Subject System Tables Question
Author Alan McDonald
I notice that SYSTEM TABLES generally don't have PKs, nor unique
constraints, merely unique indices.
Is there a reason for this?
Is it a case of "do as I say not as I do" or is there history in this? e.g.
the concept PKs didn't exist when the engine started dev.
Or is performance better without these constraints and the engine "protects
itself" in their absence?