How to Read VSAM File Randomly in COBOL

Here’s a sample COBOL program that reads VSAM file randomly. The logic given here is helpful to use in your projects.

Storage of VSAM Files

Entries will store in Master or User catalog
Plainly, the Master and User-catalog both can have entries of VSAM and non-VSAM datasets.
Only KSDS datasets have Indexed. The ESDS and RRDS have only the data components. That means they do not have an index.
- |Data component|Index component|
While working with ESDS and RRDS you need not index.
KSDS index is a combination of Key and Value. Also, KSDS supports an alternate index.
- Index key|Sequence value
In KSDS, firstly, it locates the index, then finds corresponding sequence value. From this it gets data from control interval and area.
The catalog that stores information of VSAM and non-VSAM datasets is called the ICF integrated catalog facility.

VSAM COBOL Example Program Read Today

How to READ VSAM Files Randomly

SELECT TEST1 ASSIGN TO TEST1
  ORGANIZATION IS INDEXED 
  ACCESS IS RANDOM 
  RECORD-KEY IS         TS-EMPLOYEE-NUMBER 
  ALTERNATE RECORD KEY IS TS-SOCIAL-SECURITY-NO 
  ALTERNATE RECORD KEY IS TS-DEPT-NO 
                  WITH DUPLICATES.