Re: Select * in exists subq. (Was: Update table without where exists( subquery) ?

Roland Svensson <roland.svensson_at_localhost> wrote in message news:cro8eskjknuffshjffn9l4cmjcj9504qb1_at_4ax.com...
> On Thu, 30 Mar 2000 21:22:45 +0200, "Sybrand Bakker"
> <postbus_at_sybrandb.demon.nl> wrote:
> >
> >First of all, replace the * in your subquery by a 'x'. You are now
forcing
> >Oracle to retrieve the row, using 'x' it won't retrieve the row.
> >
>
> Is this really true? Explain will not show any table access for an
> exists subquery no matter what you put in the column-list (if there
> is a proper index). Optimizer seems to be smart enough to recognise
> 'exists' and skip all unnecessary row retrieval.
>
>
> --
> Regards,
> Roland

In that case the beheavior has changed. In Oracle 7 my statement definitely is true.
Regards,

Sybrand Bakker, Oracle DBA Received on Fri Mar 31 2000 - 04:04:10 CST