Choose the narrowest correct column types

Choose the narrowest correct column types | BeforeMerge Rules | BeforeMerge

Why this matters

Wider-than-needed types waste disk, RAM, and index space, reducing how much data fits in the buffer pool and slowing every read. Size columns to the actual domain — e.g. INT UNSIGNED over BIGINT, VARCHAR(100) over VARCHAR(255) when 100 suffices.

-- Bad: oversized for the data
status_code BIGINT,
country_code VARCHAR(255)
 
-- Good: right-sized
status_code SMALLINT UNSIGNED,
country_code CHAR(2)

Why This Matters

Related Rules

Catch this automatically on every PR

Why this matters