Ranking Functions (U-SQL)
Summary
U-SQL provides some built-in SQL-based ranking functions that return a ranking value for each row in a partition. Depending on the function that is used, some rows might receive the same value as other rows. Ranking functions are nondeterministic.
In U-SQL, ranking functions can only be used in the following syntactic contexts:
- As a window function in a windowing expression with the OVER clause where it will calculate the value for each window partition.
Ranking functions cannot be nested.
U-SQL provides the following built-in ranking functions (follow the links for more information):
| Ranking Function | Description |
|---|---|
| DENSE_RANK | Returns the rank of rows within the partition of a window, without any gaps in the ranking. |
| NTILE | Returns the number of the group to which the row belongs from among the groups that the windowing function has distributed the rows using an ordered partition. |
| RANK | Returns the rank of each row within the window. |
| ROW_NUMBER | Returns the sequential number of a row within a window. |