Interview Q&A / PostgreSQL

INTERVIEW Q&A · 69 QUESTIONS

PostgreSQL interview questions

Indexes, EXPLAIN, transactions and isolation, JSONB and the Postgres specifics backend interviews probe.

  1. How do you find which query is blocking another in PostgreSQL?

    Look at pg_stat_activity for sessions with wait_event_type Lock, and use pg_blocking_pids(pid) to get the PIDs holding the lock. Then inspect those sessions and, if needed, cancel or terminate the blocker.

    IntermediateQuick answer1 min read