of the columns col1,col2,col3,col4 (primary key is in that order). If you do a query to fetch a record by the primary key, does it matter what order you ask for the columns in the where clause? For example, does SELECT * FROM someTable WHERE col4=? AND col1=? AND col2=? AND col3=? get the record as efficiently as the statement SELECT * FROM someTable WHERE col1=? AND col2=? AND col3=? AND col4=? I always order the columns in the where clause in the order of the primary key or the index I'd like the optimizer to use. I've noticed in the IBM Visual Age for Java that some of the code generated to retrieve a row by a primary key may mix up the order. Thanks! Candy -- Candy McCall ONLINE Computing, Inc. (candym@olcinc.com)