Personally, I upgrade using the u*** scripts. However, this is not for everybody. The u0801060.sql script will reside in the 8.1.7 $OH/rdbms/admin directory after you install 8.1.7.

If you use odma, you have to install the 8.1.7 software in a different $ORACLE_HOME. Then, you run odma from the 8.1.7 $OH and it will ask you a bunch of questions and then perform the upgrade. It's really simple.

For large databases, it runs much faster than an export/import.