When the replica database propagates data to the master database, the master database is not required to accept that data. Within a master/replica system, only the master database has the authority to declare data to be official. If the master database receives data that violates database rules (such as referential integrity constraints), or business rules (such as prohibiting customers from exceeding a certain credit limit), the master database can reject or alter the data.

The master database also has other options to bring data into conformance, such as modifying the data. For example, if a customer orders more widgets than are in stock, the master database might modify the customer order so that the customer is sent all the remaining available widgets. In this way, the customer order is not completely canceled.

Advanced Replication includes the Intelligent Transaction feature that helps application developers to control the consistency of the master database. The Intelligent Transaction feature allows a transaction to validate itself in the master database and adjust its behavior to ensure the validity of the transaction, see Intelligent Transactions.