Vol. I · A Postgres Handbook

The Query & the Schema

A reading-room reference for writing PostgreSQL by hand — selects to window functions, with the schema in plain view.

AdvancedAdvanced PostgreSQL

EXPLAIN ANALYZE: understand query execution

The query

SQL
EXPLAIN (ANALYZE, BUFFERS, FORMAT TEXT)
SELECT
  e.first_name,
  e.last_name,
  d.dept_name
FROM employees e
JOIN departments d ON e.dept_id = d.dept_id
WHERE e.salary > 80000;
Tested against PostgreSQL 16

Note

“EXPLAIN ANALYZE runs the query and shows actual vs estimated row counts. BUFFERS shows cache hits. Key metrics: cost, rows, loops.

Tables referenced