loading oracle express onto ubuntu

Oracle seems to offer two variants of its express package for linux, one is "rpm" the other "debian". I chose to download the "rpm" one but when trying to install on ubuntu using the command
"rpm -ivh oracle-xe-10.2.0.1-1.0.i386.rpm" I get 3 messages:
"rpm: to install rpm packages on Debian systems use alien, see README.Debian"
"error: cannot open Packages index using db3 - no such file or directory"
"error: cannot open Packages database in /var/lib/rpm"

Has anyone tried this before me, and got it to work?