VSAM organizations – identifying dataset types Which of the following are valid file organization components of an IBM VSAM file?

Introduction / Context:
VSAM (Virtual Storage Access Method) is an IBM mainframe file access method that supports multiple dataset organizations tailored to different access patterns and key structures.

Given Data / Assumptions:

• Common VSAM organizations include KSDS, ESDS, and RRDS.
• Each organization suits particular workloads (keyed, sequential, or relative access).
• The options list these acronyms in expanded form.

Concept / Approach:

KSDS (Keyed Sequential Data Set) supports key-based access and sequential processing; ESDS (Entry Sequential Data Set) supports strictly sequential access by entry order; RRDS (Relative Record Data Set) uses relative record numbers for direct access. All are standard VSAM organizations.

Step-by-Step Solution:

Verification / Alternative check:

IBM documentation enumerates KSDS, ESDS, and RRDS as the three principal VSAM dataset organizations (plus LDS in later contexts).

Why Other Options Are Wrong:

Each individual option names a valid VSAM type, so “None of the above” is incorrect; “all of the above” is the only fully correct aggregate choice.

Common Pitfalls:

Confusing ESDS (entry order) with purely sequential flat files outside VSAM; forgetting the existence of RRDS with fixed slots addressed by relative number.

Final Answer:

all of the above.