PostgreSQL as a filesystem

This isn’t a high-priority question.

I’m developing a hobby OS and I’m looking into file systems.  I’ve thought about writing my own, and that appeals, but I’m also very interested in the database-as-a-filesystem paradigm.  It would be nice to not have to write all of the stuff that goes into the DBMS (e.g. parsers, query schedulers, etc) myself.  

So I was wondering what sort of filesystem requirements Postgre has.  For example, could I write a simple interface layer that just requests blocks from the physical device and translate those into byte sets, or does the DB actually require multiple files mapped by a larger file system that maintains names, etc.

I guess my real question is how much file system support is really required by the DBMS’s disk routines.  Please reply to nadiasvertex@gmail.com since I’m not subscribed to this list.  Thanks in advance!

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