计算日志大小：

 select * from v$sesstat where statistic#= (select statistic# from v$statname where name ='redo size') and sid = (select distinct sid from v$mystat);

隐含参数修改：

SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ
FROM SYS.x$ksppi x, SYS.x$ksppcv y
WHERE x.inst_id = USERENV ('Instance')
AND y.inst_id = USERENV ('Instance')
AND x.indx = y.indx
AND x.ksppinm LIKE '%&par%';