You're required to write either RANGE or ROWS to start a frame clause,
but the documentation incorrectly implied this is optional. Noted by
David Johnston.
The <replaceable class="parameter">frame_clause</> can be one of
<synopsis>
-[ RANGE | ROWS ] <replaceable>frame_start</>
-[ RANGE | ROWS ] BETWEEN <replaceable>frame_start</> AND <replaceable>frame_end</>
+{ RANGE | ROWS } <replaceable>frame_start</>
+{ RANGE | ROWS } BETWEEN <replaceable>frame_start</> AND <replaceable>frame_end</>
</synopsis>
where <replaceable>frame_start</> and <replaceable>frame_end</> can be
and the optional <replaceable class="parameter">frame_clause</replaceable>
can be one of
<synopsis>
-[ RANGE | ROWS ] <replaceable>frame_start</>
-[ RANGE | ROWS ] BETWEEN <replaceable>frame_start</> AND <replaceable>frame_end</>
+{ RANGE | ROWS } <replaceable>frame_start</>
+{ RANGE | ROWS } BETWEEN <replaceable>frame_start</> AND <replaceable>frame_end</>
</synopsis>
where <replaceable>frame_start</> and <replaceable>frame_end</> can be
one of