What is Oracle? A Visual Definition

By: Wade Harvey



Historical Origins

In 1977, Larry Ellison and two of his friends, Bob Miner and Ed Oates, began a company named Software Development Laboratories, and they developed the original Oracle (). They named the product after a code name project that they had worked on at a company called Ampex. In 1979, Software Development Laboratories was renamed to Relational Software Inc (RSI), and the RSI company was later renamed to Oracle Corporation in 1984.

Major Components of Oracle DBMS

An Oracle consists of a database and an instance.

A database includes all of the physical data files, control files, and redo log files that hold Oracles metadata and your data. Data files hold your actual data and indexes. Redo logs contain records of all changes that have been made. Control files hold important Oracle metadata. Control files contain all the information that instance needs to access a database.

An instance is a combination of the pool of physical memory (RAM) allocated to Oracle and the background processes that Oracle creates to use this memory pool. The RAM is called the SGA (System Global Area). RAM is used to cache data because RAM is about one thousand times faster that disk I/O. Here are the major processes that run in the background:

1. DBWR process that copies data in the RAM to the disk files
2. LGWR records changes applied to data in the redo log for recovery purposes in the event of a problem.
3. PMON Performance Monitor performs cleanup of failed user and server processes.
4. SMON System Monitor performs instance recovery in case server shuts down improperly.
5. CKPT Takes account whenever DBWR writes information from memory to disk.

Versions

The “i” in the version name emphasizes the internet functionality and the “g” emphasizes that the version is “grid-computing” ready.

Date Version Features
1979 Oracle V2 SQL queries and joins
1983 Oracle V3 Commit, Rollback, Unix, Rewritten in C
1984 Oracle V4 Read Consistency
1985 Oracle V5 Distributed Queries
1989 Oracle V6 ERP Financials, PL/SQL , row-level locking, hot backups
1992 Oracle V7 referential integrity, stored procedures, triggers
1997 Oracle V8 object-oriented
and multimedia
1999 Oracle 8i incorporated a native Java Virtual Machine (JVM)
2001 Oracle 9i XML, Real Application Clusters (RAC), cluster database
2003 Oracle 10g grids
2007 Oracle 11g  

Editions

Edition Features Price
Standard Edition Licensed
by users or processors; 1-4 cpus
$15,000 per CPU
Enterprise Edition Increased performance and security $40,000 per CPU
Standard Edition One Scaled-down Standard Edition $5,000 per CPU or $149 per user
Express Edition Max
of 4GB user data; single CPU, requires 150MB
Free
Oracle Personal Edition Same functionality as Enterprise Edition, but licensed to single-user developers  
Oracle Database Lite Intended to run on mobile devices  

Client-Side Utilities

SQL*Plus – for creating and testing command-line SQL Queries and executing PL/SQL procedural programs.
Oracle Developer Suite – for developing database applications including the following developer tools:

  1. Forms Builder – for creating custom user applications
  2. Reports Builder – for creating reports for displaying, printing, and distributing summary data.
  3. Enterprise Manager – for performing database administration tasks such as creating new user accounts and configuring how the DBMS stores and manages data.

Further Study

There is an excellent set of study guide workbooks from Oracle University that you can get by clicking on this link: Oracle University Workbooks