JCL interview questions

JCL Interview Questions

  • ·        What is the difference between primary and secondary allocations for a dataset?

Ans:-Secondary allocation is used when more space is required than what has already been allocated by primary.

  • ·        How to access a file that had a disposition of KEEP?

Ans:-Since the file is not in catalog you will need to specify the volume serial no. VOL=SER=xxxx.

  • ·        What is DISP=(NEW,PASS,DELETE)?

Ans:- First disp of New means that it is a new dataset and needs to be allocated

  Second disp(Normal disposition) of PASS means that the dataset is to be passed to the next step if the step is successful

  Third disp (Abnormal Disposition) of DELETE is to Delete the dataset if the step abends.

Ans:-S0C7 abend is caused by invalid data in a numeric field.

Ans:- S0C7 abend is Storage violation error – can be due to various reasons. e.g.: READING a file that is not open, invalid address referenced due to subscript error.

  • ·         What does a disposition of (NEW,CATLG,KEEP) for a DSN mean?

Ans:- First disp of New means that it is a new dataset and needs to be allocated

  Second disp(Normal disposition) of CATLG means that the dataset is to be cataloged if the step is successful

  Third disp (Abnormal Disposition) of KEEP is to Keep the dataset and not catalog if the step abends.

  • ·        What are SD37, SB37, SE37 abends?

Ans:-All these abends are related to dataset out of space.

SD37 – This will occur if no secondary allocation was specified.

SB37 –  This abend signifies the end of vol. and no further volumes specified. 

SE37 – This abend comes if Max. of 16 extents already allocated.

Ans:- COND=EVEN is used to execute the current step even if any of the previous steps, terminated abnormally.

Ans:- COND=ONLY is used to execute this step only if any of the previous steps, terminated abnormally.

  • ·        How to check the syntax of a JCL without running it?

Ans:-We can use TYPERUN=SCAN on the JOB card

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  • ·        If we have multiple jobs (JCLs with several JOB cards) in a member.  What happens if we submit it?

Ans:-Multiple jobs will be submitted (as many jobs as the number of JOB cards).

  • ·        What is STEPLIB, JOBLIB?  What is it used for?

Ans:- Steplib and Joblib are used to specify the library  to be searched before the default system libraries in order to locate a program to be executed by the step or steps. STEPLIB is applicable only to the particular step while  JOBLIB is applicable to all steps in the job.

  • ·        What happens if both JOBLIB & STEPLIB is specified?

Ans:-Steplib is used.

  • ·        How many extents are possible for a sequential file and for how may for a VSAM file?

Ans:- For sequential file its 16 extents on a volume and 123 for a VSAM file.

  • ·        Can we code instream data in a PROC?

Ans:- No.

  • ·        Is it possible to pass instream data in a PROC?

Ans:- We can not code instream data in a PROC but its possible to code SYSIN DD DUMMY in the PROC, and then override this from the JCL with instream data.