Preface

This manual describes all features of the Oracle database server, an object-relational database management system. It describes how the Oracle database server functions, and it lays a conceptual foundation for much of the practical information contained in other manuals. Information in this manual applies to the Oracle database server running on all operating systems.

This preface contains these topics:

• Audience

• Organization

• Related Documentation

• Conventions

• Documentation Accessibility

Audience

Oracle Database Concepts is intended for database administrators, system administrators, and database application developers.

To use this document, you need to know the following:

• Relational database concepts in general

• Concepts and terminology in Chapter 1, " Introduction to the Oracle Database"

• The operating system environment under which you are running Oracle

Organization

This document contains:

This chapter provides an overview of the concepts and features you need for understanding the Oracle database server. You should read this overview before using the detailed information in the remainder of this manual.

This chapter discusses how data is stored and how storage space is allocated for and consumed by various objects within an Oracle database.

This chapter discusses how physical storage space in an Oracle database is divided into logical divisions called tablespaces. It also discusses the physical operating system files associated with tablespaces (datafiles) and files used in recovery (control files).

This chapter defines the concept of transactions and explains the SQL statements used to control them. Transactions are logical units of work that are run together as a unit.

This chapter describes the database objects that can be created in the domain of a specific user (a schema), including tables, views, numeric sequences, and synonyms. Optional structures that make data retrieval more efficient, including indexes, materialized views, dimensions, and clusters, are also described.

This chapter explains how Oracle manages the dependencies for objects such as procedures, packages, triggers, and views.

This chapter describes the data dictionary, which is a set of reference tables and views that contain read-only information about an Oracle database.

This chapter describes the memory structures used by an Oracle database system.

This chapter describes the process architecture of an Oracle instance and the different process configurations available for Oracle.

This chapter discusses distributed processing environments in which the Oracle database server can operate.

This chapter describes Oracle database utilities for data transfer, data maintenance, and database administration. These include Data Pump Export/Import, SQL*Loader, and LogMiner.

This chapter describes an Oracle instance and explains how the database administrator can control the accessibility of an Oracle database system.

This chapter explains how Oracle provides concurrent access to and maintains the accuracy of shared information in a multiuser environment. It describes the automatic mechanisms that Oracle uses to guarantee that the concurrent operations of multiple users do not interfere with each other.

This chapter describes features for managing database use, such as Oracle Enterprise Manager, Automatic Storage Management, the Database Resource Manager, and the Scheduler.

This chapter introduces database concepts that are fundamental to backing up a database. It also introduces the structures that are used during database recovery.

This chapter provides an overview of Oracle's high available features, including data protection, online reorganization and redfinition of tables and indexes, dynamic resizing of memory structures, and database repair.

This chapter describes Oracle's business intelligence features, including data warehousing, parallel execution, data mining, and OLAP functions.

This chapter describes how partitioning can be used to split large tables and indexes into more manageable pieces.

This chapter provides an overview of Oracle's content management features, including XML, Oracle Text, Oracle Ultra Search, and Oracle Spatial.

This chapter describes how to control user access to data and database resources. It also discusses security at the system and schema object levels, and it explains how Oracle auditing tracks database activity.

This chapter discusses data integrity and the declarative integrity constraints that you can use to enforce data integrity.

This chapter discusses triggers, which are procedures written in PL/SQL, Java, or C that run implicitly whenever a table or view is modified or when some user actions or database system actions occur.

This chapter explains Oracle's various solutions for operating in a distributed environment, including Oracle Streams and Distributed SQL.

This chapter briefly describes SQL (Structured Query Language), the language used to communicate with Oracle, as well as PL/SQL, the Oracle procedural language extension to SQL. It also discusses the procedures, functions, and packages, which are PL/SQL program units stored in the database.

This chapter describes Oracle APIs for accessing various information.

This chapter describes the types of relational data that can be stored in an Oracle database table, such as fixed- and variable-length character strings, numbers, dates, and binary large objects (BLOBs).

This chapter gives an overview of the object extensions that Oracle provides.

The glossary defines terms used in this manual.

Related Documentation

For more information, see these Oracle resources:

• Oracle Database Upgrade Guide for information about upgrading a previous release of Oracle

• Oracle Database Administrator's Guide for information about how to administer the Oracle database server

• Oracle Database Application Developer's Guide - Fundamentals for information about developing Oracle database applications

• Oracle Database Performance Tuning Guide for information about optimizing performance of an Oracle database

• Oracle Data Warehousing Guide for information about data warehousing and business intelligence

Many books in the documentation set use the sample schemas of the seed database, which is installed by default when you install Oracle. Refer to Oracle Database Sample Schemas for information on how these schemas were created and how you can use them yourself.

Printed documentation is available for sale in the Oracle Store at

http://oraclestore.oracle.com/

To download free release notes, installation documentation, white papers, or other collateral, please visit the Oracle Technology Network (OTN). You must register online before using OTN; registration is free and can be done at

http://otn.oracle.com/membership/

If you already have a username and password for OTN, then you can go directly to the documentation section of the OTN Web site at

http://otn.oracle.com/documentation/

Conventions

This section describes the conventions used in the text and code examples of this documentation set. It describes:

• Conventions in Text

• Conventions in Code Examples

• Conventions for Windows Operating Systems

We use various conventions in text to help you more quickly identify special terms. The following table describes those conventions and provides examples of their use.

Code examples illustrate SQL, PL/SQL, SQL*Plus, or other command-line statements. They are displayed in a monospace (fixed-width) font and separated from normal text as shown in this example:

SELECT username FROM dba_users WHERE username = 'MIGRATE';

The following table describes typographic conventions used in code examples and provides examples of their use.

[ ]

DECIMAL (digits [ , precision ])

{ }

{ENABLE | DISABLE}

|

{ENABLE | DISABLE}
[COMPRESS | NOCOMPRESS]

...

CREATE TABLE ... AS subquery;

SELECT col1, col2, ... , coln FROM employees;

.
 .
 .

SQL> SELECT NAME FROM V$DATAFILE;
NAME
------------------------------------
/fsl/dbs/tbs_01.dbf
/fs1/dbs/tbs_02.dbf
.
.
.
/fsl/dbs/tbs_09.dbf
9 rows selected.

acctbal NUMBER(11,2);
acct    CONSTANT NUMBER(4) := 3;

Italics

CONNECT SYSTEM/system_password
DB_NAME = database_name

UPPERCASE

SELECT last_name, employee_id FROM employees;
SELECT * FROM USER_TABLES;
DROP TABLE hr.employees;

lowercase

SELECT last_name, employee_id FROM employees;
sqlplus hr/hr
CREATE USER mjones IDENTIFIED BY ty3MU9;

The following table describes conventions for Windows operating systems and provides examples of their use.

c:\winnt"\"system32 is the same as C:\WINNT\SYSTEM32

C:\oracle\oradata>

C:\>exp scott/tiger TABLES=emp QUERY=\"WHERE job='SALESMAN' and sal<1600\"
C:\>imp SYSTEM/password FROMUSER=scott TABLES=(emp, dept)

HOME_NAME

C:\> net start OracleHOME_NAMETNSListener

Documentation Accessibility

Our goal is to make Oracle products, services, and supporting documentation accessible, with good usability, to the disabled community. To that end, our documentation includes features that make information available to users of assistive technology. This documentation is available in HTML format, and contains markup to facilitate access by the disabled community. Standards will continue to evolve over time, and Oracle is actively engaged with other market-leading technology vendors to address technical obstacles so that our documentation can be accessible to all of our customers. For additional information, visit the Oracle Accessibility Program Web site at

http://www.oracle.com/accessibility/

JAWS, a Windows screen reader, may not always correctly read the code examples in this document. The conventions for writing code require that closing braces should appear on an otherwise empty line; however, JAWS may not always read a line of text that consists solely of a bracket or brace.

This documentation may contain links to Web sites of other companies or organizations that Oracle does not own or control. Oracle neither evaluates nor makes any representations regarding the accessibility of these Web sites.