Re: multi column foreign key for implicitly unique columns - Mailing list pgsql-sql

Jan,

> Because the value in b.y is redundant. b.x->a.x->a.y is exactly the same
>   value and he even wants to ensure this with the constraint.

And in the absence of that constraint, what ensures that b.y = a.y, exactly?

-- 
Josh Berkus
Aglio Database Solutions
San Francisco