Currently, the File based RC assumes that the tuple LFN,PFN is a unique entry and does not take the pool attribute into consideration.

this prevents LIGO from having entries with the same file URL's for different sites

e.g this is not allowed currently
test.gwf fille:///home/duncan/test.gwf pool="sugar"
test.gwf fille:///home/duncan/test.gwf pool="caltech"