Schedule - PGConf.DE 2023
LFMF: how a CREATE INDEX CONCURRENTLY led to a 6 hour downtime
Room: Room 2
War story time!
My client - who prefers to remain unnamed - introduced a new table with an ON DELETE CASCADE foreign key. Which wasn't backed by an appropriate index. Creating that missing index (and a couple of bad decisions, some of them many years in the past) led to a downtime of about six (!) hours.
describes* what happened
then explains what happened and
shows which decisions - by the client, the DBA (me), but also the PostgreSQL developers TBH - caused the catastrophic course of events
Obviously, we'll also discuss the lessons learned and which measures were taken to prevent a reoccurence.
This completely took me by surprise (and what an unpleasant one!), so:
Learn from my fail!