An active transformation can perform any of the following actions:
Change the number of rows that pass through the transformation.
For example, the Filter transformation is active because it removes rows that do not meet the filter condition. All multi-group transformations are active because they might change the number of rows that pass through the transformation.
Change the transaction boundary.
For example, the Transaction Control transformation is active because it defines a commit or roll back transaction based on an expression evaluated for each row.
Change the row type.
For example, the Update Strategy transformation is active because it flags rows for insert, delete, update, or reject.
The Designer does not allow you to connect multiple active transformations or an active and a passive transformation to the same downstream transformation or transformation input group because the Integration Service may not be able to concatenate the rows passed by active transformations. For example, one branch in a mapping contains an Update Strategy transformation that flags a row for delete. Another branch contains an Update Strategy transformation that flags a row for insert. If you connect these transformations to a single transformation input group, the Integration Service cannot combine the delete and insert operations for the row.
The Sequence Generator transformation is an exception to the rule. The Designer does allow you to connect a Sequence Generator transformation and an active transformation to the same downstream transformation or transformation input group. A Sequence Generator transformation does not receive data. It generates unique numeric values. As a result, the Integration Service does not encounter problems concatenating rows passed by a Sequence Generator transformation and an active transformation.