nope, I was thinking about it *wrong*
I wasn't thinking about analytics of an aggregation, but analytics in general:
ops$tkyte%ORA10GR2> select deptno, sum(sal) over () from scott.emp group by deptno;
select deptno, sum(sal) over () from scott.emp group by deptno
*
ERROR at line 1:
ORA-00979: not a GROUP BY expression
if you analytic an aggregate - it works OK
ops$tkyte%ORA10GR2> select deptno, sum(sum(sal)) over () from scott.emp group by deptno;
DEPTNO SUM(SUM(SAL))OVER()
---------- -------------------
10 118763.25
20 118763.25
30 118763.25
but I did not think of it like that - because I would not myself write the query that way - I would have used an inline view
select deptno, sum(sum_sal) over ()
from (select deptno, sum(sal) sum_sal from emp group by deptno)
(matter of style made me miss this one)