- What are the advantages of Mainframe Computers? …
- Where is the Mainframe technology used? …
- Expand DRDA. …
- What are the disadvantages of Mainframe technology? …
- What is SPOOL? …
- What is the difference between supercomputers and mainframes? …
- Expand SPUFI. …
- Expand QMF.
2) If any job abended in production support what are the steps you will take to resolve?
3) Assume if any job abened in payment cycle at particular record. How will you identity the record on with the job has abened?
Set of results returned by the SP after processing data retrieved from different tables as per business requirement.
Batch programs written in host language like COBOL are independent programs and are not stored as part of Database. Batch programs makes calls to DB2 to retrieve or update information. A predefined access path is generated while compiling and binding a batch program.
DB2 Stored Procedures are stored as part of Database. Application program calling DB2 Stored Procedure will make only one call and whole Stored Procedure will execute on the DB2 Server. This way we can prevent multiple calls to DB2 which causes network traffic and multiple authentication check.
7) What is the difference between static and dynamic SQL? Explain the compilation steps and advantage and disadvantages of static and dynamic SQLs?
In Stats SQL, the statement is prepared before the program is executed and the operational form of the statement persists beyond the execution of the program. A source program containing static SQL statements must be processed by an SQL precompiler before it is compiled. The precompiler checks the syntax of the SQL statements, turns them into host language comments, and generates host language statements to invoke DB2.
A dynamic SQL statement is prepared during the execution of an SQL application, and the operational form of the statement is not persistent. The source form of the statement is a character string passed to DB2 by an application program using the static SQL statement PREPARE or EXECUTE IMMEDIATE.
An index is a database table which contains the key fields value and their location (address) in the table. Index improves the speed at which we do operations on the table.
When an SQL is executed against or bound to a DB2 database DB2 Optimizer tool defines the access path used to access the data. This access path is defined according to tables’ statistics generated by DB2 Runstats tool.
Array are called as cobol tables and we can’t have table more than 7×7 in cobol.
When we do commit for the cursor, the cursor will not get closed and all the locks will be released on the tables in the cursor for all the rows except for the ones in current cursor. LOB locators will be freed.
An update cursor permits you to delete or update the current row; that is, the most recently fetched row. The purpose of the keyword UPDATE in a cursor is to let the database server know that the program can update (or delete) any row that it fetches. The database server places a more demanding lock on rows that are fetched through an update cursor and a less demanding lock when it fetches a row for a cursor that is not declared with that keyword.
15) Assume, in case of GDG we have created (+1) version in STEP1 and (+2) in STEP2 and we have to use STEP1 created GDG in STEP3 how will you use? Also If job abend at step2 how do use the GDG created in STEP1 and 2?
Use (+1) only in step3 as the version number in the catalogue gets update only after finishing the job or step(if job abends after the step).
Case 1: job not abended then 26 will get created in step1 and 27 will be created in step2 and we use (+1) in step 3 to refer the version created in step1.
Case 2: Job abended at after step2, then two versions will be created one in step1 and one in step2 . After restarting we need to refer (-1) in step3 if we need to refer the version created in step1.
16) After using indexes and writing the query with maximum possible options to achieve best performance but still the query is slow what will you do?
17) What is contention in DB2? Have you come across this kind of issues if yes, how do you resolve the issue?
18) If a cobol program what to retrieve 500 rows at a time and print it. And the database contain >1500 rows what logic you will use to retrieve the rows and to print?
21) How do you know that there are indexes in the table column after looking at the query (w/o using any tools)?
(Try to go into functional overview than technical one, As if you go into technical aspects much than functional then they will start asking you questions there itself.)
There is nothing special code as it is almost like a batch module. We need to define a temporary table if we are retrieving data from multiple tables and we declare a cursor on that table with return. This cursor will return the result set that this sp needs to return.
29) Why do you define Stored procedure with ‘WITH HOLD and WITH RETURN FOR’ oprion??Are they mandatory??
From any client or application we’ll pass all the input parameters and make position to accept the output variables or output result set returned by the SP.
31) How many SPs that you worked on??Client is expecting the programs that you actually coded.
No, we have the habit of having commit in calling programs rather than called programs. As its upto calling programs choice when and where to commit.
We pass the data to SP via input parameters and get the data via output parameters and output result sets.
We use DB2 development center to execute the SP. Again we have a GUI on which we can filter the all the sp we have in our DB . Select a SP and click on it , it’ll throw a pop for input parameters and throws output parameters and result sets. The second way is via DB2 development centers command prompt.
41) Some questions on MQ series, like what are MQI calls, and what if the SP fails then what will happen to the data in the Queue??
Even after reading in destructive reading from MQ the message will not get deleted from MQ until we force a COMMIT.
Mainframe Interview Questions and Answers for Experienced (more than 1 years) COBOL JCL DB2 | Learn
In-depth mainframe questions
While prior experience is valuable, a hiring manager will likely be most interested in your ability to demonstrate your technical skills and knowledge. The following in-depth questions can help you prepare for your interview:
As you can see, this line of questioning delves into specifics, giving the interviewer a chance to see how you think and communicate about processes while also testing your knowledge. Here are some more in-depth questions you may encounter:
Read more: Learn About Being a Database Administrator
What are foreign keys and what is their effect and use within a table?
Foreign keys are an important topic to understand when working in mainframes due to their ability to connect different tables together. When answering the question, you should be as concise as possible, demonstrating your understanding of the concept. Be sure to make note of foreign keys importance and usefulness when responding to the question.
Example: “A foreign key is a method of creating a relationship between two different tables on a mainframe computer. Foreign keys refer to a segment of one table that directly corresponds to the primary keys on a second table. This then identifies the items with each foreign key as bonded with the corresponding item identified with the primary key on the other table. This can be useful when working with complex datasets that are stored across multiple different tables.”
Questions about mainframe background and experience
One way that an applicant can demonstrate value to a potential employer is by having a proven track record of working on mainframes in a professional capacity. The following questions are commonly used to gauge background and experience:
Read more: 15 Computer Science Jobs That Pay Well
Before you go! Take this “Mainframe Interview Questions” interview guide with you
The mainframe ecosystem consists of computers having different combinations of processors and memory and act as workstations and terminals for processing jobs and performing required operations. The first mainframe computer was developed in the 1930s and was made ready to use in 1943. It weighed about 5 tonnes and filled an entire room and cost about $200K. IBM began developing smaller, Linux-based systems starting in 1998. Nowadays, Mainframe computers are known to be powerful, agile and are no less than the size of refrigerators. They are mostly used for data processing and data analysis that is capable of processing trillions of instructions per second. Due to the powerful processing capabilities, the need for mainframe developers is still in demand even though it is has gained the status of legacy technology.
In this section, we will see what are the most commonly asked mainframe interview questions covering concepts on COBOL as well as JCL that will help developers crack mainframe interviews. Crack your next tech interview with confidence! Take a free mock interview, get instant⚡️ feedback and recommendation
Top 5 Frequently Asked Mainframe Interview Questions
DRDA means Distributed Relational Database Architecture. It is a connection protocol that is used for local database processing. IBM and other vendor databases use it. It contains a set of rules which is used for communication between an application and a DBMS distant relation.
Are you prepared in attending an interview? We’ve a right answer for your job interview preparation. If you are preparing for IBM Mainframe job interview and clueless regarding the kind of questions to be asked in job interviews then go through Wisdomjobs IBM Mainframe interview questions and answers page to easily go through the interview process. IBM Mainframe are the computer systems that is widely used in earlier years. Later it got changed to Mainframe. COBOL, Pascal, FORTRAN are few mainframe programming languages. These are used for development of the basic design of the IBM Systems. Below is the list of frequently asked IBM Mainframe interview questions and answers which gets you ready to face the interviews with lot of confidence:
FAQ
Why you choose mainframe?
What is a bolt dispute in mainframe?
What are mainframe technologies?
Is mainframe a good career option?
