Surrogate Keys and Performance
When you use a short surrogate or internal key to replace a bad key, or because there is no good key, consider the performance trade-offs. The set processing of data includes the overhead of deriving the key.
Surrogate key types include:
• Natural
Universal (a social security number or zip code are examples)
• Environmental
These are local to an organization, like an employee number.
• Design artificial. These are:
– Local to an application
– Hard to remember
– Hard for users to understand
– Can be hidden from users