This may seem like a silly question, but what do you actually want to use a RDBMS for ?
If you just want to store files, then the operating system's filesystem is generally adequate. An RDBMS is generally used for structured data and (except for embedded ones like SQLite) handling concurrent manipulation of that data (locking etc). Other useful features are security (handling access to the data) and backup/recovery. In the latter, the primary advantage over a regular filesystem backup is being able to recover to a point in time between backups by applying some form of log files.
BLOBs are, as far as the database concerned, unstructured and opaque. Oracle does have some specific ORDSYS types for multi-media objects (eg images) that also have a bunch of metadata attached, and have associated methods (eg rescaling or recolouring an image).