Any organization that uses the Oracle relational database management system (RDBMS) these days needs to use multiple databases. There are many reasons to use more than a single database in a distributed database system: Different databases may be associated with particular business functions, such as manufacturing or human resources. Databases may be aligned with geographical boundaries, such as a behemoth database at a headquarters site and smaller databases at regional offices. Two different databases may be required to access the same data in different ways, such as an order entry database whose transactions are aggregated and analyzed in a data warehouse. A busy Internet commerce site may create multiple copies of the same database to attain horizontal scalability. A copy of a production database may be created to serve as a development test bed. Tunability Platform autonomy Fault tolerance Scalability Location transparency Site autonomy Introduction to Distributed Database Systems SQL*Net and Net8 Configuration and Administration Distributed Database Security Designing the Distributed System Oracle's Distributed System Implementation Sample Configurations 8. Engineering Considerations Oracle Replication Architecture Advanced Replication Option Installation Basic Replication Multi-Master Replication Updateable Snapshots Procedural Replication Conflict Avoidance and Resolution Techniques In a distributed database environment, data in two or more databases is accessible as if it were in a single database. Usually, the different databases are on different servers, which may be located at the same site or a continent away. Communication between the servers takes place via SQL*Net (for Oracle7) or Net8 (for Oracle8). Distributed database environments offer a number of benefits over single- database systems, including: This book describes how you can use multiple databases and the distributed features of Oracle to best advantage. It covers: Table of contents: Part I: The Distributed System Part II: Replication Part III: Appendixes Appendix A: Built-in Packages for Distributed Systems Appendix B: Scripts