Database Management System (DBMS)

Techopedia explains Database Management System (DBMS)

A database is the back-end of an application. A DBMS receives instruction from a DBA and accordingly instructs the system to make the necessary changes. These commands can be to load, retrieve or modify existing data from the system. A DBMS always provides data independence. Any change in storage mechanism and formats are performed without modifying the entire application .

There are four main types of database organization:

• Relational Database: Data is organized as logically independent tables. Relationships among tables are shown through shared data. The data in one table may reference similar data in other tables, which maintains the integrity of the links among them. This feature is referred to as referential integrity - an important concept in a relational database system. Operations such as select and join can be performed on these tables. This is the most widely used system of database organization.

• Flat Database: Data is organized in a single kind of record with a fixed number of fields. This database type encounters more errors due to the repetitive nature of data.

• Object Oriented Database: Data is organized with similarity to object oriented programming concepts. An object consists of data and methods, while classes group objects having similar data and methods.

• Hierarchical Database: Data is organized with hierarchical relationships. It becomes a complex network if the one-to-many relationship is violated.