Query to Distribute rows into even buckets.

Question

Hi Folks, requesting a SQL solution (I can't write a PL/SQL Loop).
Say I have 10 rows (10 Employe Ids) in a table.
I am trying to write a sql to evenly divide these 10 ids into X number of buckets. (if its an odd number then the last bucket will have an odd set)
lets say we divide them into 3 buckets. Following would be my output.
Now I tried using LEVEL in a WITH CLAUSE but I keep getting cartesian product.
I also tried NTILE but no help. Kindly forward me to a link or a oracle function (if any) that might help solve this.
Thank you. Aj
emp ids
buckets
1
1
2
1
3
1
4
2
5
2
6
2
7
3
8
3
9
3
10
3

Answer 1

Hi,
Please try:
with a as
select
  level id
from
  dual connect by
level <= 10
select
  id
  ,ntile(3) over (order by id) bucket
from
  a
ID BUCKET
1       1
2       1
3       1
4       1
5       2
6       2
7       2
8       3
9       3
10      3
10 rows selected
The only problem is that the oracle starts with the first bucket to divite the remaining id's over the buckets.
Theisa means bucket 1 has 4 id's and the other buckets only have 3 id's
Regards,
Peter