背景: 某表忽然出现查询很缓慢的情况.cost 100+ 秒以上:严重影响生产. 原SQL: explain plan for select * from ( select ID id,RET_NO retNo, FROM_SYS fromSy, TO_SYS toSys, COMMAND_CODE commandCode, COMMAND, STATUS, EXT_CODE, ORIGN_CODE orignCode,error_message errorMessage, RE_F, RET_…