S="LITERAL"
>INSTEAD OF</TT
> trigger on the view.
    Rewriting works slightly differently
    in this case.  For <TT
CLASS="COMMAND"
>INSERT</TT
>, the rewriter does
    nothing at all with the view, leaving it as the result relation
    for the query.  For <TT
CLASS="COMMAND"
>UPDATE</TT
> and
    <TT
CLASS="COMMAND"
>DELETE</TT
>, it's still necessary to expand the
    view query to produce the <SPAN
CLASS="QUOTE"
>"old"</SPAN
> rows that the command will
    attempt to update or delete.  So the view is