CREATE PRIVATE TEMPORARY TABLE ORA$PTT_MyData_trans  
    (id      number,  
     Name  varchar2(30))  
   ON COMMIT DROP DEFINITION

insert into  ORA$PTT_MyData_trans values (1, 'john')

REM Check data before commit. 

select count(*) from ORA$PTT_MyData_trans

Commit

REM Check data after commit. 

select count(*) from ORA$PTT_MyData_trans

REM Table is available until your transaction is not committed.  

select object_name from dba_objects where object_name like 'ORA$PTT_MyData_trans'

REM Table is fully private and even does not exist in data dictionary.  

REM We can overwrite this default behaviour with below command and can preserve the definition. 

CREATE PRIVATE TEMPORARY TABLE ORA$PTT_MyData_session  
    (id      Number,  
     name  varchar2(30))  
   ON COMMIT PRESERVE DEFINITION 

insert into ORA$PTT_MyData_session values(1,'mandy')

insert into ORA$PTT_MyData_session values(1,'john')

select * from ORA$PTT_MyData_session

commit

select * from ORA$PTT_MyData_session

select object_name from dba_objects where object_name like 'ORA$PTT_MyData_session'

REM You can’t gather statistics as these tables won’t exist in data dictionary. 

exec dbms_stats.gather_table_stats('','ORA$PTT_MyData_session') 

REM Private temporary tables must be prefixed with “ORA$PTT_” and this can’t be used for regular table. 

CREATE PRIVATE TEMPORARY TABLE MyData_session  
    (id      Number,  
     name  varchar2(30))  
   ON COMMIT PRESERVE DEFINITION 

CREATE TABLE ORA$PTT_MyData_session  
    (id      Number,  
     name  varchar2(30))  
   ON COMMIT PRESERVE DEFINITION