Preface

This guide describes database features that support applications using Large Object (LOB) datatypes. The information in this guide applies to all platforms and does not include system-specific information.

This preface contains these topics:

Feature Coverage and Availability

Oracle Database Application Developer's Guide - Large Objects contains information that describes the features and functionality of Oracle Database 10g.

What You Need To Use LOBs

The database includes all of the resources you need to use LOBs in your application; however, there are some restrictions on how you can use LOBs as described in the following:

See Also:

Audience

Oracle Database Application Developer's Guide - Large Objects is intended for programmers developing new applications that use LOBs, as well as those who have already implemented this technology and now want to take advantage of new features.

The increasing importance of multimedia data as well as unstructured data has led to this topic being presented as an independent volume within the Oracle Application Developers documentation set.

Organization

This guide, Oracle Database Application Developer's Guide - Large Objects, is organized as follows:

Part I, "Getting Started"

This part gives introductory information and explains concepts that you must be familiar with to use LOBs in your application.

Chapter 1, "Introduction to Large Objects"

This chapter gives an introduction to LOB datatypes and describes the kinds of applications in which LOBs are useful.

Chapter 2, "Working with LOBs"

This chapter gives guidelines on working with LOB instances in your application and the database.

Chapter 3, "Managing LOBs: Database Administration"

This chapter describes database administration tasks required to setup and use databases with LOBs. Issues that application developers and database administrators must coordinate on are described.

Part II, "Application Design"

This part covers application design issues for applications that use LOBs.

Chapter 4, "LOBs in Tables"

This chapter describes how to create basic tables that contain LOB columns and gives general guidelines on selecting the best table architecture for your application.

Chapter 5, "Advanced Design Considerations"

This chapter describes more advanced application and database design issues that you may encounter when using LOBs in your application such as: buffering, caching, locators, transactions, and supersized LOBs.

Chapter 6, "Overview of Supplied LOB APIs"

This chapter gives an overview of APIs supplied with the database for using LOBs in applications.

Chapter 7, "Performance Guidelines"

This chapter discusses performance issues you should consider when designing applications that use LOBs.

Part III, "SQL Access to LOBs"

This part describes SQL usage with LOB datatypes in the SQL and PL/SQL environments.

Chapter 8, "DDL and DML Statements with LOBs"

This chapter discusses DDL and DML statements for common tasks performed on tables with LOB columns.

Chapter 9, "SQL Semantics and LOBs"

This chapter describes SQL semantics support for LOB datatypes.

Chapter 10, "PL/SQL Semantics for LOBs"

This chapter describes PL/SQL semantics support for LOB datatypes.

Chapter 11, "Migrating Table Columns from LONGs to LOBs"

This chapter describes techniques for migrating data in tables that use the LONG datatype to LOB columns.

Part IV, "Using LOB APIs"

This part gives details on LOB APIs supplied with the database.

Chapter 12, "Operations Specific to Persistent and Temporary LOBs"

This chapter describes APIs and procedures that vary depending on whether they are performed on persistent or temporary LOB instances.

Chapter 13, "Data Interface for Persistent LOBs"

This chapter describes the data interface for persistent LOBs.

Chapter 14, "LOB APIs for Basic Operations"

This chapter describes LOB APIs for operations that can be used to operate on either persistent LOB or temporary LOB instances.

Chapter 15, "LOB APIs for BFILE Operations"

This chapter describes LOB APIs that are used exclusively with BFILEs.

Appendix A, "LOB Demonstration Files"

This appendix lists and describes sample code included in this book for demonstration purposes.

Glossary

Defines terms used in discussions about LOBs.

Related Documents

For more information, see the following manuals:

PL/SQL Packages and Types Reference: Use this book to learn PL/SQL and to get a complete description of this high-level programming language, which is a procedural extension to SQL.
Oracle Call Interface Programmer's Guide: Describes Oracle Call Interface (OCI). You can use OCI to build third-generation language (3GL) applications in C or C++ that access Oracle Server.
Oracle C++ Call Interface Programmer's Guide
Pro*C/C++ Programmer's Guide: Oracle Corporation also provides the Pro* series of precompilers, which allow you to embed SQL and PL/SQL in your application programs.
Pro*COBOL Programmer's Guide: The Pro*COBOL precompiler enables you to embed SQL and PL/SQL in your COBOL programs for access to Oracle Server.
Programmer's Guide to the Oracle Precompilers and Pro*Fortran Supplement to the Oracle Precompilers Guide: Use these manuals for Fortran precompiler programming to access Oracle Server.
Java: Oracle Database offers the opportunity of working with Java in the database. The Oracle Java documentation set includes the following:

Oracle Database error message documentation is only available in HTML. If you only have access to the Oracle Documentation CD, you can browse the error messages by range. Once you find the specific range, use your browser "find in page" feature to locate the specific message. When connected to the Internet, you can search for a specific error message using the error message search feature of the Oracle online documentation.

Multimedia

You can access the Oracle development environment for multimedia technology in a number of different ways.

To build self-contained applications that integrate with the database, you can learn about how to use the Oracle extensibility framework in Oracle Data Cartridge Developer's Guide
To use the Oracle interMedia applications, refer to the following:

Basic References

For SQL information, see the Oracle Database SQL Reference and Oracle Database Administrator's Guide
For information about using LOBs with Oracle XML DB, refer to Oracle XML DB Developer's Guide
For information about Oracle XML SQL with LOB data, refer to Oracle Database Advanced Replication
For basic Oracle concepts, see Oracle Database Concepts.
For information on using Oracle Data Pump, SQL*Loader, and other database utilities, see Oracle Database Utilities

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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

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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.	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 monospace (fixed-width font) italic`	Lowercase monospace italic 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

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