4.8.4 Batch Control Considerations
Once batch control is created between two files, it will be necessary to delete the batch control definition before attempting to delete either of the files being used.
It is important to note that batch control and file triggers work with the real fields in the file, whereas PJFs use virtual fields. Depending on the database design, one technique may have advantages over another.
Equivalent functionality to batch control can be performed using file level triggers. Though the trigger approach requires manual coding of the trigger functions, the ability to manually code the application logic makes the trigger very flexible and very powerful. Triggers are the recommended approach for implementing batch control type logic.
Predetermined join fields can also be used for calculating totals between files. When deciding if a PJF should be used instead of batch control, it is very important to note the difference in these two techniques. Batch control keeps a total in an existing real field in a file. The value is maintained when the dependent file is updated. With the PJF, the field is a virtual field. It is not part of the file. The PJF total is calculated when the field is accessed in the file.
Batch control is fully supported with RDML files. However, when used with RDMLX files, it will work only with RDML keys and target/source fields.