Use generated (stored) columns for derived values

Use generated (stored) columns for derived values | BeforeMerge Rules | BeforeMerge

Why this matters

A value derived from other columns (a total, a normalized key) should be computed by the database, not re-implemented in every insert/update path where it can drift. GENERATED ALWAYS AS (...) STORED guarantees the value is always consistent with its inputs and can be indexed.

-- bad (app sets total on every write)
subtotal numeric, tax numeric, total numeric
 
-- good
total numeric GENERATED ALWAYS AS (subtotal + tax) STORED

Why This Matters

Related Rules

Catch this automatically on every PR

Why this matters