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If you have existing Oracle-accessing applications on z/OS that were developed with an Oracle Database release before Oracle Database 10g, read this chapter to understand the issues or considerations for those applications. Which issues or considerations apply depend on the applications and on the Oracle Database version with which they have been running.

This chapter assumes that you are migrating from an Oracle version no older than Oracle8i OSDI. If your applications are still running with libraries and components from Oracle8i MPM, or from any older Oracle release, you will need to refer to the Oracle8i OSDI and Oracle9i OS/390-specific documentation for additional application migration considerations.

Migrating from Oracle8i

Client applications built with and using libraries from Oracle8i OSDI will continue to work without changes when run against Oracle Database 10g. They must continue to use the stubs, CMDLOAD and MESG data sets, or (in the case of POSIX shell applications) the ORACLE_HOME structures from the Oracle8i OSDI distribution. You cannot mix these applications with Oracle9i or Oracle Database 10g applications in a multi-task or multi-enclave design (where they would share the same STEPLIB and/or ORA$LIB as Oracle9i or Oracle Database 10g programs). Be aware that all non-POSIX Oracle8i clients in z/OS use the OSDI Network service when accessing a remote Oracle server. You must continue to run an Oracle8i OSDI Network service until all such clients have been migrated.

Migrating from Oracle9i

Applications that were built under Oracle9i will continue to work when run against an Oracle Database 10g server when using the Oracle9i runtime components (such as CMDLOAD and MESG data sets and ORACLE_HOME). In addition, Oracle9i applications will run unmodified using the Oracle Database 10g runtime components. This simplifies migration and is useful in certain situations where multiple programs (possibly mixed Oracle9i and Oracle Database 10g programs) must share one set of runtime components. There are, however, some significant changes in the z/OS Oracle client-side implementation in Oracle Database 10g. Most changes are internal improvements with little or no external manifestation, but some are things you may want to exploit and a few are external behavior changes that could impact existing jobs, scripts, or procedures. Read each of the following sections to determine if there are changes that could affect your applications.