i would be doing some operation with my DB. now mine is a JEE application and am using JPA. when i am dealing with my DB (or data), its quite possible that some other legacy application might also be manipulating the same data, since there are quite a few appliations accessing the same DB. Now i do not want the other application to access my data when i am dealing with it. How could i achieve this exclusive access so that no other application can possible corrupt my data.