Introduction To Mainframe Interview Questions and Answers

The mainframe is a high-performance computer used for large-scale computing purposes that require greater availability and security than a smaller-scale machine can offer. It has the most user-friendly connectivity, single thread performance, and reliability factors. Traditionally, mainframes were related to instead of distributed computing. So If you are looking for a job that is related to Mainframe, you need to prepare for the 2020 Mainframe Interview Questions. Though every interview is different and the scope of a job is also different, we can help you out with the top Mainframe Interview Questions and Answers, which will help you take the leap and get your success in your interview.

In this article, we have covered the top 10 Mainframe Interview Questions and Answers. These questions are divided into two parts which are as follows:

Part 1 – Mainframe Interview Questions (Basic)

This first part covers basic Interview Questions and answers

1. What is a mainframe?

Answer:
A mainframe is also known as “big iron”. It is a large and multi-user computer device that helps to perform TIPS per second. Traditionally, mainframes were related to instead of distributed computing, Distinction is blurring smaller between traditional centralized computing and distributed computing because small computers become additional powerful and mainframes become additional multi-purpose.

2. What is the difference between HIDAM and HDAM databases?

Answer:

HIDAM	HDAM
HIDAM is employed for serial access similarly as random access	HDAM is employed for random access
HIDAM requires 2 I/O one to the index and one to the data to provide direct access to root via the HIDAM index	HDAM provides quick direct access to root via the randomizer.
HIDAM encompasses a separate index file that relies on the basics section.	On the opposite hand, the HDAM file doesn’t have the separate index file, however, the key field of each record is competent a randomizer that places the record to a selected position within the information.

3. What is Mainframe Testing?

Answer:
Mainframe Testing is the testing of computer code services and applications supported by Mainframe Systems. Mainframe testing plays an energetic role in application development, overall development price and quality. Mainframe checking may be a part of end-to-end test coverage spanning platforms.

Mainframe Testing is sometimes performed on the deployed code victimization varied information combos set into the input data.
Applications that run on the mainframe are accessed through terminal somebody. The somebody is that the sole computer code that has to be put in on the shopper machine.
While activity Mainframe testing, the tester solely has to realize the navigations of the CICS screens. they’re custom-designed for specific applications.

4. What are the various attributes of Mainframe Computing?

Answer:
This is the basic Mainframe Interview Questions which are asked in an interview. Although several believe that mainframe computers square measure dinosaurs headed toward extinction, the massive corporations of the planet still run on mainframe computers. Below square measure the attributes that make mainframe computing scalable, stable and secure.

Virtual Storage

It’s a method that lets a processor simulate main storage that’s larger than the particular quantity of computer storage.
It uses disk storage as associate degree extension of computer storage.

Multiprogramming

The pc executes one program at a similar time.
It’s a facility provided to form economical use of the central processor.

Batch Processing

It’s a method that any task is accomplished in units called jobs.
Employment might cause one or additional programs to execute in a very sequence.
The mandatory data for execution is provided through JCL (JOB management LANGUAGE).

Time-Sharing

In a very time-sharing system, every user has access to the system through the terminal device. rather than submitting jobs that square measure regular for later execution, the user enters commands that square measure processed at once.

Spooling

Spooling stands for synchronic Peripheral Operations on-line.
It’s a facility exploiting the advantage of buffering to form economical use of the output devices.

5. What is the difference between static and dynamic SQL?

Answer:
In Stats SQL, the statement is ready before the program is dead and therefore the operational type of the statement persists on the far side the execution of the program. A program containing static SQL statements should be processed by associate degree SQL precompiles before it’s compiled.
A dynamic SQL statement is ready throughout the execution of associate degree SQL application, and therefore the operational type of the statement isn’t persistent. The supplied type of the statement may be a character string passed to DB2 victimization the static SQL statement PREPARE or EXECUTE IMMEDIATEly.

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Part 2 – Mainframe Interview Questions (Basic)

This second part covers Advanced Interview Questions and answers

6. How do you use EXPLAIN in DB2?

Answer:
When associate degree SQL is dead against or sure to a DB2 information DB2 Optimizer tool defines the access path accustomed access the info. This access path is outlined per tables’ statistics generated by DB2 Runstats tool. By victimization following manner, we are able to use just in DB2

Create an inspiration table
Run justify statement for the question with a question no (this inserts the info within the higher than setting up table)
Retrieve (select *) the info hold on within the setup table for the question no

7. What is the update cursor?

Answer:
An update pointer permits you to delete or update the present row; that’s, the foremost recently fetched the row. the aim of the keyword UPDATE in a very pointer is to let the information server apprehend that the program will update (or delete) any row that it fetches. The information server places an additional exacting lock on rows that square measure fetched through associate degree update pointer and a less exacting lock once it fetches a row for a pointer that’s not declared therewith keyword.

8. How is JCL used for testing batch programs?

Answer:
JCL is the management language for running programs in a very batch atmosphere. once running a check job, the JCL that truly controls the method is submitted as a check JOB.

Let us move to the next Mainframe Interview Questions

9. Does QTP Tool support Mainframe Application Testing?

Answer:
Yes, QTP Supports Mainframe Application Testing, it’s TE (Terminal Emulators) Add sure supporting Mainframe atmosphere.

10. Can you name few software running on the mainframe?

Answer:
IBM is the pioneer within the mainframe computing field. a number of their software square measure COBOL, Enterprise COBOL, JCL, VSAM, CICS, DB2, etc.
Other players within the market square measure Unisys (Clear path), Hitachi (zSeries), horsepower (Non-stop), and Fujitsu (BS2000/ ICL VME) amongst several others.