Jive Upgrade essentially involves change in database structure. It is not possible to run Jive 9 pointing to Jive 7 database schema.
Typically I completely install Jive to the new version, then test it to make sure everything is working. Once that's done, you can nuke the newly-created dB and copy your Jive 7 data over. On startup, Jive will detect that the dB version is old and kick you into the upgrade console.
Completely installing and successfully testing the higher version eliminates a lot of problems during the actual data upgrade. That way, you don't have to worry during upgrade that errors you are seeing are environmental, and can be sure they're data-related.
Hope this helps,