4
Understanding Coexistence and Migration Issues

This chapter describes migration and coexistence issues for SQL*Net release 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".
Configuration Tools	SQL*Net provides: SQL*Net Easy Configuration to create service names Oracle Network Manager for complex configurations	Net8 provides: Net8 Easy Configuration Tool to create service names Oracle Net8 Assistant for complex configurations and network administration
External Procedures	Not Applicable	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 release 2.x.
Migration	Migration is the process of moving from SQL*Net release 2.x to Net8. Migration involves installing Net8 and de-installing SQL*Net release 2.x.

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 computer, 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 release 2.x has to be configured on the Oracle7 client. Net8 is backward compatible with SQL*Net release 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 should have SQL*Net Client release 2.x, Net8 Client, and Net8 Server on the same system. SQL*Net Client 2.x needs to be in the Oracle7 Client Oracle home, while the Net8 Client and Server should be in the Oracle8 Oracle home. Note that Net8 Client and Net8 Server are already installed during the installation of Oracle8/TM 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 release 2.x TNSNAMES.ORA file. Ensure you specify this service name in the connect string when connecting to the Oracle8 database.

  The service can use any protocol adapter installed except the Bequeath Protocol Adapter. 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 computer, 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 release 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 release 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 release 2.x to connect to a local Oracle7 database?

  Yes. If the Oracle8 client needs to connect to a local Oracle7 database, you need both SQL*Net Server release 2.x and Net8 Client on the same system. Net8 Client needs to be in the Oracle8 Oracle home, while SQL*Net 2.x should be in the Oracle7 Oracle home. Note that the Oracle8 client uses the Bequeath protocol adapter by default to connect to an Oracle7 database.

Oracle Names

If you migrate all or part of your network to Net8, and you add or upgrade any release 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 release 2.x clients should migrate to Net8 only when their client applications migrate to Oracle8.

Installation

If you are migrating from SQL*Net release 2.x to Net8 in the same Oracle home, Oracle Installer automatically performs these tasks:

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

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

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

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

When migrating from Oracle7 Server release 7.3.x to Oracle8 release 8.0.6, 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.

You do not need to install a SQL*Net patch when migrating from Oracle7 release 7.3.4 to Oracle8 release 8.0.6.

Migrating from...	Install...
Oracle7 release 7.3.2.x to Oracle8	SQL*Net release 2.3.2.1.4 SQL*Net patch 2.3.2.1.12 Note: If you do not have SQL*Net release 2.3.2.1.4 on your system, you must install it before installing SQL*Net patch 2.3.2.1.12. SQL*Net release 2.3.2.1.4 is not available on the release 8.0.6 CD-ROM. You must install it from the release 7.3.2 CD-ROM.
Oracle7 release 7.3.3.x to Oracle8	SQL*Net release 2.3.3.0.3
	To install SQL*Net patch 2.3.2.1.12 or patch 2.3.3.0.3 Start Oracle Installer from the CD-ROM. See Oracle8 Enterprise Edition Installation Release 8.0.6 for Windows NT for complete installation instructions. 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 on the CD-ROM if you want to install SQL*Net patch 2.3.2.1.12. Navigate to \PATCHES\SQLNET\23303 if you want to install SQL*Net patch 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 patch 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 patch 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 release 2.x. This suffix prevents conflict with SQL*Net release 2.x files.

Service Names

Net8 service names differ from SQL*Net release 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
SNMP	n/a	OracleSNMPPeerMasterAgent
SNMP	n/a	OracleSNMPPeerEncapsulator

Migrating a Database to a New Oracle Home

When a database is migrated from one Oracle home to another Oracle home, the SID of the migrated database is added to the SID_LIST section of the LISTENER.ORA file located in the ORACLE_HOME\NET80\ADMIN directory for the second Oracle home, but the SID for the first Oracle home still remains in the LISTENER.ORA file for the first Oracle home. This entry can cause a conflict in the SIDs if you need to bring up both the listeners. You should either:

• ensure that the listener for the first Oracle home is not brought up

or

• remove the SID from the SID_LIST section of the LISTENER.ORA in the first Oracle home.

Coexistence Issues

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

Installation

If you are not migrating, and you are installing Net8 onto the same computer where SQL*Net release 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.

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

3. 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 release 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.

One Listener Supporting Multiple Oracle Homes

You can use one listener for spawning databases for multiple Oracle homes. You only need to add all the System Identifiers (SIDs) to the SID_LIST section in the ORACLE_HOME\NET80\ADMIN\LISTENER.ORA file. Since the SID is unique on a system across different Oracle homes, the listener can spawn the database thread for a specific SID in the correct Oracle home, and the ORACLE_HOME parameter (used in UNIX environments only) is not needed in the LISTENER.ORA.

You can use release 8.0.6 listeners to spawn release 8.0.6 or 7.3.x databases. In a mixed environment, however, you cannot enable the use of shared sockets. Oracle Corporation recommends using different listeners for release 8.0.4, 8.0.5 and 8.0.6 databases.

There are some restrictions in using release 8.0.6 listeners to spawn release 8.0.4, 8.0.5 and 8.0.6 databases. These restrictions include:

• Since release 8.0.4 only supports process mode external procedures, you should enable process mode external procedures for release 8.0.5 and 8.0.6. Releases 8.0.5 and 8.0.6 support both process and thread external procedures.

• You must install the 8.0.4.0.3 (or later) patch for Net8.

• You cannot enable the use of shared sockets.

Configuration Files

SQL*Net release 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 on setting TNS_ADMIN.