What is the purpose of the GLOBAL clause in COBOL for variable declarations?
- It allows variables to be shared among multiple programs
- It defines variables with global visibility
- It enables dynamic memory allocation for variables
- It restricts the scope of variables to the current program
The GLOBAL clause in COBOL is used to declare variables with global visibility, allowing them to be shared among multiple programs. This facilitates communication and data sharing between different program units.
What is the purpose of the relative record number in relative file organization?
- It allows for direct access to records
- It is used for sorting records
- It represents the position of the record in the file
- It uniquely identifies records in a file
The relative record number in relative file organization serves the purpose of allowing direct access to records. It represents the position of the record in the file relative to the beginning, facilitating random access based on the relative record number.
When a CONTINUE statement is encountered, it allows the program to ___________ executing subsequent statements in the same scope.
- Bypass
- Interrupt
- Maintain
- Resume
When a CONTINUE statement is encountered in COBOL, it allows the program to resume executing subsequent statements in the same scope, effectively bypassing the error handling code.
How is an indexed file different from a sequential file in COBOL?
- Indexed files allow direct access to records using a key, while sequential files are accessed sequentially from the start to end
- Indexed files are smaller in size compared to sequential files
- Sequential files are read-only, while indexed files support both read and write operations
- Sequential files are suitable for large datasets, while indexed files are better for small datasets
The primary distinction is that indexed files in COBOL enable direct access to records using a key, offering efficient retrieval based on specific criteria. In contrast, sequential files are accessed sequentially from the beginning to end, making them suitable for large datasets.
In an indexed file system, you notice that certain records are accessed frequently, while others are rarely accessed. How can you optimize the performance of record retrieval for frequently accessed records?
- Clustering frequently accessed records together
- Implementing a multi-level index
- Increasing the size of the index file
- Using alternate indexes
Clustering involves physically arranging records in the file so that frequently accessed records are stored close together. This reduces the number of disk accesses required to retrieve these records, thereby improving performance for frequently accessed data.
_____ is a strategy for handling duplicate records by aggregating data based on a common key.
- Aggregate
- Group By
- Rollup
- Summarize
The Group By strategy in COBOL involves aggregating data based on a common key, allowing for the consolidation and summarization of records with similar key values.
In COBOL, the "ELSE" clause is executed when the condition in the "IF" statement is _____
- FALSE
- False or Undefined
- TRUE
- Undefined
The "ELSE" clause in COBOL is executed when the condition in the "IF" statement is False. If the condition is True, the statements following the "ELSE" clause are skipped. If the condition is False or Undefined, the "ELSE" clause is executed.
When might you use the REDEFINES clause in a COBOL program?
- To control program flow
- To declare a new variable
- To optimize program execution
- To represent the same data in different formats
The REDEFINES clause in COBOL is used when you want to represent the same data in different formats. It helps conserve memory by allowing different data items to use the same storage space.
In COBOL, the index file associated with an indexed file is used to provide _____ access to records.
- Direct
- Random
- Relative
- Sequential
In COBOL, an indexed file is associated with an index file that allows direct access to records based on the values in the indexed field. This provides efficient access to specific records without the need to sequentially read through the entire file.
The _____ statement in COBOL is commonly used to handle variable-length records based on a condition.
- EVALUATE
- IF
- PERFORM
- SEARCH
The "EVALUATE" statement in COBOL is commonly used to handle variable-length records based on a condition. It allows for structured conditional processing, making it suitable for scenarios involving variable record lengths.