select sum(age)/sum(age2) from (select age from tbname where rownum<11),(select age age2 from tbname);
SELECT * FROM TNAME WHERE ROWNUM<11;
select a.top_nalues/b.all_values from (select sum(values) top_values from tname where rownum<11 order by desc ) a, (select sum(values) all_values from tname) b
SELECT (SELECT SUM(A.COL1) FROM A WHERE ROWNUM<5)/(SELECT SUM(A.COL1) FROM A) FROM DUAL
(select sum(values) top_values from tname where rownum<11 order by desc ) a,
(select sum(values) all_values from tname) b
(SELECT SUM(A.COL1) FROM A WHERE ROWNUM<5)/(SELECT SUM(A.COL1) FROM A)
FROM DUAL