> ComputeXidHorizons() already takes ProcArrayLock and has all the > information about who is blocking the vacuum, so I think we can > capture the blocker right there and get the reason almost for free, > without a second scan.
This idea proved to result in incorrect information. See [1] [1] https://www.postgresql.org/message-id/CAA5RZ0sjMgMo4Xg-niyyF-CpkQ_CK6uOfNKYT%3D9RmiBkAxQkbQ%40mail.gmail.com -- Sami Imseih Amazon Web Services (AWS)
