I have a very little idea about what database file system is.
Can somebody out here explain to me what actually a database file system is, and what its applications are?
Typical file systems (*nix, ms-dos, etc) organize files hierarchically. For example,
c:\ represents the top of a hierarchy c:\foo is the next level in the hierarchy c:\foo\bar is a sub-node of \foo etc..
Each file exists in one and only one location in this hierarchy.
By contrast, a database file system organizes files by metadata attributes. For example, topic, type, author, etc.. Rather than existing in one particular place in a hierarchy, the file exists in multiple "places" depending on its attributes.
The last question you ask is unanswerable.
It's a file system that stores files as blobs in a database, rather than in a hierarchy of directories. Imagine a web-site with no "directory-like" hierarchy in the URL - just loads of tags and categories and a big "search" field - something like that, only on your hard-drive.
Pros & cons? Ask yourself, how many database filesystems have I ever seen? Do you need to ask more?
Found some good links
It's a file system where files have significant amounts of metadata. For example, the iTunes library might count as a database file system; not only do you have files on disk and know where they are, but you have tags (genres) and other metadata like author (artist).