21.What is a JCL?
JCL stands for Job Control Language which provides the specifications necessary to process a job. It is a set of control statements which provides the specifications necessary to process a job. It is a interface between programs & MVS operating system.
22.What does MVS stand for?
MVS stands for Multiple Virtual storage which is the operating system for the IBM mainframe systems.
23.Where & how do you code Identifier in JCL?
Identifiers are two slashes (//) starting from column number 1. All JCL statements starts with identifiers except for two exceptions – For a delimiter statement, /* starting in col 1 and for a comment statement , //* starting at col 1.
24.What are the various stages of Job processing?
Input −> Conversion −> Execution −> Output −> Hard copy −> Purge
25.In Job processing, what happens in Conversion stage?
The JCL along with the PROC is converted into an interpreted text to be understood by JES and stored into a dataset, which we call as SPOOL.
26.In Job processing, what happens in Execution stage?
When the job reaches its highest priority, it is taken up for execution from the job queue. The JCL is read from the SPOOL, the program is executed and the output is redirected to the corresponding output destination as specified in the JCL.
27.What operation is performed by JOB statement?
Specifies the information required for SPOOLing of the job such as job id, priority of execution, user-id to be notified upon completion of the job.
28.How do you code a Null statement?
JCL is terminated by a null statement which is optional. For a null statement code only // starting from column 1. All the lines after this will not be executed.
29.What is the purpose of coding CLASS parameter in job statement?
Based on the time duration and the number of resources required by the job, companies assign different job classes. These can be visualized as individual schedulers used by the OS to receive the jobs. Placing the jobs in the right scheduler will aid in easy execution of the jobs. Some companies have different classes for jobs in test and production environment. Valid values for CLASS parameter are A to Z characters and 0 to 9 numeric (of length 1). Following is the syntax − CLASS=0 to 9 | A to Z
30.What is the purpose of coding NOTIFY parameter in job statement?
The system sends the success or failure message (Maximum Condition Code) to the user specified in this parameter. Syntax − NOTIFY = “userid | &SYSUID”