Step 3 of 7
Databases: SQL vs. NoSQL, schemas and normalization
Relational (SQL) databases like Postgres store data in tables with relationships and strict types. NoSQL stores (document, key-value) trade some of that structure for flexibility. Normalization means storing each fact once and linking to it, instead of copying it everywhere.
Why it matters when you build with AI: Most apps should start on Postgres. A well-designed schema prevents an entire class of bugs before any code runs.
Quick check
Normalization means…
One fact, one place. Fewer inconsistent copies, fewer bugs.