Love this thing where Google Cloud decides that jepsen.io has been stable for a while and it really ought to do something about that, so it kills the VM and spins up a new one to replace it only *after* it's dead, resulting in ~10 minutes of spurious downtime.
It's been doing this for ~two years, COME ON Google, y'all are supposed to be experts at rollouts. Start new nodes *before* you kill existing ones!
So here's a neat thing postgres 12.3 might do? Maybe I'm doing it wrong, not sure yet.
All these transactions are executed with SERIALIZABLE isolation over lists implemented as comma-separated TEXT fields. `r x [1, 2]` means we read the current value of row x and found it to be [1,2]. `a x 3` means "append 3 to x", like so:
insert into txn1 as t (id, val) values ($1, $2) on conflict (id) do update set val = concat(t.val, ',', $3) where t.id = $4
rw is an anti-dep, ww and wr are deps.