Adding specific information to a local file I have several files on a webserver (not stored in the database). I'd like to store several information to this specific file. The user should be able to post comments about this file. 

My question is:

What is the best way in order to store information in a database in addition to a file that is stored on a webserver... How do I connect both parts?
For a SQL Server solution, FILESTREAM (or FILETABLE if you can use SQL Server 2012) was built to solve this type of problem.

This solution will allow you to store the files in a central network location (most importantly, not on a web server box) outside the database, and manipulate metadata information within the database.

As mentioned in my comment, other RDBMS systems may also have similar capabilities (I'm not familiar enough with them to say, though).