I don't really know why you're getting downvoted. Plan9 is relevant to this space as it takes "everything is a file" to the logical conclusion in the same way that this takes "everything is a database" to the logical conclusion.
> The hierarchical organization of file systems manifests itself in nesting of directories (folders). On the other hand, directories are merely named views of a certain subset of files, selected according to some criteria. Thus, a directory can be thought of as a "database view," a named database query. It follows immediately that a file may appear in as many "directories" (views) as one wishes to. For example, one "folder" may show all files tagged as "sales reports", while another directory contains files modified within five days. Searching a file system and creating and populating a folder becomes therefore the same activity. Since saved views are database objects themselves, one can reference views within views if one so wishes. There is no required hierarchy however: one may create two views that refer to each other, or any other network of views that best suits the problem.
I built koios to solve this problem, but I didn't take the fuse approach because it seemed like a lot of extra work for the user, and puts databases first rather than files, which is un-UNIX.
