First of all, reposting the same question every three minutes is a waste of
your time and public bandwidth. You normally need to wait at least several
hours to get a response to a question so be patient and give people a chance
to see your question and write a reply.

Second, I have no idea what a 'funda' is. This is not an English word that
I've ever heard before and I've been speaking English for 50 years. You will
need to clarify your question before it can be understood properly.

Your questions also talk about database and persistence; I am quite familiar
with database but I haven't worked with persistence layers yet, although I
plan to start soon. It is my understanding, and I could be wrong, that there
are several different programs/products that let you build persistence
layers. I would expect that each one works somewhat differently and has
somewhat different principles and procedures. Again, I could be wrong:
perhaps there is a universally agreed set of principles followed by all
persistence layers. But if I'm right, perhaps it would be best for you to
choose a particular persistence layer product first, then ask for help at
the support organization for that product.

For example, I have the impression that Hibernate is one of the most popular
persistence layer products. I know that you can find it at
http://hibernate.org. You can access the Hibernate forums and mailing lists
there. You will probably find more persistence experts there than in the
comp.lang.java.* newsgroups and therefore more people who can answer your
question.

With regards to serialization, Roedy Green has a lengthy article about this
subject at http://mindprod.com/jgloss/serialization.html. The article
includes links to other articles on his site and at the Sun site. This might
be a good way to learn about serialization.

--
Rhino