Oracle 11g 12c

General Information About Oracle

Oracle is a brand it has Databases, Application Development Tools, ERP’s (Enterprise Resource Planning Tools), Data Warehouse and so on.

Below are examples for Database, Application Development Tools, ERP’s and Data Warehouse Tools

Database’s	Application Development Tools	ERP (Enterprise Resource Planning Tools)	Data warehouse Tools
Oracle 9i/10g/11g/12c	Java SE	Oracle EBS (Enterprise Business Solution)	OBIEE (Oracle Business Enterprise Edition)
Mysql	Java EE	Oracle Fusion	ODI (Oracle Data Integrator)
	ADF (Application Development Framework)

Oracel 11g/12c it is a Database software or Back End Tool. This is available in different editions and versions

Editions:-
Enterprise Edition (Licensed):- It is a licensed source one has to purchase this edition. It supports all the features of Oracle.
Express Edition (Open source):- It is a open source any one can download and install this. It doesn’t support some features like Flashback, Partitioning etc.,

Versions:-

 The versions of oracle are 1,2,3,4,5,6,7,8,8i,9i,10g,11g and now it is 12c

Here

 “ i ” refers to Internet

“ g ” refers to Grid

“ c ” refers to Cloud

From oracle version 8 onwards it is capable of storing Audio, video, images and oracle became best database for internet applications, so in the next version suffix “ i “ is added.

Before <9i version it was single server. If you see the diagrammatic representation of below 9i version, it was like this.

Greater than or equal to 9i (>=9i) a grid concept was introduced in “ 9i ”, from oracle “ 9i ” onwards database can be accessed through multiple servers (Grid), Even if one server is fail database can be accessed through another server.

The grid version mainly used by the medium and large scale companies for small company’s single server is enough to run business. Grid version means multiple servers this is expensive and small company’s will not bear.

    If any of the company asks for Grid version the developers first asks how many nodes the client is needed, here nodes means servers.

   Till the grid version the method of installation was one method that is ON PREMISES. ON PREMISES is the method of installing software where the developers will go to the client company and installs the software in their system on premises. 

Cloud:-

From Oracle 12 onwards Oracle supports cloud, Oracle database can be added to cloud, users connect to the cloud and access databases.

In cloud there are 2 methods of installing Oracle software in client company. One is ON PREMISES and the other is ON CLOUD.

   As we seen what is ON PREMISES in above grid version. ON CLOUD means Oracle software is purchased by a third party. That third party offers company to perform its operations with that software. 

   This will reduces the cost for the company, instead of purchasing it pay's some amount to the third party which offers the software.

   Oracle supports SaaS (Software as Service).

After Oracle Installation

After installing oracle the following components are installed in system.

○ Database

○ Instance

○ Tool (Client)

Database:-  A sample database is created.

If it is Express Edition XE will be created.

If it is Enterprise Edition ORCL will be created.

◘ Database is created in system Hard disk(Permanent Memory). It is created with following files

            • DBF (Data base file)

            • Redolog files

            • Control files

DBF it means Data base file, these are mainly used for backup. The data stored in the DBF.

Database cannot be accessed directly.

Instance:- Database is accessed through instance, Instance is created in RAM (Random Access Memory) which is a temporary memory.

The system in which both instance and database are resided that system is called as Oracle server.

Client:- It is tool which helps to connect Oracle server.

○ Using client tool, Users

• Can connect to Oracle Server

• Can submit requests

• Receive response from server

Different Client Tools are:-

○ SQL Plus

○ SQL Developet

○ TOAD

○ RUN SQL Command Line

SCHEMA:- A user in oracle database is called schema. The architecture of database, schemas and objects will be like

DATABASE

            USERS (Schema)

                        OBJECTS (Schema Objects)

List of schema objects in oracle are:

○ Tables

○ Views

○ Synonyms

○ Sequences

○ Indexes

○ Clusters

○ Materialized Views

○ Procedures

○ Functions

○ Packages

○ Triggers