Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> This requires a catversion bump, for which it may seem a bit late;
> however I think it's better to release pg11 without a useless catalog
> column only to remove it in pg12 ...
Catversion bumps during beta are routine. If we had put out rc1
I'd say it was too late, but we have not.
If we do do a bump for beta4, I'd be strongly tempted to address the
lack of a unique index for pg_constraint as well, cf
https://www.postgresql.org/message-id/10110.1535907645@sss.pgh.pa.us
regards, tom lane