I am planning to design a database with 8 tables with some columns to store the register information(Current Version is A). Also in future i am going to modify the register information (modified version of the register is version B) and store the data related to version B. Currently i am planning to query data related to version A but in future i am planning to query data related to version A as well as B from the database. Can anyone please help me to design the database with the revision control.? How can i get the information from database related to Revision A or revision B?