Distributed Database Systems Autonomy Oracle Tips by Burleson Consulting

The Data Warehouse Development Life Cycle

Distributed Oracle Data Warehouses

A Definition Of Distributed Databases

There is an ongoing debate over the standard definition of distributed database systems, and to muddy the waters further, vendors have implemented distributed database technology in different manners. To many database vendors, a distributed database is a geographically distributed system composed entirely of one brand of database products. On the other hand, front end applications vendors define a distributed database as a system distributed architecturally, using a blend of database products and access methods. Finally, to hardware vendors, a distributed database is a system composed of different databases running on the same hardware platforms.

So, the question remains--What is a distributed database? The most widely accepted, general definition of distributed databases was developed by Chris J. Date, the popular author and co-inventor of the relational database model. In his definition, Chris Date defined the following 12 characteristics of a distributed database.

* Local autonomy

* No reliance on a central site

* Continuous operation

* Location independence

* Fragmentation independence

* Replication independence

* Distributed query processing

* Distributed transaction management (update processing)

* Hardware independence

* Operating system independence

* Network independence

* Database independence

A distributed database contains all 12 of the characteristics named by Chris Date. Let’s take a look at each characteristic.

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This is an excerpt from "High Performance Data Warehousing", copyright 1997.

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