select *from v_zcdd_kh where 1=1 and (pc_ssbm='1002') and gzs=0 and d_bdrq>='2008-5-1' and d_id in (select d_id from v_zcxx where 1=1 and (pc_ssbm='1002') and gzs=0 and d_bdrq>='2008-5-1')select *from v_zcdd_kh where 1=1 and (pc_ssbm='1002') and gzs=0 and d_bdrq>='2008-5-1' and exists (select 1 from v_zcxx where v_zcxx.d_id=v_zcdd_kh.d_id and v_zcxx.pc_id=v_zcdd_kh.pc_id and (pc_ssbm='1002') and gzs=0 and d_bdrq>='2008-5-1')想问一下,这两句的执行速度如何,我以前是用上面这个的,但想试一下exists,不知道这样写对不对?
--先执行
SET SHOWPLAN_ALL ON--然后再执行你的语句