Oracle Distributed Systems

Differences Between Oracle7 and Oracle8

Oracle has added a wide variety of capabilities into the Oracle8 server. Some of the more significant enhancements relevant to distributed databases are highlighted here.

Global users and global roles

Oracle8 provides a user management scheme that supports maintenance of users and roles across multiple database instances. Instead of having to visit every instance to grant privileges, create users, and so on, you can define users and roles in such a way that changes from a central location take effect everywhere.

System security model

The management of users in an advanced replication environment is simplified tremendously in Oracle8, with the introduction of propagator and receiver accounts. Instead of having to create a user in all instances participating in the replication and having to create and verify private database links for each user, you can designate one account to queue DML and one account to apply DML.

Parallel propagation

Oracle8 is able to push replicated transactions either in parallel or serially. The replication option can determine which transactions are independent of one another so that transactional consistency is preserved. The net result is a significant improvement in throughput.

Reduced data propagation

With Oracle8 you can omit columns in a table from replication. What this means is that the replication facility does not check the before and after values of the columns that you so designate. Since these columns are not ...