Today, COBOL (common business-oriented language) is a highly sought-after skill in a number of technical roles—and if you want that job, you’ll need to answer challenging COBOL interview questions.
What makes COBOL an in-demand skill? The common use of the language across essential business, finance, and administrative mainframe systems. An estimated $3 trillion in daily commerce is handled by COBOL systems, creating a competitive and lucrative field where companies want nothing but the best.
To get ahead, candidates need to clearly demonstrate their abilities during interviews. COBOL interview questionsare often highly technical, as employers need to know that candidates can get the job done.
In the following list of COBOL interview questions, you can gauge your knowledge of the language.If you struggle with some of these questions, it might be time to consider COBOL courses to brush up on or develop new skills.
If you’re a recruiter, you can also make use of these COBOL interview questions for 10 years’ experienced candidates to screen for candidates who really know their stuff.
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Review These 14 COBOL Interview Questions
Test your knowledge of COBOL with the interview questions below. Pay extra attention to the COBOL Db2 interview questions below—you never know what your interview will cover.
1.What’s the Difference Between Static Call and Dynamic Call?
Both static call and dynamic call will call a program. However, in a static call, the called program is a standalone executable program. In a dynamic call, this is not the case. Instead, the called program is not an executable program and can only be executed through the called program.
2.Which Isolation Level Can Provide the Highest Data Integrity?
In Db2, there are four isolation levels:
- Cursor stability (CS)
- Repeatable read (RR)
- Read stability (RS)
- Uncommitted read (UR)
Repeatable read provides the highest level of integrity. Under repeatable read isolation, page locks are held until released by a COMMIT or ROLLBACK. Repeatable read is the default isolation level when the isolation level is not specified.
3.How Can You Simulate the EXPLAIN of an Embedded SQL Statement?
The EXPLAIN command can be simulated through the use of a WHERE clause in which a question mark is used in place of the host variables or other unknown values.
4.What Are DBRM and PLAN?
DBRM is the Database Request Module containing the SQL statements extracted from the host language program, obtained by the pre-compiler. The DBRM then serves as the input for the BIND process, which results in the PLAN output.
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5.How Is the EVALUATE Statement Used?
The EVALUATE statement is a case statement that provides a shorthand notation for nested IF statements. Instead of using break, the EVALUATE WHEN conditions instead determine when the statement is executed, and control transfers to the next statement.
6.What Is the Difference Between Binary and Sequential Search?
When using binary search, the table element key values are used in ascending or descending order. The table is halved during the search to find the appropriate elements. Sequential search goes through the table from top to bottom, meaning no specific element order is required, making it better suited for smaller tables.
7.What Are the Maximum Sizes of the CHAR and VARCHAR Data Types in Db2 and How Are They Used?
The CHAR data type has a maximum size of 254 bytes, while the VARCHAR data type has a maximum size of 4046 bytes. VARCHAR is best used when storing strings with variable lengths, while CHAR is more efficient when the length of strings is always the same.
8.What’s the Difference Between Performing a SECTION and Performing a PARAGRAPH?
Performing a SECTION results in all of the paragraphs that are part of that section being performed. Performing a PARAGRAPH, on the other hand, will only cause that specific PARAGRAPH to be performed.
9.What Is the Database Services Component of Db2 Responsible For?
The database services component is responsible for defining, retrieving, and updating user and system data, executing SQL statements, and managing the buffer pool.
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10.Is It Possible to Alter a Table When Another User Is Accessing or Updating Columns?
It is possible to continue altering the table when another user is accessing or updating columns, as the Db2 tables won’t re-structure until any transaction is committed. Any new columns are only included after the transactions in the table are committed. Altering table statements are received from other users and stored.
11.What Is LINKAGE SECTION Used For?
The LINKAGE SECTION passes data from one program to another or from procedure to program. It is the part of a called program that maps to data items inside the working storage of the calling program.
12.What Are Static and Dynamic Linking?
Static linking is where a called subroutine is link-edited into the calling program. Dynamic linking, on the other hand, keeps the subroutine and main program apart where they exist as separate modules. The appropriate option is selected by choosing either DYNAM or NODYNAM as the link edit option.
13.What Component Is Used to Process SQL Statements and Select Access Paths?
Db2 Optimizer is the component that is used to select access paths and process SQL queries. The Db2 optimizer carries out query rewrites based on cost optimization, taking into account system configuration, optimization parameters, database design, and database statistics.
14.What are the Four Divisions of a COBOL Program and What Is Their Purpose?
The four divisions are:
- Identification: Identifies the program.
- Environment: Defines the environment of the written program in terms of both configuration and input-output.
- Data: Identifies data items, allocates memory, and defines names in the program.
- Procedure: Supports the logic behind the program and variable defined by the user.
Other COBOL Interview Questions to Prepare For
These are just a few examples of the types of COBOL interview questions you might find when looking for your next job opportunity or potential job candidate. There’s no doubt that your interview will include questions that are more about you and how you work than your specific knowledge and skills. Companies need to know that they have found someone they can really work with, so they’ll ask questions about how you work, how you handle different types of problems and your overall approach to mainframe.
Along with brushing up on technical questions, you should take some time to think about how you’re going to present yourself. Come up with a few examples of specific times you’ve overcome difficulties and excelled in past roles to really wow your interviewers.
How You Can Answer COBOL-Db2 Interview Questions Confidently
When it comes time for your next job opportunity, you need to know that you can demonstrate your skills and answer COBOL and Db2 interview questions confidently.
Developing your qualifications is vital in IT, and ProTech Training can help you do just that.
ProTech has over 1,500 unique courses in COBOL, Db2, IBM mainframe, and other areas that can help you refine and expand your skills.
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