when I have installing Oracle10.2 on ubuntu8.04,appear system check error!

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 (2)
error: cannot open Packages database in /var/lib/rpm
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 (2)
error: cannot open Packages database in /var/lib/rpm

and I type:
mkdir /var/lib/rpm
rpm --initdb

but appear new problem:

rpm: To install rpm packages on Debian systems, use alien. See README.Debian.
error: cannot open Name index using db3 - No such file or directory (2)

how to solved? help me!

I'm not sure what procedure you're following to get those errors, but I recommend looking at http://www.puschitz.com/. I've used the docs there for installs on Redhat, Fedora and Slackware boxes.