with ck as (select 
o.conname,
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table, 
c.oid as target_table_oid,
unnest(o.conkey) AS target_col,
substring(pg_get_constraintdef(o.oid),7) as consrc
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype = 'c' 
and cardinality(o.conkey)=2),
ck_names as (select ck.conname, ck.target_schema, ck.target_table, ck.consrc, string_agg(a_target.attname, ',' ORDER BY a_target.attname) as target_cols 
from ck inner join pg_attribute a_target on ck.target_col = a_target.attnum and ck.target_table_oid = a_target.attrelid and a_target.attisdropped = false
group by ck.conname, ck.target_schema, ck.target_table, ck.consrc)
SELECT target_cols, string_agg (target_schema || '.' || target_table || '.' || conname || '.(' || consrc || ')', ',<br>' ORDER BY target_schema, target_table, conname) AS tables
FROM ck_names
GROUP BY target_cols
HAVING Count(DISTINCT consrc)>1
ORDER BY target_cols;