Job Control Language does not support multithreading inherently. A method of accomplishment is implemented, known as redneck way, which forks other jobs into INTRDR. This is not risk free. There is an assumption that all the jobs would be finished prior to the next program that pulls in all data processed by other threads.
Another way of accomplishing multithreading is by using system enqueue and duplicate the job names. Use a scheduler that is able to schedule many jobs at once and leaves the next job when all the prereq’s have finished.
What is COBOL?
COBOL is abbreviated as Common Business Oriented Language and it is one of the oldest programming languages. It primarily used for business, finance and administrative systems for companies.
What do you understand by passing by reference and passing by content?
Passing by reference: When between programs data is shared or passed the subprogram always refers and processes the data items within the calling programs storage. It does not work on the copy of the data. Whenever a call by reference identifier is used the caller and the called share the same memory.
Passing by content: In this case the calling program only passes the contents of the identifier or the literal. When this is used the called program is unable to change the value of the identifier or the literal in the program being called. Further it cannot change the value even if it has modified the variable through which it received its literal.
Which division and paragraphs are mandatory for a COBOL program?
Identification division and Program ID are mandatory for a COBOL program.
Discuss about changing Dataset name in PROC.
Dataset name can be changed by overriding from the calling job. One of the ways of using JCL overriding is in the form of PROCSTEP.PROCDD DD DSN=[overriding dsn name]. This works pretty good, provided the same dataset is used for overriding.
Another method of overriding DSN is by changing the proc dsn to a variable. A “&” proc pram is used by this process. The benefit is enforcing a dsn passing. In case the default is left blank and not overridden the job would crash with DSNF.