JOB Statement and its Parameters

    1.      What are the various parameters that are generally coded on JOB statement? Following are some of the parameters that are used on...

   1.     What are the various parameters that are generally coded on JOB statement?

Following are some of the parameters that are used on JOB statements.

Account, Name, Class, Region, COND, MSGCLASS, MSGLEVEL, TYPRUN, PRTY and Region etc. Out of these Account, Name parameters are Positional parameters and are mandatory and remaining are key word parameters.

   2.     Explain JOB statement.

Jobname, (acctnum,acctname) (positional parms),'Name' (positional parm), CLASS= , PRTY= , MSGCLASS= , MSGLEVEL= , TYPRUN= , NOTIFY= . CLASS and MSGCLASS can have one of the 36 values, A-Z and 0-9. Class depends on the amount of CPU time required and use of tapes by the job. MSGCLASS specifies the job scheduler message output class. TYPRUN can be SCAN or HOLD. PRTY is used to specify the priority of the job, smaller number indicates higher priority (allowed values are 0-15 for JES2 and 0-14 for JES3). MSGLEVEL have two positional parameters stmts, mesgs; Stmts of '0' indicates print only Job statements, '2'-print all JCL and JES statements and Messages, '3'-only JCL & JES statements print; Mesgs of '0' only JCL messages print; if the job ABENDs, then JES messages too, '1'- JCL and JES messages print. NOTIFY is used to notify the user about the completion of Job.

   3.     Can comments be started at any column in JCL statement?

Yes, they can be started after last operand in a JCL statement.

   4.     What is the difference between keyword and positional parameters?

Positional parameters are characterized by their position in the operand field in relation to other parameters.

Keyword parameters are positionally independent with respect to others of their type and consisting of a keyword followed by an equal sign and variable information.  

   5.     How many positional Parameters are there in a JOB statement?

There are TWO position parameters in a JOB statement.

   6.     What does CLASS parameter specifies?

Job Class identifies the nature of the job that is to be submitted. Some jobs can be short running, others can take a long time, still others may utilize heavy resources. The job class is used to identify these characteristics to the operating system.

   7.     What is the significance of TYPRUN parameter in JCL?

If TYPRUN=SCAN is coded, it checks job for syntactical errors.

If TYPRUN=HOLD is coded, holds the Job without running. This job can be run only after operator releases the Job.

   8.     What is the use PRTY parameter?

The PRTY parameter is related to the CLASS parameter. It assigns priority to jobs, which belong to same class.

   9.     What is the significance of Region Parameter on Job Card

To override the installation default Region size for executing your job, Region parameter will be used. REGION=0M parameter again allocates maximum space that is available in the system to execute the job.

10.     What is the parameter to be passed in the job card for the unlimited time, irrespective of the job class

TIME=1440

11.     What does the TIME parameter signify ? What does TIME=1440 mean ?

TIME parameter can be used to overcome S322 abends for programs that genuinely need more CPU time. TIME=1440 means no CPU time limit is to be applied to this step.

12.     How does the system determine the priority of a job for execution?

First the system determines which job has the highest class. Each class has a job queue with jobs of different priorities. The system will select the job for execution that has the highest PRTY (0 thru 15) 15 is the highest priority.   

13.     What is a MSGCLASS parameter?

It is a keyword parameter which specifies the output class to which system messages for your job are to be routed. Output class is an alphabetic (A thru Z) or numeric (0 thru 9) character. The default for MSGCLASS parameter will be System messages and output data sets can be routed to the same output class. You can code the MSGCLASS parameter in the Job statement and the SYSOUT parameter on the DD statement.

  

14.     What is MSGLEVEL parameter?

It is a keyword parameter which indicates what job output is to be written as a part of output listing. The following outputs can be requested: the Job statement;

all input job control statements;

allocation, disposition and allocation recovery messages(allocation/termination message)

MSGLEVEL=(statements, messages)

Statements:

- 0 - only the job statement is to be written;

- 1 - all input control statements, cataloged procedure statements and the internal representation of procedure statement parameters after symbolic parameters substitution are to be written

- 2 - only input job control statements are to be written;

Messages:

- 0 - No allocation/termination messages are to be printed unless the job terminates abnormally;

- 1 - All allocation/termination messages are to be printed. 

15.     How can you check for syntax or JCL errors without actual execution of a job?

TYPRUN=SCAN should be specified on a job card

16.     How do you Restart a step in JCL?

Using the RESTART=step name command in the Job statement you can restart the job from a particular step.