Description:
It'd be nice to be able to match a running alter on an existing table to the intermediary it's using.
considerations:
- there can be many alters running at the same time on a server, so you can't just check processlist
- identifying it by matching columns, indexes, etc (like in the innodb_sys_* tables) isn't practical as the alter could be adding/removing as many of those as it wants
How to repeat:
alter some tables and start guessing
Suggested fix:
some way to link it. it's easy to find the thread doing the alter (from perf schema, processlist, innodb_trx, anywhere), and it's easy to identify the intermediary (perf schema file info, innodb_sys tables), but there's no way to connect the two.