Optimum Oracle 9i Install for COTS

Anyone,

I am trying to understand what features of 9i get used by Oracle itself to optimize queries and database performance vs which ones require applications to be coded to take advantage of these features.

I work with a CMMS system called Maximo that is a COTS product and it uses Oracle as its back end with a J2EE based front end. Underlying technology is BEA Weblogic and Actuate Web based (IIS) reporting. So the db will act as both OLAP and OLTP. However, system was not programmed with Oracle 9i in mind. Very basic no true RI or advanced feature usage like packages and what not.

I want to know what options I should use when both I install Oracle and when I create a db that will be used as home to this system. Which options does Oracle take over and use itself versus what ones are just added overhead that waste resources.

Items in question:
Oracle Spatial
Oracle Ultra Search
Oracle Data Mining
Oracle OLAP
Example Schema (I always get rid of this one)

What on the Standard Options should be allowed into db?
Oracle JVM
Oracle Intermedia
Oracle Text
Oracle XML DB

Thanks for any help,
David Miller