Migration to new instances of Oracle Transparent Gateway for DRDA from an existing installation is straightforward, provided some guidelines are followed.
This chapter provides information that is specific to this release of the Oracle Transparent Gateway for DRDA and includes the following sections:
Migration is the process of transforming an installed version of an Oracle database into a later version (compare this with upgrading). For example, transforming an Oracle8i database into an Oracle9i database is migrating the database. This transformation generally involves running the Oracle migrate (MIG) utility to modify Oracle database control file structures from the format of one version to the format of another version.
Upgrading is the process of transforming an Oracle database from an installed release into a later release of the same version. For example, transforming patch release 8.0.3 into patch release 8.0.4 is upgrading.
Install the new release of the gateway in a separate directory, as outlined in Chapter 4, "Installing the Gateway".
Caution:
Do not install the gateway over a previously existing Gateway installation. Doing so will corrupt the existing installation.In previous releases, the gateway used two gateway initialization files (initsid.gtwboot and initsid.ora), or it used a Startup Shell Script (drdaDB2.sh) and one initialization file (initsid.ora). In this release, all parameters have been migrated into a single gateway initialization file, initsid.ora. Migrating a previous release involves copying the parameters from the initsid.gtwboot or Startup Shell Script into initsid.ora. The format of the parameters can be found in Appendix C, "DRDAESpecific Parameters".
Copy the initsid.ora from the old Gateway instance to the new instance. The parameters in the initsid.ora gateway initialization file have changed format. Refer to "Gateway Initialization File Parameters" in Appendix C, "DRDAESpecific Parameters".
During the migration from older version 4, version 8, or version 9 gateway instances to the latest Oracle Database 10g release, if problems are encountered, then it is always possible to revert to the previous version. Assuming a working version 4 gateway instance exists, change the TNSNAMES.ORA entries from using the Oracle Database 10g gateway instance to the older version 4 instance. Remember to remove the "(HS=)" entry from the Oracle Net connect definition.
Oracle recommends that when you are installing a new release of the gateway and upgrading existing instances, you keep the old gateway home and instance configurations intact and operational, in case there are problems with the upgrade. This will help ensure minimal downtime between changes to different gateway instances.
This release of the Oracle Transparent Gateway for DRDA introduces new and changed initialization parameters if you are migrating from a version 4, version 8, or version 9 gateway to the Oracle Database 10g gateway.
The following section lists new parameters relevant to migration from version 4 gateways.
Parameters introduced in this release of the gateway, listed in the following table, may be added to the gateway initialization file:
DRDA_CACHE_TABLE_DESC
DRDA_GRAPHIC_LIT_CHECK
DRDA_GRAPHIC_PAD_SIZE
DRDA_GRAPHIC_TO_MBCS
DRDA_MBCS_TO_GRAPHIC
DRDA_PROCDESC_STMT
DRDA_PROCDESCPARMS_STMT
DRDA_PROCCALL_MASK
DRDA_FUNCDESC_STMT
DRDA_FUNCDESCPARMS_STMT
DRDA_FUNCCALL_MASK
DRDA_GRAPHIC_CHAR_SIZE
The usage of the following parameters has changed with version 9 of the gateway:
DRDA_CONNECT_PARM
The following table presents a list of parameters that have been renamed with version 9 of the gateway, and their corresponding old names. Refer to Oracle Database Heterogeneous Connectivity Administrator's Guide for more detailed information about these parameters.
Table 14-1 Parameters That Have Been Renamed
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The following parameters are now obsolete. Please remove them from your configuration files:
MODE
SERVER_PATH
DRDA_OVERRIDE_FROM_CODEPAGE
DRDA_OVERRIDE_TO_CODEPAGE
ERROR_LOGGING
ERROR_REPORTING
ERRORTAG
GATEWAY_SID
GROUP_BY_OFF
GTWDEBUG
INCREMENT_CURSORS
DRDA_CALLDESC_STMT
DRDA_CALLDESC_PROC
Part of the normal installation for the gateway involves binding a package and (as an option) installing data dictionary views on the DRDA Server. This release of the gateway (10.2.0.1.0) is compatible with version 4, version 8, and version 9 packages that have been previously bound. The data dictionary views, however, have changed with this release. If you plan to use the data dictionary views that are provided by the gateway, then you must migrate to the new views. Oracle recommends that you install the new views as outlined in Chapter 10, "Configuring the Gateway". If you have changed certain DRDA parameters of the gateway initialization parameters as a result of the migration, then a rebind of the package will be required.
The gateway uses the Heterogeneous Services (HS) facilities of Oracle and Oracle Net. As such, gateway service name entries in tnsnames.ora need a slight modification to tell Oracle Net that the gateway will be using the HS facilities. Refer to "Configuring Oracle Net" for detailed information.