If when running YUM, you get the following message:

Warning: RPMDB altered outside of yum.

It means at least one package has been install using RPM directly. Consequently, some cache used by YUM are now out-of-sync with the RPMDB.

To sync the cache and get ride of this warning, one juste has to purge YUM’s cache to force its reconstruction next time YUM is ran.

yum clean all

To prevent this situation, use YUM even when installing a local rpm file. Use

yum --nogpgcheck install package-4.6.3.rpm

Instead of

rpm --install --test package-4.6.3.rpm

Note that there is a localinstall option to YUM that is kept for compatibility reasons but really behaves like install.