SAP Sybase IQ provides protection against referential integrity loss.
Updates or deletes a primary key value that has a matching foreign key value. All the foreign keys referencing that primary key violate referential integrity.
Adds a new row to the foreign table, and enters a value for the foreign key that has no corresponding candidate key value. The database violates referential integrity.
When a referenced candidate key is updated or deleted, SAP Sybase IQ disallows UPDATE or DELETE.