Redgate Simple Talk

The Secret Life of Database Keys

The article demystifies database keys, contrasting natural keys—business‑meaning values—with surrogate keys that are system‑generated identifiers. It outlines why surrogates are favored for stability, compactness, and predictable performance, while also noting scenarios where natural keys or composite junction keys are preferable. The piece evaluates non‑sequential alternatives such as UUIDs and ULIDs, highlighting their uniqueness benefits and storage costs. Finally, it advises sizing primary keys for future growth and limiting key exposure to preserve security and flexibility.