foreign key referencing inheritance parent

This has come up before elsewhere e.g.

https://stackoverflow.com/questions/26034752/postgresql-inheritance-and-foreign-key-referencing-parent-table

but I don't see any mention in any pg mailing list.


postgresql permits creation of a foreign key referencing a table which 
is the parent of child tables via inheritance

but enforces that every foreign key value must exist as pkey ONLY in the 
parent  -  it throws an ERROR otherwise, even if the pkey exists in a 
child table.

This is problematic (to me) for three slightly different reasons :

1)   it is surprising.    The expectation is that a reference to 
accessing row(s) in a parent table will also search all children,   as 
with SELECT,  unless the ONLY keyword is specified.

which then leads to ...


2)    it is inconsistent with,  and less useful than,    the somewhat 
similar CHECK clause in a CREATE/ALTER TABLE :

_____________________________________________________

          CHECK ( expression ) [ NO INHERIT ]

A constraint marked with NO INHERIT will not propagate to child tables.

_____________________________________________________

For CHECK,   the default is propagation to child tables unless 
explicitly prevented,  which is consistent with SELECT and the ONLY 
qualifier.

For FOREIGN KEY there is no optional qualifier to express "propagation"  
(i.e. propagation of the search for primary key) or "ONLY" and the 
behaviour is always "ONLY".


3)   I am probably wrong but as far as I can tell this behaviour is not 
documented anywhere.


Would there be any interest in providing a choice,   e.g. an optional  [ 
INHERIT ] on the REFERENCES clause,  in a future release?


Cheers,  John