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| Defining SAS/ACCESS Descriptor Files |
SAS/ACCESS Descriptor Files Essentials
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.
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