Dcount
dcount
Returns an approximate count of distinct values in a column.
Spec
dcount(arg0)Parameters
arg0 - The column to count distinct values of.Return Value
An int64 estimate of the number of distinct non-null values. The implementation uses
an exact sparse state for small sets and transitions to a p=14 HyperLogLog-family state
with approximately 1% standard error. Hashing is deterministic across processes.Example
datatable(val:string)["a", "b", "a", "c", "b"]
| summarize unique_count = dcount(val)| unique_count |
|---|
| 3 |