Oracle Database/Introduction

Oracle RDBMS is one of the most used. It has been created in 1979 and its request language is called the.

Installing Oracle
As with most software products, it must be installed; Windows, Linux and Unix versions are available for use, and there are different editions available.


 * Express Edition (XE)download is free but uses a slightly older version of the Oracle database engine, and has upper RAM and storage limits of 4 GB in mono-processor. It is not available for Unix and needs to register online.
 * Standard Edition One removes the basic limitations for storage, and will support multi-cpu systems.
 * Standard Edition (SE) provides additional features pertaining to cluster management (Oracle Real Application Clusters, alias ), and may be run on systems containing additional CPUs.
 * Enterprise Edition (EE) has no limitations, and may also include optional features that are suitable to large corporations.
 * Personal Edition (PE) is not provided for the 12th version. It was a kind of single user Enterprise Edition.

Once downloaded, the .zip file(s) must be extracted, if they are two their folders must be merged (they are named "database"). Then launch to install:
 * In Linux, runInstaller.sh.
 * In Windows, setup.exe.

Starting script
Oracle Database launches automatically at each boot, which is useful for a server but slows the system significantly for a PC which isn't supposed to use it in full time. To avoid this we can create a simple script to launch and stop Oracle manually:
 * In Linux : remove Oracle from the daemons (eg: /etc/init.d ).
 * In Windows : execute services.msc, and toggle the services OracleServiceXE and OracleXETNSListener in manual start. When you need to use Oracle, launch as an administrator, the following script Oracle.cmd:
 * For the XE version:
 * For the SE version:

If the message "Access denied" occurs, relaunch the script with a right click, as an administrator.

Identifying system requirements
The database server needs at least :
 * 1) 1 GB free space on a hard drive for XE, 3.5 for SE.
 * 2) 1 GB RAM.
 * 3) Windows, Linux, Oracle Solaris, or IBM AIX.

Since the version 12c, a 64 bits processor is mandatory.

The environment variables settings are automatic.

The system objects naming follows the Optimal Flexible Architecture (OFA).