I read a lot about cascading deletes, which I interpret as holding personally identifiable data redundantly. I can see two reasons why this would be a problem:

I read a lot about cascading deletes, which I interpret as holding personally identifiable data redundantly. I can see two reasons why this would be a problem: You have a really shitty un-normalized database design. Granted that you may have to denormalize specific columns for performance reasons. But why that would be the case with, for example names, phone numbers or sexual preferences, totally escapes me. Or, you're referring to actual cascading deletes, meaning that you need to get rid of child relations, based on deletion of the parent relation. If this poses a problem then I'd argue that you're guilty of a shitty database implementation, arguably with criminally bad definition of your primary / foreign key pairs. I really don't see a problem here, unless the database schema is implemented in a totally incompetent manner. Edit: Clarity