Checking if a Job Should Run At All
Often, a job should only run if a certain test is passed. For example, an import task is to run subject to a condition, such as:
•The user must provide a suitable filename
•The file must not already have been imported
•A stock amount recorded in the database must be down to a certain maximum.
You can include such a test at the beginning of the batch job using various means, for instance:
•By using a table-base external set as input parameter set, and then defining constraints on this table that check the input parameter values.
•By calling the job from a decision.
If you insert a separate test at the beginning of the batch job, you get better performance if the job fails, and you avoid unnecessary messages in status files.