What is the significance of the RECORD KEY clause when defining VSAM and ISAM files in COBOL?
- It defines the length of each record in the file
- It identifies the field used as a key to uniquely identify records in the file
- It indicates the position of the record within the file
- It specifies the physical location of the file on the disk
The RECORD KEY clause in COBOL is significant when defining VSAM and ISAM files as it identifies the field used as a key to uniquely identify records in the file. This key is essential for direct access to specific records.
You are developing a COBOL application that requires modeling real-world entities and their relationships. Which Object-Oriented COBOL concept would you use to achieve this?
- Abstract Data Types
- Encapsulation
- Inheritance
- Polymorphism
In Object-Oriented COBOL, Inheritance is used to model real-world entities and their relationships. It allows a class to inherit attributes and behaviors from another class, promoting code reusability and representing an "is-a" relationship.
The MERGE statement in COBOL is often used for _____ files with a common key.
- Combining
- Indexing
- Merging
- Sorting
The MERGE statement in COBOL is used for merging files with a common key. It allows records from multiple sorted input files to be merged into a single sorted output file based on the specified key.
In COBOL, what happens when you open a file in "Output" mode that already exists?
- It appends the new data to the existing file
- It deletes the existing file
- It overwrites the existing file with the new data
- It raises a compilation error
When a file is opened in "Output" mode in COBOL, it overwrites the existing file with the new data. This mode is used for creating a new file or replacing the content of an existing one.
What is a cursor in COBOL when dealing with database operations?
- A control structure used to iterate over database records
- A database object used to store query results
- A mechanism to establish database connections
- An index used to optimize database queries
In COBOL, a cursor is a control structure used to iterate over the result set of a SQL query. It enables sequential access to individual rows returned by the query, allowing COBOL programs to process database records one at a time. Cursors are essential for handling database operations involving multiple rows of data.
What is the significance of the INPUT PROCEDURE in a COBOL SORT statement?
- Defines the criteria for output record selection
- Provides a procedure to be executed before sorting starts
- Specifies the condition to be met for input records
- Specifies the output file for sorted records
The INPUT PROCEDURE in a COBOL SORT statement allows the programmer to specify a procedure that will be executed before the sorting process begins. It is commonly used for tasks such as data manipulation or validation before sorting.
When defining an array or table in COBOL, you must specify the _____ of elements it can hold.
- INDEX
- OCCURS
- RANGE
- SIZE
When defining an array or table in COBOL, the OCCURS clause is used to specify the number of elements it can hold. It determines the size or occurrence of the table, indicating how many times a data item should repeat.
When performing division in COBOL, which operator should you use?
- *
- +
- -
- /
The forward slash (/) operator is used for division in COBOL. For instance, "DIVIDE operand1 BY operand2 GIVING result." is a division operation in COBOL.
How is encapsulation achieved in Object-Oriented COBOL?
- By bundling data and methods within a class
- By separating data and procedures
- Through external subroutine calls
- Through the use of global variables
Encapsulation in Object-Oriented COBOL is achieved by bundling data and methods within a class. This means that the internal details of the class, such as data structures and implementation details, are hidden from the outside world, promoting information hiding and reducing complexity.
The LEVEL NUMBER in COBOL indicates the ________ of the data item.
- Address
- Hierarchy
- Size
- Type
The LEVEL NUMBER in COBOL indicates the hierarchical level of the data item. It specifies the position of the data item within the data hierarchy, helping in organizing and structuring data.