We are running into an issue with Druid when querying it with Plywood. We dynamically build Druid queries by allowing the user to filter the UI. Sometimes this results in the user filtering out all options (sometimes unintentionally), and is something we want to allow for.
In https://github.com/apache/incubator-druid/blob/04ea3c9f8c1f5ea34b023217bd709509ace4d30d/processing/src/main/java/io/druid/query/filter/InDimFilter.java#L78, Druid fails when filtering on empty values, though I see no reason why it should since the result should just be empty. e.g. in pseudocode,
mydatasource.filter(mycolumn in ) =
Is there a better reason for this, or can I submit a PR to remove that restriction?