Use an active Custom transformation to set the update strategy for a mapping at the following levels:
Within the procedure.
You can write the external procedure code to set the update strategy for output rows. The external procedure can flag rows for insert, update, delete, or reject.
Within the mapping.
Use the Custom transformation in a mapping to flag rows for insert, update, delete, or reject. Select the Update Strategy Transformation property for the Custom transformation.
Within the session.
Configure the session to treat the source rows as data driven.
If you do not configure the Custom transformation to define the update strategy, or you do not configure the session as data driven, the Integration Service does not use the external procedure code to flag the output rows. Instead, when the Custom transformation is active, the Integration Service flags the output rows as insert. When the Custom transformation is passive, the Integration Service retains the row type. For example, when a row flagged for update enters a passive Custom transformation, the Integration Service maintains the row type and outputs the row as update.