SAS/CONNECT User's Guide

Using Data Views with Servers

The Remote Library Services (RLS) features of the SAS System can be used with three types of views:

SAS/ACCESS views
DATA step views
PROC SQL views.

A view is a SAS file that contains no data, but it describes other data. A view is processed by an engine that reads the underlying data and uses the description to return the data in the requested form. This process is called view interpretation.

When the library that contains the view is accessed through a server, the view is interpreted in the server's session by default. This means that the engine is loaded and called by the server to read and transform the underlying data. Only a small amount of data is moved through the network, and the local processing is unaware that a view is involved.

If the view is a PROC SQL view or if the local and remote machine architectures are the same, you can cause the view to be interpreted in the local session. This is done by specifying RMTVIEW=NO in the LIBNAME statement that is used to define the remote library. If the architectures are not the same, SAS/ACCESS views and DATA step views can only be interpreted in the remote session.

Interpreting a view as data can produce significant processing demands. When a view is interpreted locally, that frequently means that a lot of data has to flow to the local session. This removes processing demands from the server session but increases network load, which is usually not desired.

Recommendations for PROC SQL Views

PROC SQL views are especially good candidates for interpretation in a remote SAS session if

the number of observations that are produced by the view is much smaller than the number of observations that are read by the view.
the data sets that are read by the view are available to the server.
the amount of processing necessary to build each observation is not large.

Conversely, PROC SQL views should be interpreted in users' SAS sessions if

the number of observations that are produced by the view is not appreciably smaller than the number of observations that are read by the view.
some of the data sets that are read by the view can be directly accessed by the users' SAS sessions.
the amount of processing that is done by the view is considerable.

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