[Zope] Object DB versus Relational DB

[Tom Deprez]

> A starting point is http://www.zope.org/Members/anthony/sql_vs_ZODB

Reading this text is exactly the problem I'm having. Unfortunately, it
doesn't give much examples.
I hope somebody can give me some answers on my question :

The problem I'm facing is the following. I've got a lot parent-child
relationships -> OODB
But, I also need to perform some queries on these records and link some to
each other -> more RDB.

I'm not sure which way to follow. A hybrid solution isn't the best one, I
think, because then you do twice the same work. ie. You've to create the
parent-child relationship in the OODB (the site structure) and in the RDB
(to perform correct queries).

The RDB solution is possible, but since I need lots of parent-child
relationships not the best one.

The OODB is probably the best. However, this implies several implementation
problems I don't know how to solve at the moment. Can somebody elaborate on
the following questions? Thanks in advance.

Assume the following :

Group1
   SubGroup1
      SubGroupA
          Problem1
              Examination1
                        Equipment1
                              Paremeters
                        Equipment2
                              Parameters
              Examination2

....

Campus1
   Room1
     Equipment1
     Equipment2
   Room2

....

Now,  if a person is creating a new equipment in Examination2. How can I
show it all the avalailable equipments in Campus1? So this person can choose
from it and create it in the examination2 folder? In an OODB environment?

If a person is browsing in Room1 and wants to get all the examinations which
will be performed on Equipment1. How do I create such a query in OODB? (Or
even further, the person wants to see all the examinations done on
equipment1, but only with Group=Group1 and SubGroup=SubGroup1

How can this be done in Zope?

Thanks in advance,

Tom.