Upgrading to Oracle Database 10g, concluded

Using Export and Import

Export and Import provide you with an indirect method for the upgrade. You can create an Oracle 10g database alongside your existing database and use Export and Import to move data from the old database to the new database. When the movement of the data is complete, you will need to point your applications to connect to the new database instead of the old database. You will also need to update any configuration files, version-specific scripts, and the networking configuration files (tnsnames.ora and listener.ora) to point to the new database.

Export and Import Versions to Use

When you create an Export dump file via the Export utility, that file can be imported into all later releases of Oracle. Export dump files are not backward compatible, so if you ever need to revert to an earlier version of Oracle, you will need to carefully select the version of Export and Import used. The following table shows the versions of the Export and Import executables you should use when going between versions of Oracle:

Note that when you are exporting in order to downgrade your database release, you should use the older version of the Export utility to minimize compatibility problems. You may still encounter compatibility problems if the newer version of the database uses new features (such as new datatypes) that the old version will not support.