#Query Optimization

A practical Postgres performance guide: read query plans with EXPLAIN, index the right columns, kill N+1 queries, and pool connections so the database scales.

What the N+1 query problem is, why ORMs cause it by default, how to spot it, and the patterns that eliminate it for good.

How Postgres index-only scans avoid touching the table heap, when they kick in, and how the visibility map quietly decides everything.