Explain the Importance of Database Systems? (or) Why Database Systems , its Evolution and Development in the organizations?

Database systems consists of logically related data stored in a single logical data repository.  Logical refers in the fact that, although the data repository appears to be a single Unit to the end users, its actually  and physically  distributed among multiple data storage facilities in different locations.

The DB represents a major change in the way End users data are stored, accessed and managed through data repository which Is a logical unit. It provides numerous advantages over File system management and thus making it possible to eliminate most of the file system’s draw-backs,

  · Data Inconsistency

       ·  Data Anomalies

       ·   Data Dependency

       ·   Structural depending problems, etc.

DBMS software not only stores the data structures, but also the relationships between those structures and access paths, all in a central location. Thus,  DBMS software takes care of defining, storing, managing and manipulating, with overall required access paths to those components.

Database System Environment:   It refers to an organization of components, that define and regulate the collection, storage, management and use of data within the DB Environment. The DB system environment is composed of Five major parts, as

    1.  Hardware (H/w)  

      

    2.  Software (S/w)     

  

    3. People   

     

    4. Procedures and

    5. Data

Hardware refers to all system’s physical devices, ie. Computer components, storage devices, Network devices and printers and other devices attached to the system.

Although software is DBMS itself, there are 3 types of Softwares needed.

      a)  Operating System (O/s)  

                   

      b)  DBMS S/w   

           

      c)  Application Programs and other   Utilities.                                                                                                 

O/s manages all H/w components and makes it possible all s/w to run on Computer. 

Ex:  MS-Windows, Linux, Mac OS, Unix Xenix, MVS etc

DBMS s/w manages the database within DBMS S/w includes MS-SQL server, Oracle, MYSQL, IBM’s DB2

Application programs and utilities, used to access and manipulate data. Application programs are most commonly used to access data found within the DB to generate reports, tabulations, other information to facilitate decision making.

The utilities are the S/w tools used to help and manage database systems computer components. The major DBMS vendors provide GUI to help to create DB Structures, Control DB access and Monitor DB Operations.

People:  People includes all users of the database system. There are 5 types of users, viz.

    1.       Systems Administrators

    2.      Database Administrators

    3.      Database Designers

    4.      Systems Analysts

  

    5.      Programmers and End-users.

Procedures:  Procedures are the instructions/ rules that govern the design and use of DB System. Procedures are important because they enforce the standards by which business is conducted. They are also used to ensure that there is an organized way to monitor and Audit both data that enter in the DB and the information that is generated with the use of that data.

Data:  Data is the collection of facts stored in the DB. Data are the raw material from which information is generated. What data are to be entered into the DB and how that data are to be organized is a vital part of the Database.

DBMS Functions:

A DBMS performs some important functions that guarantee the Integrity and consistency of the data in the DB. Most of the functions are transparent to End-users, can be achieved through the use of DBMS. Thus, the functions are,

§  Data Dictionary management

§  Data storage

§ Data Transformation and Presentation

§  Security Management

§  Multi-User Access control

§ Back Up and Recovery management

§  Data Integrity Management

§  Database Access Language

§  Application Programming Interface and

§  Database Communication Interface.