When you create a mapping with a Lookup transformation that uses a dynamic lookup cache, you must use Update Strategy transformations to flag the rows for the target tables. When you configure a session using Update Strategy transformations and a dynamic lookup cache, you must define certain session properties.
You must define the Treat Source Rows As option as Data Driven. Specify this option on the Properties tab in the session properties.
You must also define the following update strategy target table options:
These update strategy target table options ensure that the Integration Service updates rows marked for update and inserts rows marked for insert.
If you do not choose Data Driven, the Integration Service flags all rows for the database operation you specify in the Treat Source Rows As option and does not use the Update Strategy transformations in the mapping to flag the rows. The Integration Service does not insert and update the correct rows. If you do not choose Update as Update, the Integration Service does not correctly update the rows flagged for update in the target table. As a result, the lookup cache and target table might become unsynchronized.