consider using sqlite made for being an allmost universal fileformat also allowing transactions. Its fully ACID (Atomicity, Consistency, Isolation, Durability)

consider using sqlite made for being an allmost universal fileformat also allowing transactions. Its fully ACID (Atomicity, Consistency, Isolation, Durability) and even allows concurrent access (serializes writes) it's probably the most deployed "database" (thousends of embedded devices, it's the fs one some ;-) .