When client applications or application servers work with a single transaction processing database, such as SQL Anywhere, there is no need for transaction logic outside the database itself, but when working with multiple resource managers, transaction control must span the resources involved in the transaction. Application servers provide transaction logic to their client applications—guaranteeing that sets of operations are executed atomically.

Many transaction servers, including Sybase EAServer, use the Microsoft Distributed Transaction Coordinator (DTC) to provide transaction services to their client applications. DTC uses OLE transactions, which in turn use the two-phase commit protocol to coordinate transactions involving multiple resource managers. You must have DTC installed to use the features described in this chapter.

SQL Anywhere in distributed transactions

SQL Anywhere can take part in transactions coordinated by DTC, which means that you can use SQL Anywhere databases in distributed transactions using a transaction server such as Sybase EAServer or Microsoft Transaction Server. You can also use DTC directly in your applications to coordinate transactions across multiple resource managers.