Oracle Fundamental

Oracle is relational database management system software and also supports features of ORDBMS. Actually Oracle is a brand and company that provide following features like:

OS- Operating System

ERP- Enterprise Resource Planning

DWH- Data Ware Housing

Now, Let’s Discuss DB(Database) in details:

• DB (Database)- Oracle database is available in various version and various editions.

             versions of Oracle:-

             oracle 1,2,3,4,5,6,7,8,8i,9i,10g,11g and 12c.

i- stands for Internet

g- stands for grid

c- stands for cloud

Edition of Oracle:- there are many edition but famous are two.

• Enterprise Edition (EE)- It supports all the features.
• Express Edition- It doesn't supports all features like “table partitions”, “Flashback” and more. you can download this software from Internet and use it without taking any licence.

when you install oracle in your local machine there are following components get installed in your computer.

1. DB (Database)
2. Instance
3. Client

1. DB- it will create a default database for practice purpose. XE created in express edition where ORCL created in Enterprise Edition.

It will create two types of database that is physical database and logical database.

• Physical Database: It contains Data files. the extension of database file is .DBF and all oracle data stored in these files.  
• Logical database: Logical database is associated with physical database. you can also understand like, user interacting. it means when you execute any query like “select * from table_name”, then it will return on tabular format. so work of logical database to contain tables and tablespaces.

2. Instance: Instance is the way to access database. Actually database is also associated with instance. DB is created in HDD(Hard disk) where Instance is created on RAM of your machine. when you execute any query all the operation happened on Instance and when you save, then it goes on DB.

• Oracle server: Oracle server contains and manage two components that is Instance and DB. so wherever these database is created is called Oracle server.

3. Client: Client is just user of that services. A client can connect to the oracle server, submit request to the server, receive response from the server. In other words client is tools or software that helps to make request to the server like user agent.

There are various client are available:

SQL Plus

Toad

SQL Developer

PL/SQL Developer

JDeveloper

Note: This is the basics of Oracle, and next we will discuss about Language of Oracle.

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thank you

Sunny kumar(Rebel)