gistfile1.txt

select
  pg_namespace_parent.nspname as parent_schema, pg_class_parent.relname as parent_table, pg_attribute_parent.attname as parent_column,
  pg_namespace_child.nspname as child_schema, pg_class_child.relname as child_table, pg_attribute_child.attname as child_column
from
(
  select
      pg_constraint.conrelid        as "parent_table_id",
      unnest(pg_constraint.conkey)  as "parent_column_id",
      pg_constraint.confrelid       as "child_table_id",
      unnest(pg_constraint.confkey) as "child_column_id"
  from
      pg_class
      join pg_namespace  on pg_class.relnamespace = pg_namespace.oid
      join pg_constraint on pg_class.oid          = pg_constraint.conrelid
  where
      (pg_namespace.nspname, pg_class.relname) in (('SCHEMA_NAME', 'TABLE_NAME_1'), ('SCHEMA_NAME', 'TABLE_NAME_2'))
      and pg_constraint.contype = 'f'
) info
join pg_attribute as pg_attribute_parent on pg_attribute_parent.attrelid = info.parent_table_id and pg_attribute_parent.attnum = info.parent_column_id
join pg_attribute as pg_attribute_child  on pg_attribute_child.attrelid  = info.child_table_id  and  pg_attribute_child.attnum = info.child_column_id
join pg_class     as pg_class_parent     on pg_class_parent.oid = info.parent_table_id
join pg_class     as pg_class_child      on pg_class_child.oid  = info.child_table_id
join pg_namespace as pg_namespace_parent on pg_namespace_parent.oid = pg_class_parent.relnamespace
join pg_namespace as pg_namespace_child on pg_namespace_child.oid = pg_class_child.relnamespace;