NTILE

NTILE(N)

Divides the partitioned groups into N buckets based on ordering. For example if N=3 and there are 30 rows in a partition, the first 10 are assigned 1, the next 10 are assigned 2, and the final 10 are assigned 3. In cases where the number of rows cannot be evenly divided by the number of buckets, the first buckets will have one more value than the last bucket. For example, if N=4 and there are 22 rows in a partition, the first 6 are assigned 1, the next 6 are assigned 2, the next 5 are assigned 3, and the last 5 are assigned 4.