Druid Default Distinct Approximation Algorithm

Question

Is there a way to modify the default HLL approximation algorithm with ThetaSketch in Druid? So that while querying for count distinct, druid by default uses ThetaSketch instead of HLL.

Answer 1

I believe you need to be explicit at query time, e.g. using APPROX_COUNT_DISTINCT_DS_THETA versus APPROX_COUNT_DISTINCT_DS_HLL

https://druid.apache.org/docs/latest/querying/sql.html#aggregation-functions