What is a Database Management System
Database contains collection of interrelated data. It is a set of programs to access the data. Database Management System (DBMS) is a program that allows one or more computer users to create and access data in a database. Database Management System contains information about a particular enterprise. Database Management System provides an environment that is both convenient and efficient to use.
The fields where database is used are:
Banking: used in keeping record of the transactions Airlines: used in reservations, maintaining schedules Universities: used in keeping records of registration and grades of the students. Sales: used in customers, products, purchases Manufacturing and Human resources: for example: used for employee records, salaries etc…
In early days, database applications were built on top of file system but have now changed because of the disadvantages of the file systems to store data. Some of the problems were of data redundancy, duplication of information, difficulty in accessing data, data isolation etc…
Database Management System contains information about collection of interrelated data, set of programs to access the data. Database languages are:
DDL – Data definition Language DML – Data manipulation Language DCL – Data Control Language
Types of Database Management System are:
File System based Database Management System – it is simple but is inefficient and has very few capabilities. Hierarchical Database Management System – in this, the data is presented in the form of parent child relationship. For e.g. – geographical images. Network Database Management System – it is very flexible but is not widely used now- a- days. Relational Database Management System – It is a mature system and is widely used today, it is table oriented and has a restricted range of structures. A newer kind of Database Management System is the Object Oriented Database Management System (ODBMS) – it is developing, it has diverse structures and is extensible.
A Database Management System is an inherent part of a database product. For e.g. – Microsoft’s SQL Server is an example of Database Management System that serves database requests from multiple users. Some of the popular Database Management Systems are IBM’s DB2, Oracle’s products etc…
The advantages of a Database Management System include its additional capabilities of sorting, query handling and integrity checking and easy access to data.
The disadvantages are that Database Management System has few graphical capabilities; it also requires expertise (i.e. a Database Administrator (DBA) to maintain the database) and resources to administer it.