HLL_EMPTY
Description
HLL_EMPTY
returns an empty HLL (HyperLogLog) value, representing a data set with no elements.
Syntax
HLL_EMPTY()
Return Value
Returns an empty HLL type value, representing a data set with no elements.
Example
select hll_cardinality(hll_empty());
+------------------------------+
| hll_cardinality(hll_empty()) |
+------------------------------+
| 0 |
+------------------------------+