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Oracle Introduction

Before jumping to the topic of  oracle , there are somethings which are to be known. So lets take a while to know that first.


·          Data –raw facts.

·         Oracle –oracle is a corporation.

·         Products-oracle 9 i,oracle 10g.

·         Oracle is database software.


·         This works on client server architecture.

·         server-server is a computer[a highly configured computer]which shares common resources to their clients.

·         Client sends a request to the server the server approves the request and gives the response to the client.

·         Software-computer software also called as a program or simply software is any set of instructions that directs the computer to perform specific tasks or operation.

·         The computer software can be divided into 2 types: system software and application software.
·         System software:a set of things working together as parts of the mechanism or an interconnecting network i.e  a complex whole.
                                                                     (or)
·         a set of interacting or independent component parts forming a complex /intricate whole.

·         Application software: a set of instructions working together to perform a particular task, or helps in running a particular function is called application software.
·         Application software is dividedinto three types.namely, office application software,customized application software ,database management software(DBMS)

·         Office software: MS office is the best example for that.

·         Customizable software: TALLY ,DTP,FOCUS (all these are accounting software)these are a few example of customizable software.
·         Difference between a client and a customer:
·         Client: a person or organization using the services of a lawyer or other professional  or company.

·         Customer:a person who buys goods from a shop or services from a Shop or business management.
·         Data-plural

·         Datum-singular-whatever we can enter into the computer is called as data .

·         Data can also be called as raw facts.

·         Data never gives any meaning.

·         Information : processed data is called as information.
·         Meta data: as seen in the above diagram  all the information can be known by typing the employee id  no. such column can e called as meta data coloum(as all information may be gathered by typing the employee id only).



·         The different meanings of oracle are ;
·         A person who knows about the future.
·         Holy place for greek people .
·         Aakaskwani

3 types of user communicate with the database.
 End user (through online forms) , database developer, database administrator.

SQL-(structured query language) :-sql is a language which is used to communicate with the database.
This language was not developed by oracle.


SQL is a common language interface, it is common language interface because it is applicable on all kinds of database.
This language was developed by ef codd in the year 1968 .
This language was approved by ANSI(American national standard institute ) in the year 1970.
In the year 1972 this language came into the market.

Now talking about languages , there are two types of languages : 1. Procedural and 2. non procedural .
In common terms we say that in procedural languages we say “how to do” certain things. But ,in  non procedural language we say “what to do”.
·         Lets take a brief example of that: the task is to buy a pen from the shop .
·         In procedural language” take your valet , go to shop , select a pen, test that pen, go to the shop keeper ,buy that pen.
·         In nonprocedural language “go to shop and buy the pen.
Example of procedural language is “c”.
Example of non procedural language is “SQL”.
In procedural language we write programs , where as in non procedural language we don’t write programs.
Now talking about SQL , it is a non procedural language which is used to communicate with all types of database such as oracle,HANA,DB2,INFORMIX,SQL SERVER.

Features of SQL;
1.       SQL is not a case sensitive language. We can write SQL commands in capital and small and combination of capital and small letters also.
2.       Every command in SQL ends with semicolon.
3.       SQL can also be pronounced as sequel server.
4.       SQL can be called as natural language interface because every command in sql is almost similar to normal language.
5.       SQL can be called as common language interface because this is the only language to communicate with all types of database such as ORACLE,DB2,SQL server etc.


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