Re: BUG #16045: vacuum_db crash and illegal memory alloc after pg_upgrade from PG11 to PG12

Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> Well, I think I found the root cause. It's because of 7c15cef86d, which
> changed the definition of sql_identifier so that it's a domain over name
> instead of varchar.

Ah...

> Not sure what to do about this :-(

Fortunately, there should be close to zero people with user tables
depending on sql_identifier.  I think we should just add a test in
pg_upgrade that refuses to upgrade if there are any such columns.
It won't be the first such restriction.

            regards, tom lane