Oracle 12c - Find if temporary objects created before TEMP_UNDO_ENABLED is set

Database : Oracle 12c (12.1.0.2) - Enterprise Edition with RAC

I'm trying to reduce REDO and archive logs generated for my application and measure using V$SYSSTAT and corresponding archive logs using DBA_HIST* views.

In my application code on DB side, I'm using the session level setting of TEMP_UNDO_ENABLED to direct UNDO for gtt into temporary tablespace. The specific feature noted here.

ALTER SESSION SET TEMP_UNDO_ENABLED = TRUE;
INSERT INTO my_gtt VALUES...

Note the documentation has this quote:

..if the session already has temporary objects using regular undo, setting this parameter will have no effect

If I use a pure database session, I can ascertain that since no other temporary tables have been created/used before setting the parameter, the REDO logs generated are minimal. I can use a simple (select value from V$SYSSTAT where name= 'redo size') to see the difference.

However the actual application (Java) triggers this code through a JDBC session. As such, I'm unable to ascertain if before the call to 'ALTER SESSION..' there were any GTT or other temporary objects previously created/used in the session. The consequence of this is, if say a GTT was already used, then the call to 'ALTER SESSION SET TEMP_UNDO_ENABLED = TRUE' simply ignores the setting without an indication. The code will continue logging UNDO & REDO in the normal tablespace, which is unintended.

Is there any way to query if this parameter TEMP_UNDO_ENABLED is already set/unset within the session, so that before I do a ALTER SESSION SET TEMP_UNDO_ENABLED = TRUE I'll know for sure this will or will not have an effect?

Thanks in advance for inputs.

Solution

There is no holistic way to do this satisfying all cases. Posting some options I got as answer elsewhere:

Assumptions : Both options work only if:

Only GTT is concerned (excluding WITH and other temporary objects)
COMMIT/ROLLBACK has not already been done including from SAVEPOINTS or other methods

Option 1 : Use v$tempseg_usage, to check if any segment created in DATA, instead of TEMP_UNDO

select count(*)
  from v$tempseg_usage
 where contents = 'TEMPORARY'
   and segtype = 'DATA'
   and session_addr =
       (select saddr
          from v$session
         where sid = sys_context('userenv', 'sid'));

Option 2 : Use gv$transaction as below, ubafil = 0 if for temp_undo, else ubafil = undo tablespace file id:

select count(*)
  from gv$transaction
 where ses_addr = (select saddr
                     from v$session
                    where sid = sys_context('userenv', 'sid'))
   and ubafil <> 0;

On other note for thought, I still think, there should have been a parameter or an indication elsewhere that simply indicates the setting of TEMP_UNDO_ENABLED has not had an effect, within the scope of a SESSION, not having to touch views that would otherwise be considered as administrative.

I'm open to answers if someone finds a better approach.