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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.