Introduction
In the world of databases, keys play a vital role in linking and identifying data across tables. One such key is a Surrogate Key, a concept often used in SQL databases.
In this article, we'll delve into what Surrogate Keys are, why they're used, and how to create them in SQL.
What is a Surrogate Key?
A Surrogate Key is a unique, system-generated identifier used as the primary key in a table. It's not derived from the data in the table and usually has no meaningful business value. Surrogate keys are often integers, but they can also be other data types, such as sequential unique identifiers (UUIDs).
Why Use a Surrogate Key?
The main reasons to use Surrogate Keys are simplicity, performance, and stability. They're simple because they're often just incrementing integers, meaning they're easy to manage and understand. They offer good performance, especially in large databases, because comparing integers is usually faster than comparing other data types. Finally, they provide stability because they don't change, even if other data in the row changes.