Transaction ID wraparound and avoiding the performance penalties from autovacuum tuple freezing

Transaction wraparound is a known issue in Postgres, and any experienced Consultant has at least once had to deal with server performing an emergency shutdown to prevent corruption due to transaction ID wraparound. That is a safeguard, just like autovacuum running “vacuum to prevent wraparound”. But the safeguards come with a price to pay. We’ll talk about all this, and how to avoid as much as possible this special autovacuums and especially the emergency shutdown. -- Martín Marqués - Deputy head of support at 2ndQuadrant, with over 20 years of experience in Open Source and more than 18 years working with Postgres.