Hello community,
how do you go about finding information about constraint columns? I
was trying to use the view information_schema.constraint_column_usage
but I've found out that to uniquely identify a constraint it would
need to show the constraint table, but in case of foreign keys it only
shows the table of the referenced column.
For example:

create schema proves;

create table proves.test (suc_pk int primary key);

create table proves.test1 (suc_fk integer);

create table proves.test2 (suc_fk integer);

alter table proves.test1 add constraint fk1 foreign key (suc_fk)
references proves.test;

alter table proves.test2 add constraint fk1 foreign key (suc_fk)
references proves.test;

then when I try to read the constraint the columns reference I can't
know distinguish the constraint on test1 from the constraint on test2:

select * from information_schema.constraint_column_usage
where constraint_name = 'fk1';

I guess I could look at the view definition and add use the same query
but adding the table constraint, but I don't know if these view
definitions might change with new postgres versions or not, I would
like something that I don't have to worry that it might stop working
in the future.
How would you go about it?


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