PostgreSQL for Beginners

Every PostgreSQL explainer for beginners: 1 video, each with its commands, real output and diagrams.

Videos

10 minOct 22, 2026

Why PostgreSQL Ignores Your Index

You added an index, but EXPLAIN ANALYZE still says Seq Scan. This beginner-friendly guide explains what an index really is, how the PostgreSQL planner decides whether to use it, and the six real reasons it skips your index, each proven on a real PostgreSQL 18.6 database with a one-million-row table, with the fix for each.