What is a distributed database?

A distributed database is the one where all the storage devices are not attached to a common CPU (central processing unit). It may be distributed over a network of interconnected computers, or it may be stored in multiple computers located in the same physical location.

Distributed Database Management System

  • A distributed database management system (DDBMS) manages the database as in if it is stored in the same computer.

  • The DDBMS synchronizes all the data in a periodical manner and in situations when multiple users are accessing the same data and ensures that updation and deletion performed on the data at one location shall be automatically updated in the data stored elsewhere.

  • The users and administrators of the distributed system, with proper implementation, interact with the system as if the system is centralized.

  • This transparency allows the functionality desired for a structured system without specially programmed requirements allowing for any number of local or remote tables to be accessed at a given time across the network.

  • The different types of transparency of DDBMS are data distribution transparency, heterogeneity transparency, transaction transparency, and performance transparency.

Data distribution transparency, requires that the user of the database must not know how the data is fragmented, know the location of data, or be aware of whether multiple copies of the data exist.

In heterogeneity transparency, the user shall not be aware of the fact that they are using a different DBMS if they access data from a remote site. The user is able to use the same language that they would normally use at a regular access point and the DDBMS should handle query language translation if needed.

In transaction transparency, the DDBMS guarantees that concurrent transactions do not interfere and that it must also handle database recovery.

Performance transparency mandates the DDBMS that has a comparable level of performance to a centralized DBMS. Query optimizers are used to speed up response time.


The advantages of distributed database management system over centralized system are explained below −

  • It shows organizational structure.

  • Ability to share is increased.

  • Availability is improved.

  • Performance is increased.

  • Workstations are located nearest to the greatest demand site so that migration cost is reduced.

  • Data Access for users is faster.

  • Reliability is improved.

  • Here, data is processed at several different sites. So, faster data processing is possible.

  • In DBMS local sites are smaller and closer to customers therefore it improves the communication.

  • Operating cost is reduced.

  • Easy-to-use graphical user interface (GUI) which imparts user friendly interface.

  • Less chances of single-point failure because data and workload are distributed among other workstations.

  • The end user here is able to access any available copy of data.

Updated on: 08-Jul-2021


Kickstart Your Career

Get certified by completing the course

Get Started