This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
I think the *.db file acts as the database in which all records have been stored, thus all your operation including reading,updating and finding records etc. must associate with this file directly or indirectly,depending on whether you use the cache technology.