Unable to run query with multiple subqueries

Apache Druid Q&A Google Groups
#1

I am trying to run a query that has multiple sub queries :

select distinct(customer) from event_segment where country in (select val from hierarchy_segment where ancestor='Europe' and category='country') and product in (select val from hierarchy_segment where ancestor='12345' and category='product')

but getting the error:
{u'errorClass': u'io.druid.java.util.common.ISE', u'host': None, u'errorMessage': u"Cannot build plan for query: select distinct(customer) from event_segment where country in (select val from hierarchy_segment where ancestor='Europe' and category='country') and product in (select val from hierarchy_segment where ancestor='12345' and category='product')", u'error': u'Unknown exception'}

It works fine when I have only 1 subquery (‘in’ clause). Is there any other way to run this semi-join query besides running them as multiple queries?

#2

This isn’t supported today, although it’d be a nice feature. The Druid SQL planner would need some work to support multiple WHERE x IN (…) subqueries.