In this chapter a brief introduction to Oracle 10g is given. The topics covered are as follows:
Data is a collection of information
Database is regarded as a repository of data stored in an organised manner.
Stored data must be usable. Storing/retrieving data, deletion of data, modification of existing data are the basic database operations. A software tool or programme that handles these operations is called Database Management System.
There are several database management systems - dBase III Plus, mFoxplus, MS-Access etc, each of which has its own size and performance limitations.
Further developed form of DBMS is RDBMS - addition of Relational feature. Here, the data stored in different forms, files or locations will have some sort of Relation through which, operations on data becomes more flexible and performing better.
A small example demonstrates the Relational feature.
Consider a database with the following tables:
Points to be noted:Each employee's department details need not be repeated in the 'employee' table.
Wherever an employee's department details are not needed, dept table need not be accessed.
'dept_no' column works as a relation between these two tables.
There are several database models out of which three are prominent
Oracle database comes under Relational model
Actually, Oracle database is ORDBMS - an advanced model of RDBMS with additional Object feature.
SQL is the most common method of interacting with Oracle. Using SQL, you can easily interact with relational databases without having to write complex computer programs or needing to know where or how the data is physically stored on disk. Data is stored, retrieved and deleted using SQL statements. SQL statements can be issued using command line SQL tools - SQL*Plus or iSQL*Plus.
PL/SQL is an Oracle specific extension of SQL enabling all programming aspects such as functions, procedures, looping, recursion etc.
A command line interface for using SQL for undertaking database activities. This feature is also available in GUI mode by using the command sqlplusw at command prompt.
A Graphical User Interface for configuring and creating databases.
A GUI interface for Database creation, administration, networking etc. All activities that are carried out under different user interfaces are also can be done using Enterprise Manager.
In addition to above interacting tools, Java and other OCIs are available to support advanced programming languages like C, C++ etc.
DBA's job includes installation of Oracle 10g software.
Before installing software, review the the System Requirements:
To do this, check whether the server meets the following requirements:
Free Disck Space
: 512 MB|
: 1 GB
: 400 MB
: 1.5 GB for installation and
1 GB for creation of Database
Next step is to plan your installation. To simplify the installation, a directory organisation / file naming method termed as Optimal Flexible Architecture (OFA) is introduced by Oracle. model is to be adopted.
OFA model conventionally defines naming conventions for file systems, mount points, directory paths, standardised locations for files.
Using this model simplifies later day identification of oracle software and files location
Oracle Universal Installer (OUI) is used to install and configure the Oracle 10g software. OUI is a Java based application which behaves in the same manner irrespective of the Operating System.
To run OUI, run the runInstaller.sh command on Unix or run setup.exe file provided in the Oracle 10g software CD on Windows. Installation is self explanatory. Respond to the resulting screens and provide with the required options for installation.
After the installation of Oracle 10g software is finished, your next task will be to create a Database.
In the next lesson, we will learn how to create a Database using Database Configuration Assistant (DBCA).