[rules-users] Guvnor seems to copy assets across External RDBMS and file system

I set up SQL Server as the external repository, and left everything else in guvnor and jboss AS7 configured pretty much according to defaults. When I create assets in guvnor, I see that changes are being made in the MSSQL db. Despite changes to the db, however, I'm still seeing changes to the Repository and Workspace folders. It gets more interesting when I truncate the tables in the external guvnor db, and restart guvnor, it seems to get all of its assets back from those two folders. Am I doing something wrong? Is it reconstructing the assets from lucene indexes? If MSSQL is already indexing things, is the lucene index still necessary? Are these basic JCR concepts that I am not grasping? Thanks, Yuri