Databases
SQL Database
A relational database that stores data in structured tables with enforced schemas and is queried with SQL, like PostgreSQL or MySQL.
A SQL database stores data in tables with defined columns and relationships, and enforces a schema so the shape of your data stays consistent. You query it with SQL, and it guarantees transactions: a set of changes either all succeed or all roll back. PostgreSQL and MySQL are the two that run most of the web, with MariaDB as a drop-in MySQL fork.
The strengths are consistency and expressive queries. When your data has relationships, orders belong to customers, invoices to accounts, a relational database models that cleanly and answers complex questions in one query. This is the right default for most applications, which is why nearly every managed database offering starts here.
Scaling writes across many machines is the historical weak spot, and it's why NoSQL exists. But for the vast majority of projects, a single well-provisioned Postgres instance with a read replica handles far more than people expect. Reach for something exotic only after you've measured a real limit.
Go deeper
- Managed Database vs Running Your Own: The Real MathA managed PostgreSQL costs 2-4x the raw server underneath. Whether that premium is worth it depends on exactly one question: what your untested backup is worth.