Selecting records with templates

When working with a data set in a panel or function, you can use a template to select the specific records that you want to use. You can specify two levels of criteria to select the records you want to process.
Record identification criteria
This identifies the unique characteristics of a record type, enabling Z Data Tools to distinguish it from other types of record in the same data set. By default, if you do not specify these criteria, Z Data Tools uses record length to identify a record type.

If the length of a record matches more than one record definition in the template, and no further record identification criteria are specified, Z Data Tools uses the first matching record type in the template to display all records.

Record selection criteria
After a record has been identified as belonging to a particular type, you can narrow down which records of that type you want to process by specifying record selection criteria.

You specify record identification criteria and record selection criteria using comparison expressions. When you specify criteria, you should be aware of the potential for incurring processing overheads as a result of invoking REXX to resolve the criteria expressions.

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