得到所有隐藏的参数我们使用下面一个SQL 查询语句：

select *

from SYS.X$KSPPI

where substr(KSPPINM,1,1) = '_';

下面SQL 语句结果显示是哪些当前值的隐藏变量：

select a.ksppinm "Parameter", b.ksppstvl "Session Value", c.ksppstvl "Instance Value"

from x$ksppi a, x$ksppcv b, x$ksppsv c

where a.indx = b.indx and a.indx = c.indx

and substr(ksppinm,1,1)='_'

order by a.ksppinm;