子查询展开

select  nsrsbh from v_sb_sbxc where djxh in (select djxh from v_sb_yzstj=:1);

v_sb_sbxc, v_sb_yzstj 2个视图  用的是2个表union all

子查询展开

select  nsrsbh from v_sb_sbxc a,(select djxh from v_sb_yzstj=:1) b  where a.djxh=b.djxh

逻辑读从200万降低到20，在用sqlprofie绑定执行计划。