Thanks for the reply. But It is not clear from the point of view of usability. Which one sould be used and where ?

select * from v$session where audsid = userenv('sessionid');
returns a row

But
select * from v$session where audsid = userenv('sessionid');
does not return any row.

So it implies that sid column has different meaning to Oracle. So in which cases sid column can be used ?

reagrds

Deba