I can imagine a hybrid file system where a hierarchical structure is used for several levels, before bottoming out in a directory of databases. Ideally this wou

I can imagine a hybrid file system where a hierarchical structure is used for several levels, before bottoming out in a directory of databases. Ideally this would be accessible/searchable by DB index from all levels of the directory hierarchy. I'm sure something like this has been implemented of which I am ignorant.