If a mapping includes a database target, you can select an existing target table or create the target table at run time. When you create a database target at run time,
Data Integration
automatically discovers the target object metadata for data type, precision, and scale, based on the data source.
If you need to edit target object metadata, you can edit it in the Source transformation.
You cannot link the target fields to the upstream transformation. If you want to reduce the number of unused fields in the target, configure field rules in the Target transformation or in the upstream transformations.
When you create a database target at run time, the
mapping
task creates the database table the first time the mapping runs based on the fields from the upstream transformation.
In subsequent runs, the
mapping
task replaces the data in the target table that was created in the initial run. Consequently, if you change the mapping after the initial run, in subsequent runs the target will not reflect changes to the number of target fields and its metadata. To see the changes, you can either delete the existing target before you run the mapping or change the name of the target.
If you create a relational target at run time, the target operation is always insert. You can choose to truncate the target.