Oracle Distributed Systems

Chapter 6. Oracle’s Distributed System Implementation

Oracle has gone to some lengths to ensure that their RDBMS product meets Chris Date’s objectives for a distributed database system, which we described in Chapter 5. This chapter examines how Oracle networking and RDBMS products have addressed each of these objectives and discusses techniques you can utilize to achieve these goals in your own environment. I’ll also look at the inherent limitations and even contradictions in realizing these goals.

Meeting the 12 Objectives with Oracle

To review, the 12 objectives for a successful distributed database system, which we discussed in Chapter 5, are:

1. Local autonomy

2. No reliance on a single site

3. Continuous operation

4. Location transparency

5. Fragmentation independence

6. Replication independence

7. Distributed query processing

8. Distributed transaction management

9. Hardware independence

10. Operating system independence

11. Network independence

12. RDBMS independence

As I said in Chapter 5, these are goals, not requirements. We cannot, for example, reasonably expect a distributed database system to provide continuous operation in perpetuity. Nevertheless, the architects of the Oracle RDBMS have answered each of these goals, as described in the following sections.

Local Autonomy

Local autonomy requires that an individual database be fully functional even if it cannot contact other systems in the distributed environment and that each site be responsible for its own data integrity, security, and management. Unfortunately, it is ...