Preface

This reference contains a complete description of the Structured Query Language (SQL) used to manage information in an Oracle Database. Oracle SQL is a superset of the American National Standards Institute (ANSI) and the International Standards Organization (ISO) SQL:1999 standard.

This preface contains these topics:

• Audience

• Organization

• Related Documentation

• Conventions

• Documentation Accessibility

Audience

The Oracle Database SQL Reference is intended for all users of Oracle SQL.

Organization

This reference is divided into the following parts:

Chapter 1, " Introduction to Oracle SQL"

This chapter discusses the history of SQL and describes the advantages of using it to access relational databases.
Chapter 2, " Basic Elements of Oracle SQL"

This chapter describes the basic building blocks of an Oracle Database and of Oracle SQL.
Chapter 3, " Pseudocolumns"

This chapter describes Oracle SQL pseudocolumns.
Chapter 4, " Operators"

This chapter describes Oracle SQL operators.
Chapter 5, " Expressions"

This chapter describes Oracle SQL expressions.
Chapter 6, " Conditions"

This chapter describes Oracle SQL conditions.
Chapter 7, " Functions"

This chapter describes how to use built-in Oracle SQL functions.
Chapter 8, " Common SQL DDL Clauses "

This chapter describes a number of DDL clauses that are frequently used in many top-level SQL statements.
Chapter 9, " SQL Queries and Subqueries"

This chapter describes the different types of SQL queries.
Chapter 10 Through Chapter 19

These chapters list and describe all Oracle SQL statements in alphabetical order.
Appendix A, " How to Read Syntax Diagrams"

This appendix describes how to read the syntax diagrams in this reference.
Appendix B, " Oracle and Standard SQL"

This appendix describes Oracle Database compliance with ANSI and ISO standards.
Appendix C, " Oracle Regular Expression Support"

This appendix describes Oracle Database compliance with the POSIX regular expression standard and to the Unicode Regular Expression Guidelines of the Unicode Consortium.
Appendix D, " Oracle Database Reserved Words"

This appendix lists words that are reserved for internal use by Oracle Database.
Appendix E, " Examples"

This appendix provides extended examples that use multiple SQL statements and are therefore not appropriate for any single section of the reference.
Structural Changes in the SQL Reference in Oracle Database 10g Release 1

The section on pseudocolumns, formerly part of Chapter 2, is now a separate chapter: Chapter 3, " Pseudocolumns".

The section CREATE TEMPORARY TABLESPACE has been combined with the section CREATE TABLESPACE , because temporary tablespaces are a form of tablespace.

Related Documentation

For more information, see these Oracle resources:

• PL/SQL User's Guide and Reference for information on PL/SQL, the procedural language extension to Oracle SQL

• Pro*C/C++ Programmer's Guide, Oracle SQL*Module for Ada Programmer's Guide, and the Pro*COBOL Programmer's Guide for detailed descriptions of Oracle embedded SQL

Many of the examples in this book use the sample schemas of the seed database, which is installed by default when you install Oracle Database. 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 in Text

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.

Convention	Meaning	Example
Bold	Bold typeface indicates terms that are defined in the text or terms that appear in a glossary, or both.	When you specify this clause, you create an index-organized table.
Italics	Italic typeface indicates book titles or emphasis.	Oracle Database Concepts Ensure that the recovery catalog and target database do not reside on the same disk.
UPPERCASE monospace (fixed-width) font	Uppercase monospace typeface indicates elements supplied by the system. Such elements include parameters, privileges, datatypes, RMAN keywords, SQL keywords, SQL*Plus or utility commands, packages and methods, as well as system-supplied column names, database objects and structures, usernames, and roles.	You can specify this clause only for a NUMBER column. You can back up the database by using the BACKUP command. Query the TABLE_NAME column in the USER_TABLES data dictionary view. Use the DBMS_STATS.GENERATE_STATS procedure.
lowercase monospace (fixed-width) font	Lowercase monospace typeface indicates executables, filenames, directory names, and sample user-supplied elements. Such elements include computer and database names, net service names, and connect identifiers, as well as user-supplied database objects and structures, column names, packages and classes, usernames and roles, program units, and parameter values. Note: Some programmatic elements use a mixture of UPPERCASE and lowercase. Enter these elements as shown.	Enter sqlplus to open SQL*Plus. The password is specified in the orapwd file. Back up the datafiles and control files in the /disk1/oracle/dbs directory. The department_id, department_name, and location_id columns are in the hr.departments table. Set the QUERY_REWRITE_ENABLED initialization parameter to true. Connect as oe user. The JRepUtil class implements these methods.
lowercase italic monospace (fixed-width) font	Lowercase italic monospace font represents placeholders or variables.	You can specify the parallel_clause. Run Uold_release.SQL where old_release refers to the release you installed prior to upgrading.

Conventions in Code Examples

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.

Convention	Meaning	Example
[ ]	Brackets enclose one or more optional items. Do not enter the brackets.	DECIMAL (digits [ , precision ])
{ }	Braces enclose two or more items, one of which is required. Do not enter the braces.	{ENABLE | DISABLE}
|	A vertical bar represents a choice of two or more options within brackets or braces. Enter one of the options. Do not enter the vertical bar.	{ENABLE | DISABLE} [COMPRESS | NOCOMPRESS]
...	Horizontal ellipsis points indicate either: That we have omitted parts of the code that are not directly related to the example That you can repeat a portion of the code	CREATE TABLE ... AS subquery; SELECT col1, col2, ... , coln FROM employees;
. . .	Vertical ellipsis points indicate that we have omitted several lines of code not directly related to the example.	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.
Other notation	You must enter symbols other than brackets, braces, vertical bars, and ellipsis points as shown.	acctbal NUMBER(11,2); acct CONSTANT NUMBER(4) := 3;
Italics	Italicized text indicates placeholders or variables for which you must supply particular values.	CONNECT SYSTEM/system_password DB_NAME = database_name
UPPERCASE	Uppercase typeface indicates elements supplied by the system. We show these terms in uppercase in order to distinguish them from terms you define. Unless terms appear in brackets, enter them in the order and with the spelling shown. However, because these terms are not case sensitive, you can enter them in lowercase.	SELECT last_name, employee_id FROM employees; SELECT * FROM USER_TABLES; DROP TABLE hr.employees;
lowercase	Lowercase typeface indicates programmatic elements that you supply. For example, lowercase indicates names of tables, columns, or files. Note: Some programmatic elements use a mixture of UPPERCASE and lowercase. Enter these elements as shown.	SELECT last_name, employee_id FROM employees; sqlplus hr/hr CREATE USER mjones IDENTIFIED BY ty3MU9;

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/

Accessibility of Code Examples in Documentation

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.

Accessibility of Links to External Web Sites in Documentation

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.