SAS/ACCESS Interface to SYSTEM 2000 Data Management Software: Reference

Understanding SAS/ACCESS Descriptor Files

The SAS System interacts with SYSTEM 2000 software through an interface view engine that uses SAS/ACCESS descriptor files. There are two types of descriptor files:

access descriptor files (member type ACCESS)
view descriptor files (member type VIEW)

An access descriptor contains information about the SYSTEM 2000 database you want to use. The information includes the database name, the item names, and their item types. You use the access descriptor to create view descriptors. Think of an access descriptor as being a master descriptor file for a single SYSTEM 2000 database because it usually contains a complete description of that database.

A view descriptor defines a subset of the data described by an access descriptor. You choose this subset by selecting particular items, and you can specify selection criteria that the data must meet. For example, you may want to select two items, LAST NAME and CITY-STATE, and specify that the value stored in item CITY-STATE must be AUSTIN TX. You can also specify a sequence order for the data.

After you create your view descriptor, you can use it in a SAS program to read data directly from the SYSTEM 2000 database or to extract the data and place them in a SAS data file. Typically, for each access descriptor that you define, you have several view descriptors, each selecting different subsets of data.

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