Here are ideas on how to access VSAM files in COBOL.
VSAM File Features
- Entries in Master or User catalog is possible for VSAM datasets.
- In general, the Master catalog and User-catalog both can have entries of VSAM and non-VSAM datasets.
- Only KSDS datasets have Indexed. ESDS and RRDS do have only the data components. That means they do not have an index.
- |Data component|Index component|
- While working with ESDS and RRDS you no need to use index.
- KSDS has an index is a combination of Key and Value. KSDS also supports an alternate index.
- Index key|Sequence value
- In KSDS first, it locates the index, then finds corresponding sequence value later it get data from control interval and area.
- The catalog that stores both VSAM and non-VSAM datasets information is called the ICF integrated catalog facility.
How to access VSAM files in COBOL
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.