Desired to know the different between session duration & call duration used with dbms_lob.createtemp

declaration:

DBMS_LOB.CREATETEMPORARY (

   lob_loc IN OUT NOCOPY CLOB CHARACTER SET ANY_CS,

   cache   IN            BOOLEAN,

   dur     IN            PLS_INTEGER := 10)

  

the dbms_lob.createtemporary() has two available values for its dur parameters

DBMS_LOB.SESSION: the temporary LOB is cleaned up at the end of the session

DBMS_LOB.CALL: the temporary LOB is cleaned up at the end of the call

I need to know the difference between them, so I do the following tests but the result shows that they did not.

--with DBMS_LOB.CALL

variable clb clob;

variable ch varchar2(4000);

variable k number;

exec dbms_lob.createtemporary(:clb,true,dbms_lob.call);