Surrogate keys

In data warehouse tables, surrogate keys are meaningless generated values that uniquely identify the rows in a table. Surrogate keys usually serve as the table's primary key values.

Surrogate keys are useful for two different reasons:
  • Because they are meaningless values, they are durable. All of the meaningful attributes of a row can change without affecting the integrity of the row as a unique record.
  • Because they are compact numeric values, they are very efficient for both table loads and query processing.