"DDL is a nightmare"
Can I ask more about this? I assume you created a procedure around making DDL changes to the global cluster... what was that procedure like? what tools did you use (create) to automate/script this? what failure modes did it encounter?
Bold of you to assume it was automated. The process I used was tmux with pane synchronization.
I asked to automate it (probably would've just been a shell script, _maybe_ Python, issuing SQL commands to stdin), but people were afraid of unknown unknowns.