attrelid, 'conincluding', atttypid, attstattarget, attlen, 25, attndims, attcacheoff, atttypmod, attbyval, attstorage, attalign, attnotnull, atthasdef, attisdropped, attislocal, attinhcount, attcollation, attacl, attoptions, attfdwoptions

from pg_attribute

where attrelid = 'pg_constraint'::regclass::oid and attname ='conkey';