Distributed Database Architecture

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Research project (databases)
2. Using the Internet or library resources, conduct some research on issues or problems related to distributed database architecture.

3. In a Microsoft Word document, write an 800- to 1,000-word research paper. Your research paper should contain the following sections in the order they are presented below:

Introduction
Scope of the issues or problems
Present research done to resolve the issues or problems
Solution that could be implemented in the future to solve the issues or problems
Conclusion
List of resources referenced

Introduction
A distributed database can be defined as a database that is housed in multiple storage locations all under the control of a central database management system. The data may be stored on multiple computers in a single physical location or they may be in multiple physical locations.

The database is partitioned into multiple fragments which can be replicated to multiple storage locations for redundancy.

The distributed nature of the database is hidden from users. A good example of a distributed database is Microsoft's Active Directory when implemented in a multi-server environment.

A distributed DBMS should provide a number of features which make the distributed nature of the DBMS transparent to the user. These include the following:
?Location transparency
?Replication transparency
?Performance transparency
?Transaction transparency
?Catalog transparency

The distributed database should appear as a single system to the end user.

From (Date, 1990):

"We begin with a working definition (necessarily a little imprecise at this point):
A distributed database system consists of a collection of sites, connected together via some kind of communications network, in which
1. Each site is a database system site in its own right, but
2. The sites have agreed to work together (if necessary). So that a user at any site can access data anywhere in the network exactly as if the data were all stored at the user's own site.
It follows that the so-called 'distributed database?is really a kind of virtual object, whose component parts are physically stored in a number of distinct 'real?databases at a number of distinct sites. In effect, it is the logical union of those real databases.?

"It is common to assume that the component sites are physically dispersed ?possibly in fact geographically dispersed also, ...although actually it is sufficient that they be dispersed logically. Two sites might even coexist on the same physical machine.
Scope
There are a number of advantages to using a distributed DBMS. These include the following:
?Capacity and incremental growth
?Reliability and availability
?Efficiency and flexibility
?Sharing

Capacity and growth
One advantage of a distributed database such as Active Directory is that as the organization grows, new distribution sites can be added with minimal impact to the database or the hardware environment. If a database is centralized, growth may require new hardware or increased storage in the central location.

Reliability and availability
An advantage of distributed databases is that even when a portion of a system (i.e. a local site) is down, the overall system remains ...