Duilio,

looks like you forget the real master-detail relationship.
What you want to do can perfectly be done with foreign keys, if you add
a STAR table above your SYSTEM table, like:

STAR_ID STAR_NAME
1 SUN
2 BETEIGEUZE

and then add your SYSTEM like:

STAR_ID PLANET_ID
1 1000
1 1001
1 1002

and so on....

Then you can easily drop the sun and (by cascading) all it's planets if
you're going to decide to build a hypergalactic bypass. ;-)


Luc.