Jonathan Tapicer <tapicer@gmail.com> writes:
> I was a able to do it using the pg_catalog tables, but I haven't found
> a way to do it using information_schema since it relies on foreign
> keys names being unique in the same catalog. Is this a known
> limitation?
Actually, the information_schema supposes that constraint names are
unique within a *schema*, not within a *catalog* (a/k/a database).
Don't know if that distinction can help you or not. You are correct
that Postgres is less rigid. We do not consider that to be a deficiency
on the Postgres side ;-)
If you want to use the information_schema to deal with this stuff, the
answer is to make sure that your application follows the SQL-standard
rule of not duplicating constraint names within a schema.
regards, tom lane