To identify the parameter one can query v$parameter view to find the parameters that were modified. The column ISMODIFIED is FALSE by default when the instance starts up, when the value is changed it is SYSTEM_MOD indicating the value is changed at the SYSTEM level and if it’s MODIFIED then it’s changed at session level.
-- Before parameter change displaying value of ISMODIFIED SQL> select name, value, ismodified from v$parameter where name = 'open_cursors'; NAME VALUE ISMODIFIED -------------------- ----- ---------- open_cursors 301 FALSE SQL> alter system set open_cursors=300; System altered. SQL> select name, value, ismodified from v$parameter where name = 'open_cursors'; NAME VALUE ISMODIFIED -------------------- ----- ---------- open_cursors 300 SYSTEM_MOD