Over time, the properties associated with an entity—both static and changing, singular or composite—will form a concrescence (Whitehead 1929), or, in other words, its identity
object’s identity is a complex question, and is defined in concrete domain with it’s concrete restrictions. There could be situations when only one attribute identifies object, and when union of all attributes don’t identify object. Also, object identity could be different in different scopes (object can live in database, in computer’s memory, be distributed in cluster). Technologies can dictate object’s identity as well (for instance, surrogate primary keys in database). Therefore this statement in the book is not totally correct.
Share this highlighthttp://www.safaribooksonline.com/a/the-joy-of/2710714/