Generation Numbers (Access/SQL cont’d)
Each replica has a current generation number
A replica updates a row’s generation number whenever it updates the row
A replica knows the generation number it had when it last exchanged updates with R´, for every replica R´.
A replica increments its generation number every time it exchanges updates with another replica.
So, when exchanging updates with R?, it should send all rows with a generation number larger than what it had when last exchanging updates with R?.