select l.shipid, l.shiplockid, l.upordown, s.shipspeed from LockCheckin l, ship s where l.LockCheckinid not in (select LockCheckinid from SCHEDULEEXECS) and l.shipid=s.shipid(+) order by shiplockid
这是小弟写的sql，其中LockCheckin 和 SCHEDULEEXECS 都是百万级，偶尔会达到千万级的表，小弟知道not in的效率非常之差，详情大神们看看如何能提高数据查询效率
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- SQL code
--LockCheckin中的shipid,LockCheckinid建立聯合索引--ship中的shipid建立索引--SCHEDULEEXECS中的LockCheckinid建立索引--這些只是為了測試速度，測完後再恢復為你之前的select l.shipid, l.shiplockid, l.upordown, s.shipspeed from LockCheckin l, ship s where l.shipid=s.shipid(+) and not exists (select 1 from SCHEDULEEXECS where SCHEDULEEXECS.LockCheckinid=l.LockCheckinid)order by shiplockid