Preface

This reference manual describes the Oracle packages that are shipped with the Oracle8i, Release 8.1.5 program. Information in this manual applies to versions of the Oracle Server that run on all platforms, and it does not include system-specific information.

This Preface includes the following sections:

• Introduction to Packages

• Audience

• Related Documents

• Conventions

• Your Comments Are Welcome

Introduction to Packages

A package is a schema object that groups logically related PL/SQL types, items, and subprograms. Packages usually have two parts: a specification and a body, although sometimes the body is unnecessary. The specification is the interface to your applications; it declares the types, variables, constants, exceptions, cursors, and subprograms available for use. The body fully defines cursors and subprograms, and so implements the specification.

Unlike subprograms, packages cannot be called, parameterized, or nested. Still, the format of a package is similar to that of a subprogram:

CREATE PACKAGE name AS  -- specification (visible part)
   -- public type and item declarations
   -- subprogram specifications
END [name];

CREATE PACKAGE BODY name AS  -- body (hidden part)
   -- private type and item declarations
   -- subprogram bodies
[BEGIN
   -- initialization statements]
END [name];

The specification holds public declarations, which are visible to your application. The body holds implementation details and private declarations, which are hidden from your application.

You can debug, enhance, or replace a package body without changing the interface (package specification) to the package body.

To create packages and store them permanently in an Oracle database, use the CREATE PACKAGE and CREATE PACKAGE BODY statements, which you can execute interactively from SQL*Plus or Enterprise Manager.

Only the declarations in the package specification are visible and accessible to applications. Implementation details in the package body are hidden and inaccessible. So, you can change the body (implementation) without having to recompile calling programs.

The advantages of using packages include modularity, easier application design, information hiding, added functionality, and better performance.

Audience

This manual is intended for anyone who is using or is interested in Oracle packages. It will also be valuable to systems analysts, project managers, and others interested in the development and tuning of database applications.

This manual assumes that you have a working knowledge of application programming and that you are familiar with the use of Structured Query Language (SQL) to access information in relational database systems.

Certain sections of this manual also assume a knowledge of the basic concepts of object oriented programming.

Related Documents

For more information, see the following manuals in the Oracle8i documentation set:

• Oracle8i Application Developer's Guide - Fundamentals

• PL/SQL User's Guide and Reference

Conventions

The following conventions are used in this manual:

Convention	Meaning
. . .	Horizontal ellipsis points in statements or commands mean that parts of the statement or command not directly related to the example have been omitted
UPPERCASE TEXT	Uppercase text is used to call attention to package names, command keywords, database object names, filenames, and so on.
Italicized Text	Italicized words within text are book titles or emphasized words.
Code Examples	Commands or statements of SQL, Oracle Enterprise Manager line mode (Server Manager), and SQL*Plus appear in a monospaced font. For example: INSERT INTO emp (empno, ename) VALUES (1000, 'SMITH'); ALTER TABLESPACE users ADD DATAFILE 'users2.ora' SIZE 50K;
< >	Angle brackets enclose user-supplied names.
[ ]	Brackets enclose optional clauses from which you can choose one or none.
$	The dollar sign represents the DIGITAL CommandLanguage prompt in OpenVMS and the Bourne shell prompt in Digital UNIX

Your Comments Are Welcome

We value and appreciate your comments as an Oracle user. As we write, revise, and evaluate our documentation, your opinions are the most important feedback we receive.

You can send comments and suggestions about this manual to the following e-mail address:

infodev@us.oracle.com

If you prefer, you can send letters or faxes containing your comments to the following address:

Server Technologies Documentation Manager

Oracle Corporation

500 Oracle Parkway

Redwood Shores, CA 94065

Fax: (650) 506-7228

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