Distributed Database Management System: Advantages and Disadvantages

Distributed database management system (DDBMS) are databases which perform logical database activities from different interconnected computers with distribution operations in various sites (Coronel & Morris, 2016). In DDBMS the processing and storage of data are distributed logically over two or more independent physical computers connected over a network. DDBMS are different from the centralized database and other traditional database systems that store data in the same location where processing takes place.

The rapid improvement and innovation in the technology sector have led to the massive adoption of DDBMS. Today business and people are interacting daily at a global level thanks to the internet.  The use of DDBMS would be impossible if there were no World Wide Web as it offers the possibilities of connecting multiple database and people from different regions to access the same data at the same time. Another factor that has led to increased use of DDBMS by most business is the mobile wireless revolution. Scientific advancement has made it possible for people to walk with immense computing power capable of communicating with other devices at their pockets. As of 2014, many wireless devices are connected to the internet than there are humans in the world at 7.2 billion (Boren, 2014). Estimations indicate that two years from now more than 50 billion devices will be connected to the internet (Nordrum, 2016). People can use devices such as portable computers, smartphone, and tablets that can access distributed data.  All these devices are connected to the internet and to DDBMS which allow people to access data and information using their mobile devices despite their location. Social media is also another thing that has attributed to the adoption of DDBMS as various users upload media such as photos and videos which are to be stored in databases near them for quick access.

Advantages of Distributed Database Management System

The first advantage of DDBMS to traditional database systems is speed. Since there are different data centers in various geographical regions, one can access data from the nearest facility. As a result, access speed is higher because of the shorter distance of information transfer. Closely related to the benefits that come with reduced distance is the reduction in operating cost. Also, it is cheaper to add a new server than upgrading which requires replacing the existing infrastructure with more expensive ones as in the case of centralized database systems. In DDBMS cheap PC can be joined and their combine processing power be used to offer database service. On the other side, a centralized database will require the use of an expensive mainframe to allow it withstand high traffic that it may experience. 

DDBMS allow growth of the database system because it allows for the modular addition of other nodes. When an organization wants to expand its network they do not have do not have to worry about such actions affecting other operation as whereas in centralized DBMS additional of resource can prevent access to the database.

The design for DDBMS systems is meant to improve availability and reliability that is a challenge in centralized DBMS. The presence of multiple nodes each storing data ensures that access to the database is not affected even if one node goes down the others will be able to offer the same services. Also, it is impossible to strain one server with more workload as in case of high traffic, the excess traffic is directed to other nodes unlike in centralized DBMS that bears all the strain alone.  Multiple backups ensure availability of database services whereby even if one fails there is no disruption in service. 

Disadvantages of Distributed Database Management System

As pointed out earlier one of the advantages of DDBMS is that it improves consistency reliability and availability of database access. However, one cannot enjoy all those benefits concurrently. In 2000 Dr. Eric Brewer revealed that in highly distributed DBMS it is impossible for the system to provide consistency, availability and partition time simultaneously in what known as CAP theorem. Since it is not possible to experience the three desirable feature of a DDBMS at the same time this setback can limit the benefits noted earlier. As a result, most organization operate on a trade-off between consistency and availability.  This situation results in problems associated with data integrity whereby changes in data made in one node may not be reflected in others at the same time. To minimize the risks on compromising data integrity vendors have developed a new DDBMS design known as basically available, soft state, eventually, consistent (BASE) which ensures that changes on data are added slowly until every copy is consistent (Coronel & Morris, 2016).

Another disadvantage associated with DDBMS is the complexity of the system which is as a result of the coordination required for all the nodes to communicate concurrently. It is costly to implement the technology used to ensure high performance and other benefits that have resulted in this complexity. The issue of complexity also contributes to technological challenges of providing data integrity as observed earlier. The use of many nodes in DDBMS bring with it security risk as data breach at one site leads to the compromise of the whole system.

References

Boren, Z. (2014). There are officially more mobile devices than people in the world. Retrieved

from https://www.independent.co.uk/life-style/gadgets-and-tech/news/there-are-officially-more-mobile-devices-than-people-in-the-world-9780518.html

Brewer, E. A. (2000, July). Towards robust distributed systems. In PODC

(Vol. 7).

Coronel, C., & Morris, S. (2016). Database systems: design, implementation, & management.

Cengage Learning.

Nordrum, A. (2016, August 18). Popular Internet of Things Forecast of 50 Billion Devices by

2020 Is Outdated. Retrieved from https://spectrum.ieee.org/tech-talk/telecom/internet/popular-internet-of-things-forecast-of-50-billion-devices-by-2020-is-outdated