Source tables and primary keys

The CDC Replication Engine for Microsoft SQL Server supports replication of data from a table without a primary key.

Replicating data in a table without a primary key will cause all the changed row data to be logged to a table in the SQL Server database. Depending on circumstances, this can result in a dramatic performance decrease and so should be undertaken with appropriate caution. Consult your Microsoft SQL Server documentation for further details on how the Change Data Capture feature is implemented and its likely performance impact on your database.