How to find hidden session parameters in ORACLE?

Question

Oracle

Hi all!
Tell me how to find out the hidden session parameters in ORACLE?
Namely "_complex_view_merging", "_replace_virtual_columns".
I searched the internet but couldn't find how to do it.

Answer 1

Если есть доступ под sys, то, например, вот так:
select a.ksppinm name,
b.ksppstvl value,
b.ksppstdf deflt,
decode
(a.ksppity, 1,
‘boolean’, 2,
‘string’, 3,
‘number’, 4,
‘file’, a.ksppity) type,
a.ksppdesc description
from
sys.x$ksppi a,
sys.x$ksppcv b
where
a.indx = b.indx
and
a.ksppinm like ‘\_%’ escape ‘\’
order by
name

If there is no access under sys, then you can say, for example:
You will see the value of this parameter if it is not default.
You will also see the values ​​of these parameters, if they are not default, at the end of the AWR report.
You can, to the heap, make 10053 trace - they will be there in any case.
Default values ​​for version 11g for both parameters: true.