The "Duplicate field name" check on inputRowSignature is too strict: it is actually fine for a row signature to have the same field name twice. It happens when the same expression is selected twice, and both selections map to the same Druid object (dimension, aggregator, etc).
I did not succeed in writing a test that triggers this, but I did see it occur in production for a complex query with hundreds of aggregators. [ Full content available at: https://github.com/apache/incubator-druid/pull/6403 ] This message was relayed via gitbox.apache.org for [email protected]
