Re: Let's drop two obsolete features which are bear-traps for novices - Mailing list pgsql-hackers

In the case of hash indexes, because we still have to have the hash
opclasses in core, there's no way that it could be pushed out as an
extension module even if we otherwise had full support for AMs as
extensions.  So what I hear you proposing is "let's break this so
thoroughly that it *can't* be fixed".  I'm not on board with that.
I think the WARNING will do just fine to discourage novices who are
not familiar with the state of the hash AM.  In the meantime, we
could push forward with the idea of making hash indexes automatically
unlogged, so that recovering from a crash wouldn't be quite so messy/
dangerous.