SQL查询，而我正在执行选择查询其加载很长一段时间，而不是导致其唯一的加载

不导致加载

select p.*
from contacts p left outer join
     (select articleno, size, count(*) as cnt
      from bsd t
      group by articleno, size
     ) bc
     on p.articleno = bc.articleno and p.size = bc.size
where coalesce(cnt, 0) < (select count(*)
                          from contacts p2
                          where p2.articleno = p.articleno and
                                p2.size = p.size and
                                p2.id <= p.id
                         );