Glossary · Database

Column Descriptions

Column descriptions are human-readable annotations attached to database columns that explain what each column contains and how its values should be interpreted.

Column names compress meaning until it disappears: "amt_n" could be net amount, normalized amount, or amount in naira. Column descriptions restore the meaning–a sentence per column saying what it holds, its units, and its gotchas ("in cents, not dollars; null means pending"). Most databases support storing these as column comments, yet most teams never fill them in. The cost of that gap has gone up in the AI era: column descriptions are among the highest-value context you can give an AI query system, often turning ambiguous questions into correct SQL. Ten minutes documenting your twenty most-queried columns pays back immediately.

Fig — every answer ships with the tables, rows and SQL behind it.