of rows. The fact that
    one is a <TT
CLASS="COMMAND"
>SELECT</TT
> command and the other is an
    <TT
CLASS="COMMAND"
>UPDATE</TT
> is handled higher up in the executor, where
    it knows that this is an <TT
CLASS="COMMAND"
>UPDATE</TT
>, and it knows that
    this result should go into table <TT
CLASS="LITERAL"
>t1</TT
>. But which of the rows
    that are there has to be replaced by the new row?</P
><P
>    To resolve this problem, another entry is added to the target list
    in <TT
CLASS="COMMAND"
