Introduction to DBMS (Data Base Management System)

A database management system (DBMS) that incorporates the relational-data model, normally including a Structured Query Language (SQL) application programming interface. It is a DBMS in which the database is organized and accessed according to the relationships between data items.

Introduction To DBMS

The term database is made up of two seprarate words ,data and base . Database is a base for data an assembled group of data . A database allowes easy and efficient storage, retrievel and modification of data, regardless of the amount of data manipulated, essentially, database is a computerised record keeping system .

A database  is a logically coherent, organised collection of similar data . similar data refers to the collection of data, which is stored based on the same context. for example, an Employee database contains 'similar' data. For aal employees and every employee's entry contains a similar type of information. the organised information serves as base from which desired information can be retrieved,conclusions can be drawn and decision can be made by further reorganising or processing this data. In essence, a database not only stores information, but the information is integreated so that when the database is interrogated, users can get something usehul from it. "A Database Management System (DBMS) is a collection of interrelated data and a set of programs to access those data." The collection of data, usually reffered ta as the database, contain information that is both convenient and efficient.

• Database is the combination of two words:
• Database+Management System = DBMS

A database is a collection of related information stored, so that it is available to many users for different purposes.

             Application  ↔  DBMS ↔ O.S  ↔ Database 

On the other hand , management system is a collection of proprams that enables users to create and maintain the database.

DBMS can also be define "as an interface between the application program and the opreating system to access to manipulate the database"

A DBMS is a software System that allows access to data contained in the database. It's objective is to provide a convenient and effective method of defining, storing and retrieving the information contained in the database. The DBMS interfaces with application programs so that the data contained in the database can be used by multiple application and users.

Need For DBMS

Historically, information systems employed stand-alone systems for separate application each with their own set of files. this implied the data such as addresses, may be duplicated in many separate systems, such as an employee's address may be held once in the payroll systems and again in the personal systems.This Causes waste of space and inconsistency. there may be a possibility for the address to be updated in one system but not in the other, hence, making the data in consistent.

The problems described above led to development of the database approach, an organization attempts to build an integrated corpporated database to support all the data requirements of the organisation. DBMS are very good at organising and maintaining large collections of persistent data. A DBMS is like a suitcase where all the stuff (data) is out so that it is in one place and easy to reach. This protect data from unauthorised acess and accidental corruption or loss due to hardware and software failures. DBMS allows concurrent acess, meaning that a single data set can be accessed by more than one user at a time.