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APPROX_COUNT_DISTINCT_ACCUMULATE
An aggregate function. For a collection of values, it creates a new HyperLogLog state and returns a value representing the new state.
Syntax
APPROX_COUNT_DISTINCT_ACCUMULATE ( expr )
Arguments
expr
An expression evaluating to a scalar value.
expr is typically the name of a column. In this case, APPROX_COUNT_DISTINCT_ACCUMULATE uses values in the column to create a new HyperLogLog state.
Remarks
This function is used in conjuction with APPROX_COUNT_DISTINCT_COMBINE and APPROX_COUNT_DISTINCT_ESTIMATE. To best understand its usage, see the topic Distinct Count Estimation Functions.
