hyperUnique value occasionally changed


I use hyperUnique. But result value is changed between two values. ( 762,620 / 762,806 )

How can I get unchanging value?

See this thread for explanation: https://groups.google.com/d/topic/druid-user/ZToS-udQo5k/discussion


Hi Kyle

I tried below setting but nothing changed.

“context”: {

“groupByIsSingleThreaded”: true


any other settings needed?

Hi Jay,

Our hyperUnique algorithm can give varying results based on the order in which segments are processed, and Druid does not guarantee any particular ordering for processing of segments. Since it’s an approximation, hopefully you can find it in your heart to accept that the results will potentially vary from query to query. If it’s not acceptable, maybe you want to do an exact unique count, which you can do with a groupBy subquery or by setting “useApproximateCountDistinct: false” in Druid SQL.