SAS interacts
with
CA-Datacom/DB through an
interface view engine that uses
SAS/ACCESS descriptor files created
with the ACCESS procedure. There are two types of descriptor files:
An access descriptor contains information about the
CA-Datacom/DB table that you want to use. The information includes the table name, the
field names, and their data types. You use the access descriptor to create
view descriptors. Think of an access descriptor as a master
descriptor file for a single
CA-Datacom/DB table, because it usually contains
a complete description of that table.
A view descriptor defines a subset of the data described by an access descriptor.
You choose this subset by selecting particular fields in the
CA-Datacom/DB table, and you can specify selection criteria that the data must meet. For example,
you might want to select two fields, LAST-NAME and CITY-STATE, and specify that the
value stored in field 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
CA-Datacom/DB table or to extract the data and place it in a
SAS data file. Typically, for each access descriptor that you define, you have several view descriptors,
each selecting different subsets of data.