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Learn PostgreSQL — Beginner to Advanced

PostgreSQL is the world's most advanced open-source relational database — and arguably the most beloved one. This free hands-on tutorial covers the SQL you'll write every day plus the Postgres super-powers: JSONB, arrays, CTEs, LATERAL joins, GIN/GiST indexes, and more.

The track is organised by topic, with concise explanations, real psql examples, and practice exercises. Use the sidebar to jump straight to the feature you need, or follow the curriculum in order from Introduction to PostgreSQL through to advanced performance topics.

PostgreSQL skills transfer everywhere: it is the default database of modern web development, the engine behind many cloud services, and the foundation for extensions like PostGIS and TimescaleDB. This track is written for developers and analysts who want practical, runnable answers — every topic pairs syntax with a realistic example and exercises you can adapt to your own schema.

What you'll learn in this PostgreSQL tutorial

  • psql, connections, and the PostgreSQL CLI workflow
  • Data types including arrays, JSONB, hstore, and ranges
  • Joins, CTEs, window functions, and LATERAL queries
  • INSERT, UPDATE, DELETE, UPSERT with ON CONFLICT
  • Schemas, sequences, and B-tree / GIN / GiST indexes
  • Transactions, isolation levels, and EXPLAIN ANALYZE

Common use cases for PostgreSQL

Web and SaaS application backends

PostgreSQL is the default choice for new web applications — free, open-source, ACID-compliant and supported by every major framework and cloud provider (RDS, Cloud SQL, Azure Database, Supabase, Neon).

Hybrid relational + document workloads

JSONB columns with GIN indexes let you store and query semi-structured documents next to relational data — often removing the need for a separate NoSQL database.

Analytics, geospatial and time-series data

Window functions, CTEs and LATERAL joins handle serious analytical SQL, while extensions like PostGIS (geospatial) and TimescaleDB (time-series) extend Postgres into specialised domains.

Frequently asked questions about PostgreSQL

Is PostgreSQL really free to use?
Yes — PostgreSQL is open-source under the permissive PostgreSQL License, free for any use including commercial products. There are no paid editions or feature gates; managed cloud hosting is the only thing you might pay for.
Should I learn PostgreSQL or MySQL first?
Either teaches you transferable SQL, but PostgreSQL is the stronger long-term bet: richer SQL support (full window functions, CTEs, LATERAL), better standards compliance, JSONB, and it tops developer-survey popularity rankings year after year.
Do I need to install PostgreSQL to follow this tutorial?
No. The concepts and most queries can be practised in SQLMentor's free in-browser editor. For Postgres-specific features like JSONB operators, the tutorial shows exact psql commands you can run later in a local install or a free cloud instance.
Is there a PostgreSQL certification?
Yes — the PostgreSQL Associate certification validates fundamentals like MVCC, indexing, replication and configuration. SQLMentor offers a free 30-question timed practice exam for it, linked from this track.
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