Hi again.
After some check back with development I can only stress what I mentioned in Alter Table Error
The current implementation of constraints and especially the referential constraints was done to suit a quite narrow and specific set of requirements.
Like any other DBMS it doesn't provide a general functionality - sadly unlike most other DBMS the available functionality is not yet applicable for a broad range of applications.
As I mentioned before elsewhere here in SCN SAP HANA development does have this on their radar.
And surely enough, big paying customers are setting the priorities and ref. constraints like other core database features are very often not on the very top of the wishlist.
- Lars