hll_merge()
Merges hll results (scalar version of the aggregate version hll_merge()).
Read about the underlying algorithm (HyperLogLog) and estimation accuracy.
Syntax
hll_merge( Expr1, Expr2, ...)
Arguments
- Columns that have
hllvalues to be merged.
Returns
The result for merging the columns *Exrp1*, *Expr2*, ... *ExprN* to one hll value.
Examples
range x from 1 to 10 step 1
| extend y = x + 10
| summarize hll_x = hll(x), hll_y = hll(y)
| project merged = hll_merge(hll_x, hll_y)
| project dcount_hll(merged)
dcount_hll_merged |
|---|
| 20 |