SQL vs NoSQL

The useful question is not which database is better.

The useful question is which database model fits the workload.

Relational Databases

Relational databases provide:

• tables,
• relationships,
• constraints,
• transactions,
• joins,
• powerful querying.

CREATE TABLE orders (
  id uuid PRIMARY KEY,
  user_id uuid NOT NULL REFERENCES users(id),
  total_cents integer NOT NULL CHECK (total_cents >= 0)
);

NoSQL Is Not One Thing

NoSQL can refer to:

• document databases,
• key-value stores,
• wide-column databases,
• graph databases.

Start With Access Patterns

For many applications, PostgreSQL is an excellent starting point.