An entity has:
(i) a set of properties
(ii) a set of properties and values for all the properties
(iii) a set of properties and the values for some set of properties may non-uniquely identify an entity
(iv) a set of properties and the values for some set of properties may uniquely identify an entity
Which of the above are valid?
- (i) only
- (ii) only
- (iii) only
- (iv) only