SAS 9.4 Language Reference, 6th Edition

You can use SAS views in the following ways:

• as input to other DATA steps or PROC steps

• to migrate data to SAS data files or to database management systems that are

supported by SAS

• in combination with other data sources using PROC SQL

• as pre-assembled sets of data for users of SAS/ASSIST software, enabling them to

perform data management, analysis, and reporting tasks regardless of how the data is

stored

When to Use SAS Views

Consider the following in order to determine whether a SAS data file or a SAS view is

better for your purposes:

• Data files use additional disk space; SAS views use additional processing time.

• Data file variables can be sorted and indexed before using; SAS views must process

data in its existing form during execution.

DATA Step Views

Definition of a DATA Step View

A DATA step view is a native view that has the broadest scope of any SAS view. It

contains a stored DATA step program that can read data from a variety of sources,

including:

• raw data files

• SAS data files

• PROC SQL views

• SAS/ACCESS views

• DB2, ORACLE, or other DBMS data

Creating DATA Step Views

In order to create a DATA step view, specify the VIEW= option after the final data set

name in the DATA statement. The VIEW= option tells SAS to compile, but not to

execute, the source program and to store the compiled code in the input DATA step view

that is named in the option.

For example, the following statements create a DATA step view named Dept.A:

libname dept 'SAS-library';

data dept.a / view=dept.a;

… more SAS statements …

run;

DATA Step Views 677

If the SAS view exists in a SAS library and if you use the same member name to create a

new view definition, then the old SAS view is overwritten.

Beginning with SAS 8, DATA step views retain source statements. You can retrieve

these statements using the DESCRIBE statement. The following example uses the

DESCRIBE statement in a DATA step view in order to write a copy of the source code

to the SAS log:

data view=inventory;

describe;

run;

For more information about how to create SAS views and use the DESCRIBE statement,

see the DATA statement in SAS DATA Step Statements: Reference.

What Can You Do with a DATA Step View?

Using a DATA step view, you can do the following:

• directly process any file that can be read with an INPUT statement

• read other SAS data sets

• generate data without using any external data sources and without creating an

intermediate SAS data file

Because DATA step views are generated by the DATA step, they can manipulate and

manage input data from a variety of sources including data from external files and data

from existing SAS data sets. The scope of what you can do with a DATA step view,

therefore, is much broader than that of other types of SAS views.

Differences between DATA Step Views and Stored Compiled DATA

Step Programs

DATA step views and stored compiled DATA step programs differ in the following

ways:

• a DATA step view is implicitly executed when it is referenced as an input data set by

another DATA or PROC step. Its main purpose is to provide data, one record at a

time, to the invoking procedure or DATA step.

• a stored compiled DATA step program is explicitly executed when it is specified by

the PGM= option in a DATA statement. Its purpose is usually a more specific task,

such as creating SAS data files, or originating a report.

For more information about stored compiled DATA step programs, see Chapter 30,

“Stored Compiled DATA Step Programs,” on page 685.

Restrictions and Requirements

Global statements do not apply to a DATA step view. Global statements such as the

FILENAME, FOOTNOTE, LIBNAME, OPTIONS, and TITLE statements, even if

included in the DATA step that created the SAS view, have no effect on the SAS view. If

you do include global statements in your source program statements, SAS stores the

DATA step view but not the global statements. When the view is referenced, actual

execution can differ from the intended execution.

When a view is created, the labels for the variable that it returns are also created. If a

DATA step view reads a data set that contains variable labels and a label is changed after

678 Chapter 29 • SAS Views