Understanding SQL*Net
Preface
Purpose
Understanding SQL*Net provides the information you need to understand and use the SQL*Net release 2.3 product. SQL*Net allows Oracle tools and applications to access, manipulate, share, and store data in Oracle databases residing on remote servers. In addition, SQL*Net enables data access between multiple database servers. This guide describes:
- an overview of SQL*Net version 2 and later
- a detailed description of the SQL*Net release 2.3 architecture
- what to consider when upgrading from SQL*Net version 1
- what to consider when upgrading from an earlier release of SQL*Net version 2
- how to use the network listener
- how to use a SQL*Net version 2 client
- important concepts about using externally identified logins
- a description of SQL*Net-related features of the Oracle7 Server
- how to use SQL*Net in conjunction with other Oracle network products
Note: This manual contains examples and figures that refer to specific machine types, network protocols, and operating systems. These references are examples of possible configurations and are not representative of all configurations.
Audience
The information in this manual is intended primarily for network or database administrators (DBAs). This guide is also for anyone who wants to understand how SQL*Net release 2.3 works.
Documentation Set
Use this guide in conjunction with the other manuals in the Oracle network products documentation set. This set consists of manuals that help you to set up an integrated, heterogeneous network and to use the applications and services provided. The documentation consists of the following manuals:
- Oracle operating system-specific manuals include installation instructions for the networking products on your platform, and describe the Oracle Protocol Adapters, including:
- protocol terms and concepts
- protocol-specific parameters
Refer to this book for installation instructions and other information that is platform or operating system specific.
- Understanding SQL*Net (this manual)
Describes SQL*Net release 2.3, including:
- new features in SQL*Net release 2.3
- planning your SQL*Net release 2.3 network
- using SQL*Net release 2.3
Refer to this book to understand how SQL*Net works, and how to use it after it is installed and configured.
- Oracle Network Manager Administrator's Guide
Describes the tool that creates the configuration files for the Oracle networking products, including:
- SQL*Net release 2.1 and later
- Oracle MultiProtocol Interchange
- Oracle Native Naming Adapters
Use this book when you are ready to configure the SQL*Net network.
- Oracle MultiProtocol Interchange Administrator's Guide
Describes the Oracle MultiProtocol Interchange, including:
- the purpose and function of the Interchange
- using the Interchange to navigate connections over a network
- client choices for accessing the Interchange
- using the Interchange in a network
Refer to this book for information on configuration parameters and how to use the Interchange after it is installed and configured.
- Oracle Names Administrator's Guide
Describes the Oracle Names product, including:
- the purpose and function of Oracle Names
- types of network naming schemes
- configuration requirements for Oracle Names
- the SQL*Net Dynamic Discovery Option (DDO) for self-registering network services
Refer to this manual to learn how Oracle Names works, and how to use it after it is installed and configured.
- Secure Network Services Administrator's Guide
Describes the encryption, checksuming, and enhanced user authentication features that add security to the Oracle network , including:
- an overview of the Secure Network Services product
- the purpose and effectiveness of the security feature
- how to enable the security features using Oracle Network Manager
Refer to this manual to learn how Secure Network Services works, and how to configure encryption, checksumming and support for enhanced authenticationwith Network Manager.
Note: Secure Network Services versions 1 and 1.1 include encryption and checksumming; version 2. also includes support for enhanced authentication.
- Oracle SNMP Support Reference Guide
Describes the Oracle SNMP Support feature, including
- benefits, basic terms, and components of the feature, and a general overview of Oracle SNMP support for the Oracle7 Server, listener, Oracle MultiProtocol Interchange and Oracle Names.
- an overview of the Oracle MIBs that provide Oracle SNMP Support, as well as information to help you read and interpret public and private MIB variables
- guidelines to assist in developing management applications for Oracle products based on Oracle MIBs.
- reading and interpreting the MIB variables that support monitoring of the Oracle7 Server, and the listener, Oracle MultiProtocol Interchange, and Oracle Names network services
Refer to this manual to learn how SNMP support works, and how to use it after it is installed and configured.
- Oracle Network Products Troubleshooting Guide
Contains error and diagnostic information, including:
- information about how to use the diagnostic features of Oracle network products. These include logging, tracing, Audit Trail, Trace Route, and the Client Status Monitor.
- the error messages and informational messages that may occur during network processing
Use this book for troubleshooting help.
- Release notes for this release of SQL*Net and Oracle Names.
How This Manual Is Organized
Understanding SQL*Net consists of six chapters and four appendices.
Chapter 1 - Introduction to SQL*Net
This chapter is an introduction to SQL*Net version 2 and how SQL*Net connections are established. It describes the general features of SQL*Net, and highlights the features new to this release.
Chapter 2 - SQL*Net Version 2 Architecture
This chapter explains the SQL*Net architecture and describes how the components of a SQL*Net network work together. It explains how connection requests to a multi-threaded server are handled, and explains how listener load balancing works.
Chapter 3 - Network Layout and Naming Issues
This chapter outlines considerations for planning a version 2 installation. It discusses the relationships of the network products, and discusses how to plan your network for future growth and flexibility.
Chapter 4 - Migrating from an Earlier Version of SQL*Net
This chapter describes how to migrate from a SQL*Net version 1 installation or from SQL*Net version 2. It describes how to upgrade from SQL*Net version 1 and manage coexistence of two versions of SQL*Net during the migration. It also describes migration issues in a mixed environment of various SQL*Net version 2 releases.
Chapter 5 - Using SQL*Net
This chapter explains how SQL*Net is used after it has been configured. The chapter describes how to start and test the network, how to use the Listener Control Utility, how to control the clients, how to initiate connections through various tools, and how to use some distributed database features.
Chapter 6 - Configuring Oracle SNMP Support
This chapter provides a general overview of tasks to perform to configure Oracle SNMP Support for the Oracle7 Server, listener, Oracle Names, and Interchange. For detailed information on Management Information Base (MIB) variables used in the Oracle SNMP Support feature see the Oracle SNMP Support Reference Guide.
Appendix A - Contents of Configuration Files
This appendix describes the contents of the configuration files for SQL*Net: TNSNAMES.ORA, LISTENER.ORA, SQLNET.ORA, and PROTOCOL.ORA. (The configuration files associated with the MultiProtocol Interchange and Oracle Names are described in the Oracle MultiProtocol Interchange Administrator's Guide and the Oracle Names Administrator's Guide, respectively.)
Appendix B - Syntax Rules for Configuration Files
This appendix describes the syntax rules for configuration files. Although Oracle Network Manager creates the configuration files, this information might be useful if you need to manually edit or troubleshoot the files.
Appendix C - Common Error Messages
This appendix describes the most common causes of problems while configuring or using SQL*Net release 2.x, and discusses some of the common error messages and how to resolve them.
Appendix D - SQL*Net OPEN
This appendix describes the application programming interface (API) to SQL*Net. Using SQL*Net OPEN, programmers can develop non-database applications that take advantage of Oracle's complete set of networking products.
Related Publications
In addition to this guide and the other Oracle network product manuals, you may want to refer to the following documents published by Oracle Corporation:
- SQL Language Reference Manual
- Oracle operating system-specific manuals for your platforms
Notational Conventions
The following syntax conventions are used in this manual:
| Monospace normal | Monospace shows what displays on the computer screen or contains text you need to enter exactly as shown. |
| Monospace italics | Monospace in italics represents a variable. Substitute an appropriate value. |
| [ ] | Brackets enclose optional items. Do not enter the brackets. |
| ( ) | Parentheses enclose many transparent network substrate (TNS) keyword-value pairs. They must be entered as shown; for example, (KEYWORD=value). |
| | | A vertical bar represents a choice of two or more options. You must enter one of the options. Do not enter the vertical bar. |
| Punctuation | Punctuation other than brackets and vertical bars must be entered as shown. |
| UPPERCASE | Uppercase characters within the text represent command names, filenames, and directory names. |
Note: Some operating systems are case sensitive. Although our convention is to present command names, filenames, and directory names in uppercase, that does not necessarily mean that they should be in uppercase on your platforms.
Your Comments Are Welcome
We value and appreciate your comments as an Oracle products user. As we write, revise, and evaluate our work, your opinions are the most important input we receive. At the back of this manual is a Reader's Comment Form; we encourage you to use this form to tell us what you like and dislike about this (or other) Oracle manuals. If the form is gone, or you would like to contact us, please use the following address:
Oracle Network Products Documentation Manager
Oracle Corporation
500 Oracle Parkway
Box 659410
Redwood Shores, CA 94065