Preface

Oracle9i Application Developer's Guide - Object-Relational Features describes how to use the object-relational features of the Oracle Server, Release 2.0.2. Information in this guide applies to versions of the Oracle Server that run on all platforms, and does not include system-specific information.

This preface contains these topics:

Audience

Oracle9i Application Developer's Guide - Object-Relational Features is intended for programmers developing new applications or converting existing applications to run in the Oracle environment. The object-relational features are often used in multimedia, Geographic Information Systems (GIS), and similar applications that deal with complex data. The object views feature can be valuable when writing new applications on top of an existing relational schema.

This guide 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.

Organization

This document contains:

Chapter 1, "Introduction to Oracle Objects"

Introduces the key features and explains the advantages of the object-relational model.

Chapter 2, "Basic Components of Oracle Objects"

Explains the basic concepts and terminology that you need to work with Oracle Objects.

Chapter 3, "Object Support in Oracle Programming Environments"

Summarizes the object-relational features in SQL and PL/SQL; Oracle Call Interface (OCI); Pro*C/C++; Oracle Objects For OLE; and Java, JDBC, and Oracle SQLJ. The information in this chapter is high-level, for education and planning. The following chapters explain how to use the object-relational features in greater detail.

Chapter 4, "Managing Oracle Objects"

Explains how to perform essential operations with objects and object types.

Chapter 5, "Applying an Object Model to Relational Data"

Explains object views, which allow you to develop object-oriented applications without changing the underlying relational schema.

Chapter 6, "Advanced Topics for Oracle Objects"

Discusses features that you might need to manage storage and performance as you scale up an object-oriented application.

Chapter 7, "Frequently Asked Questions About Using Oracle Objects"

Provides helpful hints for people getting started with object-oriented programming, or coming to Oracle with a background in some other database system or object-oriented language.

Chapter 8, "Design Considerations for Oracle Objects"

Explains the implementation and performance characteristics of Oracle's object-relational model.

Chapter 9, "A Sample Application Using Object-Relational Features"

Demonstrates how a relational program can be rewritten as an object-oriented one, schema and all.

Related Documentation

For more information, see these Oracle resources:

PL/SQL User's Guide and Reference to learn PL/SQL and to get a complete description of this high-level programming language, which is Oracle Corporation's procedural extension to SQL
Oracle9i Application Developer's Guide - Fundamentals for general information about developing applications
Oracle9i JDBC Developer's Guide and Reference and Oracle9i Java Stored Procedures Developer's Guide to use Oracle's object-relational features through Java
Oracle Call Interface Programmer's Guide describes how to use the the Oracle Call Interface (OCI) to build third-generation language (3GL) applications that access the Oracle Server
Pro*C/C++ Precompiler Programmer's Guide for information on Oracle's Pro* series of precompilers, which allow you to embed SQL and PL/SQL in 3GL application programs written in Ada, C, C++, COBOL, or FORTRAN
Oracle Developer/2000 is a cooperative development environment that provides several tools including a form builder, reporting tools, and a debugging environment for PL/SQL. If you use Developer/2000, then refer to the appropriate Oracle Tools documentation.
Oracle9i SQL Reference and Oracle9i Database Administrator's Guide for information on SQL
Oracle9i Database Concepts for information on basic Oracle concepts

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 Oracle9i Sample Schemas for information on how these schemas were created and how you can use them yourself.

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Conventions

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

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.	Oracle9i 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 `U``old_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;

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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

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