SQL joins: a small reference with predictable results
Use a tiny customer-and-order dataset to see inner joins, left joins, and the filter placement that changes their meaning.
PostgreSQL.
A relational database for transactional applications, rich SQL, and extensible data types.
Official documentationWhere it fits
A relational database for transactional applications, rich SQL, and extensible data types.
This profile covers a database in the Relational databases category.
Evaluate it for your workload
Start with your access patterns, data size, concurrency, and recovery requirements. Check the official documentation for the exact edition, engine version, and deployment model you intend to use.
For self-managed deployments, account for upgrades, monitoring, access controls, and the process for recovering your data.
Learn by doing
Related guides appear below as they complete editorial review. Use those examples as a starting point for testing a representative development workload.
Put it into practice.
Guides & tutorialsA transaction is a boundary, not a magic shield
Separate atomicity from isolation and learn why two individually correct transactions can still surprise each other.
Window functions: keep the rows, add the context
Calculate a running total and rank orders within each customer without collapsing the underlying rows.
Read a PostgreSQL query plan without getting lost
Follow the work through a query plan, compare estimates with actual rows, and learn what to investigate before adding another index.