Re: v$_ vs v_$ ?

Fan Ruo Xin wrote:

> Good! Now I understand.
> Thank you, Stan!
> Rosaline
>
> Stan wrote:
>
> > I think your getting confused here. v$_lock is a synonym for
> > sys.v_$_lock view and v$lock is a synonym for v_$lock view. Their source
> > views are totally different and hence the difference.
> >
> > so as daniel said, v_$ -- > view of x$tables and v$_ -- > synonym.
> >
> > hth,
> > -Stan
> >
> > Fan Ruo Xin wrote:
> >
> > >
> > > Daniel Morgan wrote:
> > >
> > >
> > >>Fan Ruo Xin wrote:
> > >>
> > >>
> > >>>Hi,
> > >>>What's the difference between v$_.. and v_$... ?
> > >>>Thanks for any help!
> > >>>Rosaline
> > >>>
> > >>One is a synonym and one is the actual object.
> > >>
> > >>v$_ = synonym
> > >>v_$ = view
> > >>
> > >>
> > >
> > > Then why there is a little difference between v$_lock and v_$lock?
> > > Thank you, Daniel!
> > >
> > >
> > >>you could find this out by looking at object_type in all_objects.
> > >>
> > >>Daniel Morgan
> > >>
> > >

One big difference is with respect to grants.

You can grant select on v_$ but you can not grant select on a synonym.

The synonyms are, as I understand it, present for backward compatibility. So if you are writing new code it is probably better to not use the synonyms and I would expect some minor but incremental improvement in resource utilization. Likely this is all connected to Oracle mythology originating with version 3 or something so I'll stay away from proclaiming this as a statement of fact.. ;-)

Daniel Morgan Received on Wed May 01 2002 - 10:36:57 CDT