Why this chapter matters
Fast, stable queries keep dashboards responsive and reduce infrastructure cost under growth.
What you will learn
- Read basic EXPLAIN output to spot expensive operations.
- Use indexes that match common filter and join predicates.
- Avoid anti-patterns that defeat index usage.
Lessons in this chapter
- Plan-first optimizationInspect PostgreSQL execution plans before changing query structure. Read the full guide →
- Index strategy fundamentalsMap frequent predicates to practical index definitions.
- Sargable filter patternsWrite predicates that allow index scans when possible.
- Safe performance testingBenchmark with representative data and verify result equivalence.
Study task
Take a slow PostgreSQL dashboard query, run EXPLAIN, add one targeted index, and compare plan and runtime before and after.
Chapter checkpoint
What PostgreSQL command helps you inspect how a query will execute?
EXPLAIN shows the planned execution strategy, and EXPLAIN ANALYZE also runs the query with timing.