yum fails after rpm --rebuilddb is run

[Paul Rockwell]

I (foolishly) was playing around with rpm on YDL 3.0, and issued a
rpm --rebuilddb. Since doing that, yum now fails as follows:

[root@linuxppc rpm]# yum update
Gathering package information from servers
Getting headers from: Yellow Dog Linux 3.0 base
Getting headers from: Yellow Dog Linux 3.0 updates
rpmdb: /var/lib/rpm/Packages: unsupported hash version: 8
error: cannot open Packages index using db3 - Invalid argument (22)
Traceback (most recent call last):
  File "/usr/bin/yum", line 44, in ?
    yummain.main(sys.argv[1:])
  File "yummain.py", line 145, in main
  File "clientStuff.py", line 146, in rpmdbNevralLoad
  File "clientStuff.py", line 139, in openrpmdb
NameError: global name 'RpmError' is not defined

I've got rpm-4.1.1-1.8xa installed. It looks like rpm --rebuilddb now
creates rpm databases in a format that yum doesn't understand. A 'file'
of the rpm databases says that they are now Berkeley DB: hash version 8.

Anyone have any ideas how to get yum working again?

- Paul E. Rockwell