Introduction Oracle

Ø Data :
It is raw fact through which an object can‘t be identified.

Ex – employee no. name, salary of an employee are individually known as one one data

Ø Information

Organized collection of related data is known as information through which an object can be clearly identified.

It is raw fact through which an object can be identified.

Ex – employee no. name, salary of an employee are individually known as one one data

Ø Data file

Organized collection of related information is known as a data file.

Ex – sales dept, purchase dept, admin dept of a particular company individually maintains their data file.

NOTE

Through data is a raw fact through which an object can‘t be identified but it minimum requirement of data base.

Ø Why data base ?

Data is maintained to keep track on object day to day traction. The advantage of data base management is to know assets / liability, profile /loss of an organization.

Database has no scope that means it can be implemented on small scale corporate house.

Ø MEDIAS TO MAINTAIN DATABASE

To maintain database three diff Medias are available

a) Paper or cabinet file

b) Spread sheet

c) DBMS: ” It is basically software responsible to store, retrieve and modify the data of a database on user request.”

Till date computer has seen 4 types of databases.

1. Network

2. Hierarchical
3. Relation
4. Object relation

The primary jobs of above database are same i.e. to store data, but there are divided into 4 diff categories depending on their storage architectures. These databases are also known as data models or data architectures.

Depending on the support to the databases DBMS is also categorized into 4 diff types namely

1. NDBMS

2. HDBMS
3. RDBMS
4. ORDBMS

DBMS                           RDBMS                                  ORDBM

FoxPro                          oracle 6, 7                                  oracle 8

Dbase                           access                                        oracle 8i

FoxBASE                     SQL server                                   oracle 9i

Paradox db2,               Informix                                       oracle 10g

RDBMS is not software typically rather than it is a concept or theory developed by a scientist called DR JOHN E.F.CODD the prescribed 12 diff rules for relation architecture. Any database that support 6 or more then 6 rules will know as relational database and to manipulate them software has to be RDBMS type.

It any support less than 6 rules will known as general database and to manipulate it DBMS software is available.

Ø Def(RELATIONAL DATABASE)

 
“It is nothing but the organized collection of two dimensional tables or relations”.

EMP

EMP no     1              2             3            4

Name         a              b            c             d

Sal.         5000       6000        4550       7550

Above graphics shows the relational models of architecture. In relation model of architecture always data present in diff. diff. modules, each module is known as a table has a relation with another one.

The primary advantage of relational architecture is supports less data redundancy and more data security.