When using the "USE AFTER EXCEPTION" phrase with the READ statement in COBOL, what happens if the exception condition is not encountered?
- The READ statement will be ignored
- The file will be closed automatically
- The next statement after the READ is executed
- The program will terminate with an error
If the exception condition specified by "USE AFTER EXCEPTION" is not encountered during the READ statement execution, the control will pass to the next statement after the READ. It allows the program to continue execution without interruption.
Explain how COBOL handles file locking and multi-user access when using the "I-O" mode.
- COBOL doesn't support file locking
- COBOL implements record-level locking to ensure data integrity
- COBOL restricts access to one user at a time
- COBOL utilizes system-level file locking mechanisms to prevent conflicts
When using the "I-O" mode in COBOL, file locking and multi-user access are typically handled by system-level mechanisms rather than by COBOL itself. COBOL programs can utilize features provided by the operating system to implement file locking and ensure data integrity in multi-user environments.
In a COBOL program, if you have a numeric data item defined as USAGE COMP-3, what is the effect of applying the REDEFINES clause to it?
- It allows the same data to be referenced using different data descriptions
- It converts the COMP-3 data to COMP data
- It defines a new data item with the same name
- It is not allowed to use REDEFINES with COMP-3
The REDEFINES clause in COBOL allows the same storage space to be referenced using different data descriptions. When applied to a numeric data item with USAGE COMP-3, it enables sharing the same memory location with other data items, potentially of different types.
In COBOL, what are the advantages of using a structured error-handling approach over traditional methods?
- Improved readability, ease of maintenance, and better program control
- Limited support for various types of exceptions
- Minimal impact on program structure
- Reduced program execution speed and increased complexity
A structured error-handling approach in COBOL offers advantages such as improved code readability, ease of maintenance, and better program control. It enhances the overall quality of the program and makes it easier to manage exceptions in a systematic manner.
To avoid file locking-related performance bottlenecks, it's important to consider the appropriate use of _______ locks for different file access patterns.
- Database-level
- File-level
- Record-level
- System-level
To optimize performance and avoid bottlenecks, it's crucial to consider the appropriate use of Record-level locks for different file access patterns. Record-level locks restrict access to individual records, allowing multiple users to work with other records concurrently, minimizing contention and improving overall system efficiency.
You are reviewing a COBOL program and come across the "FILE SECTION" within the "DATA DIVISION." What type of information is typically defined in this section?
- Data description entries for files used by the program
- Declarations of working storage variables
- Definitions of subprograms
- Specifications for screen layouts
The "FILE SECTION" in the "DATA DIVISION" of a COBOL program is where data description entries for files used by the program are defined. It includes details such as file names, record structures, and access modes.
How does COBOL handle record locking when multiple programs access the same file in "I-O" mode?
- COBOL automatically handles record locking, preventing conflicts
- COBOL doesn't support record locking in "I-O" mode
- COBOL relies on the operating system for record locking
- COBOL uses exclusive lock, allowing only one program to access the file at a time
COBOL typically relies on the underlying operating system for record locking when multiple programs access the same file in "I-O" (Input-Output) mode. It doesn't inherently provide built-in record locking mechanisms.
What is the result of dividing an integer by zero in COBOL?
- Arithmetic Exception
- Compiler Error
- Infinity
- Zero
Dividing an integer by zero in COBOL results in an arithmetic exception. The program will encounter a runtime error due to division by zero, and appropriate error handling should be implemented to address such scenarios.
Explain the significance of the SHAREOPTION clause when dealing with VSAM indexed files in a multi-user environment.
- ALLOWREAD
- DENYNONE
- DENYREAD
- DENYWRITE
The SHAREOPTION clause in COBOL is crucial when dealing with VSAM indexed files in a multi-user environment. It specifies the level of file sharing allowed among users. DENYWRITE, for example, prevents other users from writing to the file simultaneously, ensuring data integrity.
How is a national (Unicode) character data type defined in COBOL?
- COBOL does not support Unicode
- PIC N
- PIC U(10)
- PIC X(10) UNICODE
In COBOL, a national (Unicode) character data type is defined using the PIC N clause. This allows the representation of Unicode characters in the program, ensuring compatibility with international character sets.