Mis Database Notes

7/29/2019 Mis Database Notes

1/10

MANAGEMENT

INFORMATION SYSTEM


2/10

DATABASE SYSTEM

A database system is a computer based record keeping system whose overall purpose

is to record and maintain information that is relevant to the organization for making

decisions. A database may also be described as a collection of data (or facts) that

are logically organized and can easily be searched or manipulated.

A database is in essence one or multiple computer files that encode data in a

highly structured format.The following systems are used in various applications

Ban king System and ATM

Stock Trading Systems.

Flight Reservation System

Computerized Library System

Super Market Product Inventory System.

2


3/10

COMPONENT OF DATABASE

SYSTEMDatabase system consist of four component

Data

Hardware

Software

Users

DataData act as bridge between the machine part i.e hardware, software and the

users which directly access it through some application programs. Data

may be of different types.

User data: This consist of tables of data called relation(s)s.

where Columns are called fields of attribute where rows are called records

of table.

3


4/10

Metadata: is a description of the database structure. it basically means

data about data. System Table stores the metadata which includes:

Number of Tables and Table Names, Number of fields and field Names and

Primary Key Fields.

Hardware: consists of secondary storage device such as magnetic disk (

hard disk zip disk floppy disk), optical(CD-ROM), MAGNETIC tapes etc.

on which data is stored together with the output/input devices (mouse,

keyboard, printers).

Software: consistof database management which acts as a bridge between

the users, application programs , and database and files system of a

particular storage media (hard disk, magnetic tapes etc) to insert, update,

delete and retrieve data.

Users: Users are those persons who need the information frome the

database to care out their primary responsibility ie personnel, staff,

clerrical, managers executives, etc.

4


5/10

Types of Data Bases

There are 5 types of databases

Hierarchical model

Network Model

Relational Model

Multidimensional Model

Object Model

5


6/10

Hierarchical structure

This isstructure is simple but none flexible because the relationship isconfined to a one-to-many relationship .IBMS IMS system and the RDM

Mobile are examples of a hierarchical database system with the multiple.

The hierarchical structure is used primarily today for storing geographic

information and file systems.

6


7/10

Network structureThis consist of more complex relationships unlike the hierarchical structure ,it can

relate to many records and access them by following one of several path. In

order words the structure allows from many-to-many relationships.

Relational structureIt is used by mainframe, midrange and microcomputer system. it uses two

dimensional rows and columns to store data. The tables of records can beconnected by common key values.

Multidimensional StructureThis dimensional is similar to the relational model, the dimensions of the cube-like

model have data relating to element in each cell. This structure gives aspreadsheet-like view of data.

Object oriented structure: this structure has the abilityto handle graphics, pictures, voice and text, types of data, This structure is

popular for multimedia web-based applications. It is designed to work withoriented ro rammin lan ua es such as JAV A.

7


8/10

DATABASE MANAGEMENT SYSTEMDatabase management system(DBMS) is the category of computer software

programs used for creating, organizing, retrieving, analyzing, and sorting

information in computer-based databases. It helps to specify the logicalorganization for a database access, enforcing data integrity, managing

concurrency, and restoring the database from backups.

Database and DBMS Structure

This units of database within a database are called records Each record isunique and is further broken down into a limited number of fields which

describes attributes of the record. For example, in an employee database, a

record exists for each employee, and the fields within each records may be

designated with each employee names, title, salary, date of hire, telephone

extension, supervisor name and so forth.

8


9/10

Functions of DBMSThere are various functions of a database which are listed as follows;

The ablity to retrieve and update data

This is a fundamental component of a DBMS essential to databasemanagement.without the ability to view or manipulate data,there would be

no point using a database system.

Support Concurrent Updates

Concurrence updates occur when multiple users make update to the database

simultaneously. Supporting concurrency updates is also crucial to databasemanagement as this component ensures that updates are made correctly and

the end result is accurate.

Security

Security is the prevention of unauthorized users accessing the database.DBMS

uses features such as encrypton, authentification, authourization and viewsto provide security to the database. Encrypton is when DBMS converts the

data in a database to an indecipherable format.

Data Integrity

9


10/10

Data integrity is an important function in database management, this is a set

of rules that DBMS provides to see that data integrity is enforced, thus

avoiding incorrect or inconsistent data, Types of DBMS provisions are data

type, legal values and format.

Database Administrator(DBA)The people responsible for the management of databases are called databaseadministrators. Each database administrator, dubbed DBA for the sake of

brevity, may be engaged in performing various database manipulation tasks

such as archiving, testing, running, security control, etc. Most of the major

vendors who provides database solutions also offer courses to certify the

DBA.

10

Documents

Mis Database Notes