To help you decide between a DATA step view and a PROC SQL view, remember
the characteristics of each type of view:
- DATA step views
- DATA step views are very
versatile because they can harness the
power of SAS DATA step processing, including DO loops and IF-THEN-ELSE statements.
- DATA step views do not have write capability, that is, they cannot
directly change the data that they can access.
- There is no way to qualify the data in a DATA step view prior
to using it therefore, even if you need only part of the data in your data
view, you must load into memory the entire DATA step view and discard everything
that you don't need.
- PROC SQL views
- PROC SQL views can
combine data from many different file formats.
- PROC SQL views can both read and update the data that they reference.
- PROC
SQL supports more types of WHERE clauses than are available
in DATA step processing and has a CONNECT TO component that allows you to
easily send SQL statements and pass data to a DBMS by using the Pass-Through
Facility.
- You can also use the power of the SQL language to subset your
data prior to processing it. This saves memory when you have a large view,
but need to select only a small portion of the data contained in the view.
- PROC SQL views do not use DATA step
programming.
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.