Checking Values of Hidden Parameters - Examples of how to use ESCAPE
Hidden parameters are parameters that normally start with an underscore (_%)
To find out all hidden parameters within an instance, login as / as sysdba and run the following sql
SELECT inst_id, parno_kspvld_values, name_kspvld_values , ordinal_kspvld_values, value_kspvld_values, isdefault_kspvld_values FROM x$kspvld_values
WHERE name_kspvld_values LIKE ‘\_%’ ESCAPE ‘\’
AND inst_id = USERENV (’Instance’);
The bonus, this will also give you an example of how to search a string with an underscore in it.