A Database Management system abbreviated as DBMS is an important component of an environment in which business applications are provided with their required data from a database. In other words a computer based information system relying on database approach is incomplete without a DBMS. It is the main requirement of any database that is to be developed and implemented in an organization to handle its business activities. A DBMS can be defined as "A software application that is used to create, maintain and provide controlled access to user databases is called a database management system." A DBMS is thus responsible for finishing the dependency of database file and the program used for accessing data from it. Further it also keeps the actual data stored in database completely in isolation from the database structure.
A DBMS works on the basis of database management theory that eliminates dependence between database file and other data accessing programs. A DBMS is a sophisticated collection of programs that sets up storage structures, loads the data that it appears in the form in which the programs and users expect it to be. A DBMS also hides the data that a particular user should not have access to. In other words, it is responsible for providing security to data.
Different operations on data such as retrieval, updating, insertion and deletion are performed under the complete supervision of DBMS. Only those users are allowed to perform such operations on data who are authorized by the DBA to do so. The DBMS allows users to use data concurrently without being interfereed with each other. DBMS is also responsible for performing backup and recovery procedures automatically. In short, all of the profits that database possess over conventional file system are facilitated with the help of DBMS software, some common examples of DBMS are Oracle, Ingress, Informix, MySql, and Microsoft SQL server, etc.
The main characteristics of DBMS are given below
A DBMS representations complex relationships between data.
A DBMS keeps a tight control of data redundancy.
A DBMS endorses user-defined rules to ensure the integrity of table data.
It ensures that data can be shared across applications.
It enforces data access authorization.
It has automatic, intelligent backup and recovery procedures for data.
Types of DBMS
There are three main types of DBMS and these types are based upon their management of database structures. In other words, the types of DBMS are entirely dependent upon how the database is structured by that particular DBMS. The following are the three types of DBMS.
1. Hierarchical DBMS
2. Network DMBS
3. Relational DBMS