-
WHERE-expression
processing
- allows you to conditionally select a subset of observations,
so that the SAS System processes only the observations that meet a set of
specified conditions. For example, if you have a SAS data set containing sales
records, you may want to print just the subset of observations for which the
sales are greater than $300,000 but less than $600,000. In addition, WHERE-expression
processing may improve efficiency of a request. For example, if a WHERE expression
can be optimized with an index, SAS does not have to read all observations
in the data set to perform the request.
- WHERE expression
- defines a condition that selected observations must satisfy
in order to be processed. You can have a single WHERE expression, referred
to as a simple expression, such as
where sales gt 600000;
Or you can have multiple WHERE expressions, referred to as a compound expression, such as
where sales gt 600000 and salary lt 100000;
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
