Master data and key field?

Hi,

We are using 0equipno master data.There is standard data source for this 0equipno and we are using this for the same.But this 0equipno is having an attribute 0equiptype.But with the some other requirements we were asked to add some navigational attributes to 0equiptype.0Equitype is using a view called T370K.But now my qestion is when I load data to a 0equiptype then all the previous data which ara available by loading 0equipno is also present.But as per the logic old data has to be overwritten right?