relational-schema-design

name	relational-schema-design
description	Design a correct relational schema: normalize to 3NF, denormalize only with measured evidence and a named consistency cost, push constraints (PK/FK/UNIQUE/CHECK/NOT NULL) into the database, and choose precise data types.

Relational Schema Design

Normalize first

3NF by default: each fact once, relationships via keys. Most 'we must denormalize' instincts are premature.

Denormalize deliberately

Only with a measured read benefit AND the write/consistency cost named — often a materialized view or covering index is better than redundant columns.

Constraints in the DB

PK on every table, FK for every relationship, NOT NULL/UNIQUE/CHECK to make illegal states unrepresentable. The app is not a trustworthy enforcer.

Types

Precise numeric/temporal/text; uuid/enum/jsonb where they fit. text for everything + naive timestamps are smells.