利用rowid删除数据，提升性能

DELETE FROM i_br_all_user_real t
WHERE EXISTS (SELECT 1
FROM i_br_card_return a
WHERE t.imsi_no = a.imsi_no
AND t.oper_date <= to_date(a.return_date,
'YYYYMMDDHH24MISS'));
--用rowid删除数据

DELETE FROM i_br_all_user_real
WHERE ROWID IN (SELECT a.rowid
FROM i_br_all_user_real a,
i_br_card_return b
WHERE a.imsi_no = b.imsi_no
AND a.oper_date <= to_date(b.return_date,
'YYYYMMDDHH24MISS'))