VSAM Programming with COBOL

This course introduces the additional considerations when coding COBOL application programs to access and maintain VSAM files. Using a combination of classroom tuition and extensive hands-on exercises, attendees will learn to code application programs that are able to read and write to VSAM KSDS, ESDS and RRDS data sets. Sequential, random and dynamic access will all be demonstrated, as will the use of alternate indexes where applicable.

This course is available for one-company, on-site presentations.

What you will learn

On successful completion of this course you will be able to:

  • describe the differences in accessing VSAM KSDS, ESDS and RRDS data sets
  • code application programs to read from and write to VSAM data sets using the READ, WRITE, DELETE, REWRITE and START commands
  • understand and use VSAM status codes and return codes
  • understand the use of alternate indexes when accessing VSAM data sets.

Who Should Attend

This course is intended for COBOL application programmers needing a greater insight into accessing VSAM data from the application programs.


An understanding of COBOL programming in a mainframe environment is assumed. A basic understanding of VSAM files would be advantageous.


2 days

Fee (per attendee)


Course Code



Using VSAM Files

VSAM basics; VSAM KSDS, ESDS and RRDS data sets; using Access Method Services (AMS) to define, delete, load and print VSAM files.

Reading VSAM Data in a COBOL Program

Identifying the file as VSAM; OPEN and CLOSE of VSAM data sets; file status and retrn codes; reading VSAM data sequentially, randomly and dynamically.

Modifying VSAM Data in a COBOL Program

WRITE using sequential access; WRITE using index access; the DELETE statement; the REWRITE statement; handling invalid keys.

Using Alternate Indexes

Alternate indexes and paths; defining alternate indexes and paths; identifying the alternate index in COBOL; processing VSAM data using the alternate index.

Hands-on Exercises

Extensive hands-on exercises throughout the course reinforce the material covered.

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