ADABAS Databases

Definition of an ADABAS DBMS Database

An ADABAS database is a collection of data organized into ADABAS files. Each database has an associated database identifier, which is a numerical value in the range 1 to 65,535, and a database name, which is a character value with a maximum of 16 characters. Each database can consist of up to 5,000 logical files.

An ADABAS database consists of three system files: Data Storage, Associator, and Work Storage.

The Data Storage system file contains the actual data records for all ADABAS files in a database, in compressed form.
The Associator system file contains internal storage information that manages the data for the entire database.
The Work Storage system file contains temporary work files.

To use the SAS/ACCESS interface to ADABAS, you need to be familiar with three ADABAS components: ADABAS files, NATURAL DDMs, and ADABAS descriptors (which is an ADABAS data field that provides an index of its values). ADABAS files and NATURAL DDMs are the components from which you create SAS/ACCESS access descriptor and view descriptor files. Knowing about ADABAS descriptors can help you minimize ADABAS's processing time for your SAS/ACCESS view descriptors.

Note: To avoid confusion, keep in mind the two usages of the term descriptor throughout this document:

An ADABAS descriptor is an ADABAS data field that provides an index of the data field's values.
SAS/ACCESS descriptor files, on the other hand, are the files used to establish a connection between SAS and ADABAS.

The following sections describe ADABAS files, NATURAL DDMs, and ADABAS descriptors.

ADABAS Files

Definition of an ADABAS File

An ADABAS file is a collection of logically related data, organized by data fields and logical records. ADABAS permits maximums of 926 data fields and 4,294,967,294 logical records in each ADABAS file.

The following output illustrates four data fields and seven logical records from an ADABAS file containing data about customers. The data fields are the vertical columns of data. The logical records are the horizontal rows of data.

Sample ADABAS File

       
CU           CI               ST        CO

14324742     San Jose         CA        USA     
14569877     Memphis          TN        USA
14898029     Rockville        MD        USA
24589689     Belgrade                   Yugoslavia
26422096     La Rochelle                France
38763919     Buenos Aires               Argentina
46783280     Singapore                  Singapore

ADABAS files are created with the ADABAS utility ADACMP. (To see the ADABAS data definition statements that created the ADABAS files used in this document, see Example Data.)

ADABAS File Number

When you create an ADABAS file, you assign a file number using the FILE= statement of the ADACMP utility. Each database can consist of up to 5,000 logical files, depending on the device type.

Level Number

A data field level number is a one- or two-digit number, from 01 to 07, used in conjunction with data field grouping. (Grouping is discussed in ADABAS Data Fields.) Data fields with a level of 2 or greater are considered to be a part of the immediately preceding group, which has a lower level number.

Data Field Names

ADABAS data fields are identified by a two-character name. Each data field name in an ADABAS file must be unique. The first character must be alphabetic, and the second character can be either alphabetic or numeric. For example, AA and B4 are valid data field names.

Logical Record ISN

Each logical record within an ADABAS file is assigned an internal sequence number (ISN). An ISN is the logical identifier for each record. ISNs are unique within each ADABAS file.

Note: When you create SAS/ACCESS descriptor files for ADABAS data, the ACCESS procedure creates a SAS variable named ISN. This variable gives you access to the ISNs for all logical records stored in the ADABAS file.