Upgrading Oracle Database & Remedy's Action Request System 1

I would recommend looking at it as two separate operations, even if you perform them at the same time. Upgrading Oracle should have no impact on Remedy (assuming you keep the same names in tnsnames, etc). Bring Remedy down, then perform the Oracle upgrade. When that's all done, bring Remedy up and check it all out. After you're sure that's all fine, then do the Remedy upgrade.

Have you performed you upgrade yet?

Each upgrade should be handled separately.

Check out this link for compatibility of Remedy versions
with ORACLE versions:

ORACLE:
Upgrading ORACLE from 8.1.6 to 8.1.7 will not require a dump and reload of data - it is a binary upgrade. This is not considered a major upgrade.

REMEDY:
Depending on your server, ARS 5.0.1 supports ORACLE 8.1.7. It doesnt say if 8.1.6 is supported so assume it does not.
If you are running ARS 4.5.1, I also assume you cannot use ORACLE 8.1.7 (at least it doesnt say you can, or cannot)
Given this, it looks like you would have to upgrade simultaneously, which I like to avoid becuase if something goes wrong, you have no idea what is going on and backing-out is a nightmare.

One possibility around all this is upgrading to ARS4.5.2, which supports ORACLE 8.1.7. This should cause little/no impact to your users. Next, upgrade to ORACLE 8.1.7 (perhaps a week later) which should also cause no user impact.

After some period of time (weeks ?) consider upgrade to ARS5.0.1, which will most likely cause user impact

Don't forget to judge if the client tools have toalso be upgraded when you upgrade ARS (see compatibility matrix)

Tom