In COBOL, what are the advantages of using subprograms?
- Code Reusability, Maintainability, and Improved Readability
- Enhanced Input/Output Operations
- Improved Control Flow
- Increased Program Complexity, Slower Execution
Using subprograms in COBOL offers advantages such as code reusability, maintainability, and improved readability. By breaking down a program into smaller modules, developers can reuse code segments, making it easier to maintain and understand the program.
In COBOL, to open a file for both reading and writing, you typically use the _____ access mode.
- EXTEND
- I-O
- INPUT
- OUTPUT
The I-O (Input-Output) access mode in COBOL is used to open a file for both reading and writing operations. This allows the program to perform a combination of read and write operations on the same file.
You are developing a COBOL program that reads data from an external file. What would you do if the file does not exist when you attempt to open it?
- Check the FILE STATUS after the OPEN statement
- Perform a manual check using IF conditions
- Use the INVALID KEY clause in the file control entry
- Utilize the EXIT PROGRAM statement
When attempting to open a file, using the INVALID KEY clause in the file control entry allows you to handle the situation where the file does not exist. You can specify a set of actions to be taken if the file opening fails, providing a mechanism for graceful error handling.
When defining a data type in COBOL, the _____ clause is used to specify the number of characters or digits that a field can hold.
- LENGTH
- OCCURS
- PICTURE
- SIZE
The SIZE clause in COBOL is used to specify the number of characters or digits that a field can hold. It helps allocate the appropriate amount of storage for a data item.
In a complex COBOL program, you notice the extensive use of the "LINKAGE SECTION." What is the primary purpose of this section, and when is it commonly used?
- It declares variables used only within the called subprogram
- It defines data items shared between a calling program and a called subprogram
- It indicates the sequence of program execution
- It specifies the input-output operations for external files
The "LINKAGE SECTION" in COBOL is used to define data items shared between a calling program and a called subprogram. It allows data to be passed between programs, facilitating communication and data sharing in a modular and organized manner.
In a COBOL program, you need to execute a stored procedure to update customer records in a database. How would you achieve this?
- EXEC SQL CALL
- EXEC SQL DECLARE
- EXEC SQL OPEN
- EXEC SQL UPDATE
To execute a stored procedure in COBOL, you would use the EXEC SQL CALL statement. This statement is specifically designed for invoking stored procedures in a database, allowing you to update customer records or perform other operations.
You are tasked with processing sales transaction data, and some transactions may be recorded twice due to system glitches. How would you ensure that such duplicate transactions are detected and managed correctly?
- Implement a check during data entry to prevent duplicate transactions
- Perform a sequential search on the transaction data to identify duplicates
- Use a COBOL program to perform a hash function on transaction IDs
- Utilize a COBOL file control system to flag and handle duplicate transactions
Utilizing a COBOL file control system to flag and handle duplicate transactions is a robust approach. This involves setting up mechanisms to detect and manage duplicates during the processing of sales transaction data, ensuring data accuracy and integrity.
In COBOL, what is the role of the SORT statement when handling duplicate records?
- It arranges records in ascending order based on the specified key
- It has no impact on duplicate records
- It removes duplicate records from the file
- It separates duplicate records into a separate file
The SORT statement in COBOL, when used with the DUPLICATES phrase, segregates duplicate records into a separate output file, allowing for distinct processing of such records.
What is the significance of the REDEFINES clause when defining data items in COBOL?
- It allows two or more data items to share the same storage space
- It declares a constant value for a data item
- It defines a new record format for a file
- It specifies the length of a data item
The REDEFINES clause in COBOL is used to allow two or more data items to share the same storage space. This can be useful for representing the same data in different formats or units, optimizing memory usage.
In COBOL, the REDEFINES clause is often employed for optimizing memory usage, especially when working with _____
- Arrays
- Binary data
- Complex structures
- Numeric
The REDEFINES clause in COBOL is used to allow different data items to share the same storage space. This is particularly useful when working with complex structures to optimize memory usage.
Your COBOL program needs to process a large dataset of financial transactions that must be read in a specific order. Which file processing technique is most appropriate?
- Indexed processing
- Relative processing
- Sequential processing
- Sort the dataset before processing
For processing data in a specific order, Sequential processing is appropriate. This ensures that records are processed in the order they appear in the file.
Your COBOL program manages a customer database, and you want to implement file locking for concurrent access. What factors should you consider when choosing between record-level and file-level locking?
- Data consistency needs
- Database size
- Performance requirements
- Transaction complexity
When choosing between record-level and file-level locking in a COBOL program managing a customer database, factors like data consistency needs should be considered. File-level locking ensures consistent access to the entire file, while record-level locking provides more granular control but may require additional management of locks.