Data Transformation Engine Type Designer Reference Guide

Chapter 8 - Components Component Attributes
Identifier Attribute
The identifier attribute can be used on a component of a group. The identifier
indicates the components that can be used to identify the type to which a data
object belongs. All the components, from the first, up to and including the
component with the identifier attribute, are used for type identification.
When this data is validated, it knows that, when it reaches the identifier, it has
found a specific group. That group, therefore, is known to exist, even if part of the
group following the identifier is missing. The Map Designer Reference Guide
discusses how data validation occurs.
The identifier attribute is also useful when identifying an object of a partitioned
group. For information about using an identifier with partitioned data, see
Chapter 9 - Partitioning.
Note In a component list, there can be only one identifier attribute.
Restart Attribute
To continue processing your input data when a data object of a component is
invalid, assign the restart attribute
to that component.
Note Do not put the restart attribute on a required component. There must be a
sufficient number of valid instances to cover all the required components. If you
have a required component, that is not valid, the restart attribute will not validate
the data.
For more information on the restart attribute, see Chapter 12 - Error Detection
and Recovery.
Sized Attribute
The sized attribute is used on a component in which the value specifies the
size (in bytes) of the component immediately following it. The sized attribute can
be used on more than one component of a group.
For example, you may have a variable length component with a number
immediately preceding it that indicates the length of the component: