I am using Oracle GTT tables with condition ON COMMIT DELETE ROWS.
Generally GTT table's data is only session specific. One session cannot see the GTT data of other session in general.
But is their any way to access/read GTT table that belongs to another session? Is there some kind of global session.
In plain words, NO.
The definition of a temporary table is visible to all sessions, but the data in a temporary table is visible only to the session that inserts the data into the table.
Just think, if the data is visible to other sessions, the purpose of a GTT is defeated.