can an RPM package query the RPM database?

[Cameron Scott ICM N MC MI SI 6 <Scott Cameron icn siemens de>]

Hi again :)
Does anyone know if an RPM package can query the RPM database while
installing? 
As a post install step I am trying to find the prefix path another package
was installed under by running:
rpm -q <package_name> --queryformat '%{INSTALLPREFIX}'

but I get the following message: 
cannot get shared lock on database 
rpmQuery: rpmdbOpen() failed 

Does anyone know a way around this? 


I searched the archive on RedHat but found only this entry - with no
replies:
http://www.redhat.com/mailing-lists/rpm-list/msg00771.html


Cheers,
Scotty