Here is a query to see all the undocumented parameters
SELECT
a.ksppinm "Parameter",
decode(p.isses_modifiable,'FALSE',NULL,NULL,NULL,b.ksppstvl)
"Session",
c.ksppstvl "Instance",
decode(p.isses_modifiable,'FALSE','F','TRUE','T') "S",
decode(p.issys_modifiable,'FALSE','F','TRUE','T','IMMEDIATE','I','DEFERRED','D') "I",
decode(p.isdefault,'FALSE','F','TRUE','T') "D",
a.ksppdesc
"Description"
FROM x$ksppi a, x$ksppcv b,
x$ksppsv c, v$parameter p
WHERE a.indx = b.indx AND a.indx = c.indx
AND p.name(+) = a.ksppinm
AND UPPER(a.ksppinm) LIKE UPPER('\_%') escape '\'
ORDER BY
a.ksppinm;
