Data Transformation Engine Type Designer Reference Guide

Chapter 12 - Error Detection and Recovery Error Recovery
Error Recovery
You may want to map your data even when invalid data is encountered. For
example, you have a file of records and if some of the records are invalid, that is
fine. You do not want to stop; you want to go on and process all the valid records.
Restart Attribute
The restart attribute provides instructions for handling errors encountered in a
data stream.
The restart attribute may be assigned to a component. It applies when data is
validated - input data is validated as the first step in the mapping process. When
output data is audited by using Audit Settings in the Map Designer, output data is
also validated.
If you are mapping data of a component with a restart attribute only the valid
occurrences of that component are mapped. For example, suppose your input is a
file of records, and the Record component of File has the restart attribute.
Suppose some of the records are invalid. When you map the Record objects, only
the valid records are mapped. To map the invalid records (for example, to an error
file) use the
REJECT function.
For information on the
REJECT function, see the Functions and Expressions
Reference Guide.
Typically, you would assign the restart attribute to a component that has a series
range. For example, (1:20) or (s) and the objects in the series are independent of
one another. For example, if each record in your file is independent from the
others, it makes sense to ignore an error if it encounters an invalid one. A bad
record does not make the next record meaningless. But suppose the records are
related. Maybe they are records related to one purchase order; if any record is
bad, you want to stop after validation because it is important to have all records.
Losing any records would make the overall data incomplete.
To assign the Restart attribute to a component
1 Select the component.
2 From the Component menu, choose Restart.
Or, click
(Restart).