Java serialization?

a) it could be that an attribute requires a lot of storage space, but can be calculated relatively easily from the other, or that very many instances share the same value of an attribute (with a greater storage requirement).

(b) What were the key goals or the most important goal in the design of Java? Also search for "Java platform-specific objects" (here the word "object" could also be a write error).

c) Of course, confidential information must be suitably encrypted, but it has nothing to do with whether to be included in data storage. (That it may be useful to serialize with the instance only a reference to separate data storage is a completely different question.)

d) If a printing company should create personalized New Year greeting cards for all customers, what data do they need (and which might not)? (Where, for example, the information on which sales have been made with a customer is covered by data protection and business secret, see point (b))