{"UUID":"50a576ca-3171-417a-b001-50093be2d910","URL":"https://gocardless.com/blog/zero-downtime-postgres-migrations-the-hard-parts/","StartTime":"0001-01-01T00:00:00Z","EndTime":"0001-01-01T00:00:00Z","Categories":["postmortem"],"Company":"GoCardless","Product":"","Description":"All queries on a critical PostgreSQL table were blocked by the combination of an extremely fast database migration and a long-running read query, causing 15 seconds of downtime."}