Kouber Saparev <kouber(at)gmail(dot)com> writes:
> I noticed that attaching the "_RETURN" rule to a table converts it to a
> view, and the operation is irreversible, i.e. once attached, I cannot drop
> the rule and put the relation back to a table one.
That is an ancient backwards-compatibility hack that you should not
rely on, and most certainly shouldn't try to make use of from user
code. It exists because very ancient versions of pg_dump didn't
know how to dump views as views. We're more likely to rip it out
as no-longer-needed than to expand what it does.
regards, tom lane