You can run the below query to find the value of the Hidden parameters set on the database
undef 1
set lines 150
column value for a40
col Parameter for a50
col "Default Value" for a13
col "Session Value" for a13
col "Instance Value" for a13
col IS_SESSION_MODIFIABLE for a25
col IS_SYSTEM_MODIFIABLE for a24
SELECT distinct a.ksppinm "Parameter", b.KSPPSTDF "Default Value",
b.ksppstvl "Session Value",
c.ksppstvl "Instance Value",
decode(bitand(a.ksppiflg/256,1),1,'TRUE','FALSE') IS_SESSION_MODIFIABLE,
decode(bitand(a.ksppiflg/65536,3),1,'IMMEDIATE',2,'DEFERRED',3,'IMMEDIATE','FALSE') IS_SYSTEM_MODIFIABLE
FROM x$ksppi a,
x$ksppcv b,
x$ksppsv c
WHERE a.indx = b.indx
AND a.indx = c.indx
AND a.ksppinm LIKE '_rollback_segment_%'
/
Parameter Default Value Session Value Instance Valu IS_SESSION_MODIFIABLE IS_SYSTEM_MODIFIABLE
-------------------------------------------------- ------------- ------------- ------------- ------------------------- ------------------------
_rollback_segment_count FALSE 4000 4000 FALSE IMMEDIATE
_rollback_segment_initial TRUE 1 1 FALSE FALSE
