[druid-user] Finding out the Roll up factor


Does druid provide any way to find out that by how much factor the complete data is getting rolled up after getting ingested in druid dataSource?

For example, let’s say the number of actual events getting ingested are X but due to roll up enabled, number of rows actually stored by druid are X/2 so I’d say that roll up factor is 2 here.

This can be explicitly calculated if I know that how many actual number of events which are getting ingested. Looking for a way wherein druid itself provides this factor if it does.


If you store count as one of your ingestion aggregations (see here), then you could use sum(count)/count() after the fact.
This will give an approximation of (rows ingested)/(rows stored). (I say approximation, because by default, count(
) is
approximate in druid queries.)

Thank you for the help.