Skip to main content

Distributed Databases

Database is a huge collection of data. It lies in memory of a Computer. Several Databases may be present on different Computers at different locations. These Databases are called Distributed Databases. They may be within a small area. Such Databases may be across locations separated by large distances. 


A Distributed Database System controls several DBMSs. A DBMS controls a Database. This arrangement tells us how Databases are organized in a Distribution.

The topmost control authority is Distributed Database System. DBMSs are the subsystems. There are a number of DBMSs controlled by the Distributed Database System. These DBMSs contain Databases. A DBMS is in-charge of a  Database. We may say that a DBMS is a Database authority.  A DBMS and its Database exist together at a location.

____________________________

Note: DBMS ( DataBase Management System) is a program to develop a Database and help to use the Database.

___________________________

Distributed Databases are rich with information. Information that is part of Distributed Databases can be accessed easily. The manner of access is uniform. Data that is actually on different Computers is felt to be present on a single Computer. Distributed Database System is responsible for ensuring the comfortable feeling of existence of a single Computer where all the Databases are located.

A Database may be an integral part of the Distributed Database System. It is also possible that a Database is loosely attached to the Distributed Database System. In fact, the loosely attached Database is an object of a separate system.

The Databases may be designed using the same technology. Different technologies can also be used in the  design of Databases. When two Databases are designed using different technologies they have fundamental differences. 

Different Database designs require different ways to access data. There may be differences in the basic structure of Databases.

For data safety, we can make exact copies of data in databases that are part of Distributed Database System.




Labels:

Comments

Post a Comment

Popular posts from this blog

Interface Message Processor ( IMP )

Interface Message Processor ( IMP ) is a special purpose Computer. The Processor plays a vital role in Host-to-Host communication. IMP is placed between Host Computers.  IMP helps Hosts to exchange information. IMPs ( Interface Message Processors ) form a group. The group dedicates itself towards reliable transmission of Packets. _________________________ Note: An Interface Message Processor can be supposed to have a face. Firstly this supposed face of IMP is in the direction of the first Host, which sends the  message. Secondly, this face is turned towards the other Host.  Now, the IMP,  with its face turned around, communicates with this other Host.  Transformed message from IMP is communicated to this Host. __________________________ Message ( a piece of information ) sent from the Host ( source of information  ) is transformed into Packets. Transformation of the message into Packets is performed by an IMP. These Packets are forwarded to the receiver H...
Post a Comment
Read more

Understanding Distribution

Distributed presence means that more than one object is there. Also, these objects are situated at more than one location.  One object may establish communication with another object. The first object may deliver some message. The message can be received by another object. It can be said that object distribution is successful, as one object has succeeded in delivering a message. The second object has successfully received the message. Two objects are at a distance. Communication brings them closer. The successful communication has served to highlight that the idea of distribution is meaningful. Distribution helps exchange of information. Many different objects can form a group.  Two groups can occupy different locations.  It may happen that at a particular location there are several objects. But, all these objects talk among themselves.They talk among themselves and make things happen.  There is a resultant of this talk process. All the communicating objects  at...
Post a Comment
Read more

Message Switching

Message is a piece of information. Switching means movement.  In a Network there are a number of nodes. Nodes are vital junctions of a Network. Message Switching means transmission from one node ( one point ) of a Network to another node ( another point ). So, transmission is from point to point. Transmission from one point to another point is a single hop ( jump ). Message Switching means switch over of a Message. In one step of Message Switching,  Message switches over from one node to another.  The two nodes involved in a Switching operation are on the same Network. It cannot be that the beginning node ( source node) is on one Network and the second node ( sink node ) is on a different Network. In a point to point ( one junction to another junction ) transmission, a Message travels a part of its journey. Message moves from previous point to next point. The Network is Point-to-Point Network. A Switching activity means movement of a message. Indeed, the Message has mov...
Post a Comment
Read more