4
Understanding Coexistence and Migration Issues

This chapter describes migration and coexistence issues for SQL*Net version 2.x and Net8. Specific topics discussed are:

• Net8 and SQL*Net Differences

• Migration and Coexistence Overview

• Migration Issues

• Coexistence Issues

Net8 and SQL*Net Differences

When dealing with SQL*Net to Net8 migration and SQL*Net and Net8 coexistence, keep in mind the following features that impact the location and structure of the configuration files:

This Feature...	SQL*Net	Net8
Configuration File Location	SQL*Net stores files in ORACLE_HOME\NETWORK\ADMIN	Net8 stores files in ORACLE_HOME\NET80\ADMIN
Multiple Protocol Support	Multi-Protocol Interchange allows applications in TNS networks to communicate across different protocols.	The Oracle Connection Manager has a multi-protocol support feature which allows client and database servers operating on different protocol stacks to communicate with each other. For more information, see "Configuring Oracle Connection Manager" in Chapter 6, "Configuring the Network".
Configuration Tools	SQL*Net provides: SQL*Net Easy Configuration to create service names Oracle Network Manager for complex configurations	Net8 provides: Oracle Net8 Easy Config to create service names Oracle Net8 Assistant for complex configurations and network administration
External Procedures	n/a	Support for external procedure, a function or procedure written in a third-generation language (3GL) that can be called from PL/SQL code.

Migration and Coexistence Overview

When installing Oracle Networking Products, you have these installation decisions to make:

Installation Decision	Description
Coexistence	Install Net8 into the same Oracle home as your SQL*Net version 2.x.
Migration	Migrate is the process of moving from SQL*Net version 2.x to Net8. Migration involves installing Net8 and de-installing SQL*Net version 2.x.

Additional Information: See Chapter 7, "Migrating and Upgrading," of your Getting Started guide.

Migration and Coexistence Considerations

This section discusses:

• Oracle7 Client Connections to Oracle8 Databases

• Oracle8 Client Connections to Oracle7 Databases

• Oracle Names

Oracle7 Client Connections to Oracle8 Databases

As the diagram below depicts, an Oracle7 Client requires SQL*Net Client, and an Oracle Server requires Net8 Server. When the client and server are on the same machine, both SQL*Net Client and Net8 Server are required.

Consider the following questions for your own environment.

• Will my third party Oracle7 applications be able to take advantage of Net8 features?

  No. You must rebuild or upgrade applications to work with Net8 libraries.

• Do my Oracle7 clients require Net8 Client to connect to a remote Oracle8 database?

  No. If an Oracle7 client needs to connect to a remote Oracle8 database, only SQL*Net Client version 2.x has to be configured on the Oracle7 client. Net8 is backward compatible with SQL*Net version 2.x. The only limitation is that the new network features available with Net8 are unavailable with this connection type.

• Do my Oracle7 clients require Net8 Client to connect to a local Oracle8 database?

  Yes. If the Oracle7 client needs to connect to a local Oracle8 database, you have SQL*Net Client version 2.x, Net8 Client, and Net8 Server in the Oracle7 client Oracle home. Note that Net8 Client and Net8 Server are already installed during the installation of Oracle8 Enterprise Edition or Oracle8.

  If you are using Oracle7 release 7.3.4 and SQL*Net release 2.3.4, you can connect to the Oracle8 database without specifying a service name. Oracle7 client automatically uses the Bequeath Protocol Adapter when connecting to an Oracle8 database.

  If you are using Oracle7 release 7.3.3 (or lower) and SQL*Net release 2.3.3 (or lower), you need to create a service name using SQL*Net Easy Configuration or Oracle Network Manager in the SQL*Net Client version 2.x TNSNAMES.ORA file. Ensure you specify this service name in the connect string when connecting to the Oracle8 database.

  The Bequeath Protocol Adapter is not supported when connecting from an Oracle7 client (release 7.3.3 or lower) to an Oracle8 database. The figure below gives an example of this network configuration:

Oracle8 Client Connections to Oracle7 Databases

An Oracle8 Client requires Net8 Client, and an Oracle7 Server requires SQL*Net Server. When the client and server are on the same machine, both Net8 Client and SQL*Net Server are required.

Consider the following questions for your own environment.

• Do my Oracle8 clients require SQL*Net Client version 2.x to connect to a remote Oracle7 database?

  No. If an Oracle8 client needs to connect to a remote Oracle7 database, only Net8 Client needs to be configured on the Oracle8 client. SQL*Net version 2.x is upwards compatible with Net8. The only limitation is that the new network features available with Net8 are unavailable with this connection type.

• Do my Oracle8 clients require SQL*Net Client version 2.x to connect to a local Oracle7 database?

  Yes. If the Oracle8 client needs to connect to a local Oracle7 database, you need to both SQL*Net Server version 2.x and Net8 Client in the Oracle8 client Oracle home. Note that the Oracle8 client uses the Bequeath protocol adapter by default to connect to an Oracle7 database. The figure below gives an example of this network configuration.

Oracle Names

If you are migrate all or part of your network to Net8, and you add or upgrade any version 8 Names Servers to an existing network, you should upgrade all the Names Servers in the region to version 8. There should be at least two Names Servers, for fault-tolerance.

• Can my Oracle7 clients use Oracle Names version 8 to resolve service names?

  Yes.

• Can my Oracle7 client then use the connect string returned form Oracle Names version 8 to connect to an Oracle7 or Oracle8 database?

  Yes, if the connect string was specified correctly when it was entered into Oracle Names. In other words, if the connect string worked from a TNSNAMES.ORA file, it will work from Oracle Names.

  Net8 Client is not available for Windows 3.1x, however, SQL*Net version 2 clients can be used to connect to Oracle8 databases.

Migration Issues

SQL*Net version 2.x clients should migrate to Net8 only when their client applications migrate to Oracle8.

Installation

If you are migrating from SQL*Net version 2.x to Net8, Oracle Installer automatically performs these tasks:

1. Configuration files are copied from ORACLE_HOME\NETWORK\ADMIN and saved into ORACLE_HOME\NET80\ADMIN.

1. SQL*Net version 2.x network listener is stopped. The startup type is changed from Automatic to Manual (Windows NT Control Panel).

2. Net8 network listener is setup as Automatic startup and is started.

3. Entries are added to the TNSNAMES.ORA and LISTENER.ORA file for external procedures, if the entries are not already present.

When migrating from Oracle7 Server release 7.3.x to Oracle8 release 8.0.4, install the appropriate version of SQL*Net for the server before using Oracle Data Migration Assistant. Migration will be unsuccessful if you do not install the appropriate versions of SQL*Net

Migrating from...	Install...
Oracle7 release 7.3.2 to Oracle8	SQL*Net version 2.3.2.1.12
Oracle7 release 7.3.3 to Oracle8	SQL*Net version 2.3.3.0.3 To install SQL*Net version 2.3.2.1.12 or 2.3.3.0.3 Start Oracle Installer from the CD-ROM. See the CD insert. Answer questions about language and Oracle home directory location. Select Custom Installation. The Software Asset Manager window appears. Click From... Navigate to \PATCHES\SQLNET\232112\NT_X86\INSTALL on the CD-ROM if you want to install SQL*Net version 2.3.2.1.12. Navigate to \PATCHES\SQLNET\23303\NT_X86\INSTALL if you want to install SQL*Net version 2.3.3.0.3. Select SQL*Net Server 2.3.2.1.12 and SQL*Net Client 2.3.2.1.12 if you want to install SQL*Net version 2.3.2.1.12. Select SQL*Net Server 2.3.3.0.3 and SQL*Net Client 2.3.3.0.3 if you want to install SQL*Net version 2.3.3.0.3. Click Install. A window appears showing the progress of the installation. After installation is complete, a message appears confirming the installation. Click Exit to exit Oracle Installer.

File Names

In Net8, executables (.EXE files) and dynamic link libraries (.DLL files) are contained in the directory:

ORACLE_HOME\BIN

File names in Net8 typically have an 80 appended to the corresponding name in SQL*Net version 2.x. This suffix prevents conflict with SQL*Net version 2.x files.

Service Names

Net8 service names differ from SQL*Net version 2.x service names:

Net8 Component	SQL*Net V2 Name	Net8 Name
Listener	OracleTNSListener	OracleHOME_NAMETNSListener80
Oracle Names	OracleNamesService	OracleHOME_NAMENamesService80
Oracle Connection Manager	n/a	OracleHOME_NAMECMAdminService80 OracleHOME_NAMECMANService80
Client Cache	n/a	OracleHOME_NAMEClientCache80

Coexistence Issues

SQL*Net version 2.x can coexist with Net8 on the same machine in the same Oracle home directory.

WARNING: For co-existence of Net8 and SQL*Net version 2.x, you must install Net8 into the same Oracle home directory as SQL*Net version 2.x. Installing Net8 into a different Oracle home directory will disable the products located in the old Oracle home directory.

Installation

If you are not migrating, and you are installing Net8 onto the same machine where SQL*Net version 2.x exists, Oracle Installer automatically performs these tasks to enable coexistence:

1. Configuration files are copied from ORACLE_HOME\NETWORK\ADMIN and saved into ORACLE_HOME\NET80\ADMIN.

1. The Net8 network listener is setup as Manual startup. The network listener is not started.

2. Entries are added to the TNSNAMES.ORA and LISTENER.ORA file for external procedures, if the entries are not already present.

Listener

To use the version 8 network listener, you may need to change your network configuration on either the SQL*Net version 2.x or Net8 configurations to prevent conflict. For example, you may need to change:

• Port number on a TCP/IP network

• Service name on an SPX network

• Pipe name on a Named Pipes network

• KEY for IPC connection

You may also need to start the Net8 network listener, and change the status to Automatic startup, depending upon your network needs. If you make changes to the network listener, you must make changes to client configuration files to ensure that clients can connect to the network listener.

Configuration Files

SQL*Net version 2.x will use configuration files from ORACLE_HOME\NETWORK\ADMIN, while Net8 will use files from ORACLE_HOME\NET80\ADMIN by default. If you want both SQL*Net and Net8 to use configuration files from the same directory, set the registry variable TNS_ADMIN.

Additional Information: See Appendix B, "Modifying and Adding Configuration Parameters", for more information.

Oracle Network Products Compatibility

Table 4-1 shows the Oracle Network Products releases that are compatible with that Oracle7 database and Oracle8 database releases.

Note: A client and server or two servers running different versions of Oracle Network Products connect successfully. The functionality, however, defaults to the lower version.

Table 4-1 Compatible Releases

Database Release	7.1.4	7.1.5	7.1.6	7.2.2	7.2.3	7.3.2	7.3.3	7.3.4	8.0.3	8.0.4
SQL*Net	2.1.4	2.1.5	2.1.6	2.2.2	2.2.3	2.3.2	2.3.3	2.3.4	n/a	n/a
Names Server	1.0	1.0	1.0	1.1	2.0	2.0.2	2.0.3	2.0.4	8.0.3	8.0.4
Advanced Networking Option	n/a	n/a	n/a	n/a	n/a	2.3.2	2.3.3	2.3.4	8.0.3	8.0.4
Secure Network Services1	1.0.1	1.0.2	1.0.3	1.1	2.0	n/a	n/a	n/a	n/a	n/a
Net8	n/a	n/a	n/a	n/a	n/a	n/a	n/a	n/a	8.0.3	8.0.4

1 The functionality of Secure Network Services and SQL*Net/DCE are now included in the Oracle Advanced Networking Option.

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