Mainframe / JCL Interview Questions

Mainframe Interview Questions

Cobol | DB2 | JCL | JCL2 | VSAM | VSAM2

What is the purpose and meaning of the TIME keyword and what JCL statement is it associated with?

TIME specifies the maximum CPU time allocated for a particular job or job step. If TIME is in the JOB card, it relates to the entire job; if in the EXEC statement, it relates to the job step.

What is the meaning of data definition name (ddname) and dataset name (dsname) in the DD statement?

Data definition name is the eight character designation after the // of the DD statement. It matches the internal name specified in the steps executing program. In COBOL that's the name specified after the ASSIGN in the SELECT ASSIGN statement. Dataset name is the operating system (MVS) name for the file.

How is the keyword DUMMY used in JCL?

For an output file DUMMY specifies that the output is to be discarded. For input it specifies that the file is empty.

What does the keyword DCB mean and what are some of the keywords associated with it?

DCB stands for data control block; it is a keyword for the DD statement used to describe datasets. Keywords associated with it are BLKSIZE, DEN, LRECL and RECFM.

What is the difference between BLKSIZE and LRECL?

BLKSIZE specifies the number of bytes

Mainframe / JCL Interview Questions