You can add a Sequence Generator transformation before the Normalizer transformation in a mapping. The Sequence Generator transformation adds a sequence number to each source row. When the Normalizer transformation returns multiple output groups or rows from the same source row, each output row receives the same sequence number. You can use the number as a key in a primary key-foreign key relationship between target tables.

For example, the Normalizer transformation returns customer information in an output group and it returns order information in another output group. You can use the sequence number to link the customer information in a table to the order information in another table.