You have several options to upgrade your existing databases in Oracle 8i or 9i to Oracle Database 10g. We will skim over the various steps used for the manual migration process as well as direct migration steps for the different versions. Before you plan for any upgrade process, make sure that you have the latest backup of your database on media and keep a database copy on another identical machine. This copy database will be there for you to point your applications to in the event something goes wrong during the upgrade process and you experience significant downtime.
More details of the upgrade processes are mentioned in Oracle Database Upgrade Guide 10g.
Is Export/Import a Good Option?
The traditional export/import ...