JCL Interview Questions. |
Welcome back to today's JCL Interview Questions session. In this session, you'll go through the top 10 JCL Interview Questions. These questions focus on generation data groups (GDG), VSAM, and other JCL tricks. These JCL interview questions are a quick refresher for both experience and freshers. Let's get started with JCL interview questions with answers.
Introduction to JCL.
The term JCL stands for Job Control Language. It's the command language of the z/OS operating system and it provides information related to the program and the datasets. JCL has three types of control statements i.e. JOB Control statement, Execute Statement, and DD statements.
Now, let's go through the top 10 JCL interview questions.
How is the JOBLIB is different from the STEPLIB statements in JCL?
In JCLs, the JOBLIB statement is specified immediately after the JOB statement (i.e. JOB CARD). JOBLIB is applicable for all steps in JCL. You cannot use JOBLIB in a cataloged procedure.
The STEPLIB statement in JCL's is generally specified immediately after the EXEC statement. JCL STEPLIB statement is effective for that job step and you can use STEPLIB in JCL cataloged procedures.
Important point - If you specify JOBLIB and STEPLIB in the mainframe job (JCL), then precedence would be given to STEPLIB.
Can you define the term GDG?
The term GDG stands for Generation Data Group. A GDG is a group of chronologically related datasets/files. The Generation Data Sets (GDG) are generally used for storing backups. You can use +0 to refer current generation dataset, +1 to create a new generation dataset, and -1 to refer previous generation dataset.
What are the different types of control statements in JCL?
Job control language has the following type of control statements:
- JOB Control Statement (JOB CARD).
- Execute Control Statement (EXEC Statements).
- DD Control Statements (DD Statements).
Let say the mainframe job (JCL) has five different steps to calculate monthly tax. The job failed at the second step. Now, how to restart the job from the second step or How to restart a job from the abend step?
The JCL RESTART parameter is used to restart the job from a specific statement. JCL restart parameter is an optional keyword parameter. You can use the JCL RESTART parameter to designate the proc step, checkpoint, JCL step, at which the system has to restart a job.
What is conditional processing of JCL?
Conditional processing in JCL is a technique through which you can skip or execute steps in a JCL. The ‘COND’ parameter is generally used in JCL for conditional processing. You use the "JCL COND" parameter on both the JOB control statement or Executec control statement. The syntax of JCL COND parameters is:
COND[.procstepname] = ((code,operator[,stepname][.procstepname])
COND=EVEN
COND=ONLY
Can you explain the disposition of (NEW, CATLG, DELETE)?
In JCL, the disposition parameter is a keyword parameter. It is used to specify the status of the datasets. JCL Disposition indicates to the system what to do with the data-set in case the job fails or is completed.
For Example: //STEP01 DD DSN=TPRP.TEMP.TAX.FILE,DISP=SHR
The monthly tax calculation job (i.e. JCL) abended with SD37. What would be the possible fix?
The Abend SD37 indicates that the dataset is out of space. The abend indicates that all of the primary allocated space has been used up and there is not any secondary space in the allocation to continue to write the file out. You should allocate more space and restart the job after carefully investigating the jobs.
What is the significance of the REGION parameter in a JCL?
The REGION parameter in JCL is generally used to override the REGION specified in the JOB card. You can use to specify the REGION parameter to specify the max region size i.e. REGION=0K, or 0M.
What is the significance of JCL COND=EVEN?
JCL COND parameter is used for the conditional processing of the JCL. COND=EVEN parameter executes the step even if any of the previous steps terminated abnormally.
What is the significance of JCL COND=ONLY?
JCL COND parameter is used for the conditional processing of the JCL. COND=ONLY parameter executes the step only if any of the previous steps, terminated abnormally.
JCL Interview Question - Youtube video!
Conclusion.
Finally, this marks an end to today's JCL Interview Questions. These JCL interview questions with answers are applicable for fresher and experienced. Please do check out more JCL tutorials on our blog.►Subscribe to Topictrick & Don't forget to press THE BELL ICON to never miss any updates. Also, Please visit mention the link below to stay connected with Topictrick and the Mainframe forum on -
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