Generation extensions

Once you select the annotate option in the wizard, the generation component determines the delta between the current selection of specifications and the last entry of the history information related to the targeted DataStage job.

The delta determination compares the values in each object with the last update information for each mapping in the current specifications (including the previous history information of the mapping). The delta determination checks for changes in any of the objects.

After the mappings are compared, an action flag is determined:

history.mapping: previous mapping of a history specification
current.mapping: most recent mapping of the current specification
- Update: history.mapping.id = current.mapping.id and history.mapping.ts < current.mapping.ts
- New: No history.mapping.id exists for a current.mapping id
- Delete: No current.mapping.id exists for a history.mapping.id
- Duplicate: Several history.mapping.ids are found for a given current.mapping.id

The delta provides the following information about column mappings:

Mapping ID
Action Flag
Source Field, Target Field, Transformation, Business Rule
Last Update Time Stamp
Last Update Description
Editor
Status

For other objects, such as joins, filters, switches, aggregates, and lookups, the delta provides information based on the values of their fields.

The delta information is transformed into DataStage canvas annotations and included into a DataStage local container, which is then placed on the DataStage job canvas of the related DataStage job.