In VSAM processing, what are some common VSAM error conditions and how are they usually reported to application programs?

Introduction / Context:
VSAM access is accompanied by detailed status information that helps applications respond to problems and boundary conditions. Understanding which common error conditions can occur and how they are communicated is vital for writing robust COBOL or other mainframe programs that use VSAM datasets. This question connects knowledge of typical error situations with an understanding of file status handling.

Given Data / Assumptions:

• COBOL or other languages use VSAM files with FILE STATUS clauses.
• Operations such as READ, WRITE, REWRITE, and DELETE may encounter various issues.
• Typical conditions include record not found, duplicate key, end of file, and out of space.
• VSAM can also provide extended status via additional fields such as VSAM code.

Concept / Approach:
When VSAM detects conditions like an attempt to read a non existent record or write a duplicate key into a KSDS, it does not silently ignore these issues. Instead, it sets file status codes that the application can check. There may also be extended VSAM return codes that provide more detail. The correct answer must mention both common error types and the mechanism of file status reporting.

Step-by-Step Solution:
Step 1: Recall typical VSAM related file status conditions, such as key not found or duplicate key. Step 2: Remember that COBOL programs receive these conditions through the two character file status field and sometimes a longer VSAM status field. Step 3: Find the option that correctly names several common error types and states that they are reported through file status codes. Step 4: Eliminate answers that claim VSAM never reports errors or only prints messages, which would not support robust error handling. Step 5: Choose the option that matches well known mainframe documentation and coding practices.

Verification / Alternative check:
You can verify this by recalling COBOL code examples that test FILE STATUS after a VSAM READ or WRITE. Condition values such as 10 for end of file or 23 for record not found are standard. There are also extended status fields for more detail. No programming guide suggests that VSAM hides these conditions or reports them only at the console, confirming that the file status based option is correct.

Why Other Options Are Wrong:
Option b: Suggesting that VSAM always returns success is incorrect and would make reliable programs impossible.
Option c: Ignoring logical conditions such as duplicate key would violate data integrity and is not how VSAM behaves.
Option d: Operator console messages may exist, but they are not the primary mechanism for application level error handling.

Common Pitfalls:
A common pitfall is failing to code FILE STATUS in COBOL and therefore missing important error signals. Another mistake is to log file status codes without interpreting them, making troubleshooting difficult. For best practice, always define file status fields, check them after operations, and handle common conditions like not found and end of file explicitly.

Final Answer:
Errors such as record not found, duplicate key, end of file, and out of space are reported through file status codes and sometimes extended VSAM codes.