This is not specifically denormalization because I'm not combining/flattening two models - instead, I'm moving the special treatment for employees from a totall

This is not specifically denormalization because I'm not combining/flattening two models - instead, I'm moving the special treatment for employees from a totally separate path to a property of the existing customer model without removing/merging the employee model. Regarding read optimizations, there are several ways, some of which are vendor specific e.g. PostgreSQL/Oracle allow materialized views which can make accessing this data simple (if often required though they have their own issues).