What to use, CASCADE DELETE rule or ON DELETE trigger for one to many constraint?
I don't think you will see a performance difference between trigger and using cascade. I would prefer ON CASCADE DELETE just because in my opinion it better describes model and reveals creator's intention. Also, if you later use one or another ORM, it will be able to build relationship between entities (surely, I'm talking about 'Data First' approach)if it's implemented through foreign key constraints, but not through the triggers.