They could help if the tags were 'Occupation = Plumber' and 'Name = Joe'. Now a search for all files where both tags are present will get you Joe the Plumber's invoices. If you want everything from any plumber or from any person named Joe, then just leave off one of the tags from your search. It is very much like when querying rows in a relational database, just adjust your WHERE clause.
I agree. Unfortunately, right now the 'well structured relational database' is completely separate from the file system. Didgets was designed to combine the two into a single coherent system so that you can't update one without the other. By 'combining' doesn't mean I did what WinFS tried to do and just take a filesystem and a database and stick them together somehow. I built a completely new system from the ground up that incorporates traditional filesystem features (block allocation, stream management, metadata control, folder hierarchies, etc.) with solid relational database features (schema, tags).
