Database Tutorial

Explaining Data & Databases

Data is a collection of data items, such as numbers, words, measurements etc.
Database is an organized collection of related data, such as schema, tables, queries, views etc. that are stored at one place.

Introduction to DBMS

  • Database Management System (DBMS) is a program that helps to store, modify and extract the information from a database.
  • DBMS is also known as Computerized Record-Keeping System.
  • It helps in the process of defining, constructing, manipulating the database.
  • It has become an integral part of the information system of many organizations because DBMS handles huge amount of data.
  • DBMS is useful for providing a centralized view of data that can be accessed by multiple users from multiple locations.

Features of DBMS

  • DBMS supports manipulation and processing of the data.
  • It provides security and access control of data.
  • It has ability to view the database from different viewpoints according to the user requirements.
  • It stores and manages the information in a digital repository established on a server or mainframe system.
Other features of DBMS,
  • Data Security
  • Data Independence
  • Back up and Restore
  • Transaction and Concurrency Control
  • Data Security
  • Data Integrity

File System v/s DBMS

ParametersDBMSFile System
MeaningDBMS is a collection of data and set of programs to access those data.File system is an abstraction to store, retrieve and update a set of files.
Data RedundancyRepetition of data can be reduced.Repetition of data cannot be reduced.
Data InconsistencyInconsistency of data can be avoided.Inconsistency of data cannot be avoided.
Data InconsistencyInconsistency of data can be avoided.Inconsistency of data cannot be avoided.
Sharing of DataData can be shared easily.Data cannot be shared easily. There is difficulty in accessing the data.
Data IntegrityThe data can be accessed from the database through physically as well as logically.Data independence cannot be provided to access the data.
Response to RequestIt gives fast response to information request because the data are integrated into a single database.It gives slow response to information request.
SecurityIt restricts unauthorized access.Lack of security.
Concurrency ControlData can be accessed by multiple users at same point of time.Problem in concurrency control.
Data RecoveryIt provides back up of data and restores the database to its original state after database failure.It does not provide back up and data recovery. The data may loss if the operation is failed.