Using SAS DATA Step Views to Conserve Data Storage Space

A SAS data view is a type of SAS data set that retrieves data values from other files. A SAS data view only contains descriptor information such as the data types and lengths of the variables, plus information that is required for retrieving data values from other SAS data sets or from files that are stored in other software vendors' file formats.

SAS data views are of member type VIEW.

In most cases, you can use a SAS data view as though it were a SAS data file. Example 1 shows how to create a view:

Example 1:

data sasuser.at_risk / view=sasuser.at_risk;

set work.students;

where at_risk = '1';

run;

The VIEW= option tells SAS to compile (but not execute) the source program and to store the compiled code in the input DATA step view.

You can use a DESCRIBE statement in a DATA step to write a copy of the source code for a data set view to the SAS log:

Example 2:

data view=sasuser.at_risk;

describe;

run;

The log from this data step will show the source code used to create the view.

SAS Data View Benefits

You can save disk space by storing a view definition, which stores only the instructions for where to find the data and how it is formatted, not the actual data.

Views can ensure that the input data sets are always current because data is derived from views at execution time.

Since views can select data from many sources, once a view is created, it can provide prepackaged information without the need for additional programming.

Views can reduce the impact of data design changes on users. For example, you can change a query that is stored in a view without changing the characteristics of the view's result.

With SAS/CONNECT software, a view can join SAS data sets that reside on different host computers, presenting you with an integrated view of distributed data.

You can use views as input to other DATA steps or PROC steps and in combination with other data sources using PROC SQL.

When to Use SAS Data Views

Consider the following in order to determine whether a SAS data file or a SAS data view is better for your purposes:

Data files use additional disk space; data views use additional processing time.

Data file variables can be sorted and indexed prior to use; data views must process data in its existing form during execution.