Any idea why Druid performed so poorly though? 100x slower seems odd. I though druid was reasonably good at single table analytics like in this benchmark. Is it the small data size?
Hard to say why more of a difference shows up here, since I haven't analyzed the benchmark. It's possible the Druid configuration is suboptimal in some way. It's also possible it has something to do with the setup. It appears that the ClickHouse tests were done using a local table, which there isn't an equivalent of in Druid. Druid treats every table like what ClickHouse would call a "distributed" table. My understanding is using a distributed table in ClickHouse adds overhead since the system can no longer assume all data is on a single server. It may be that using distributed queries in both systems would yield a different result. And of course it may be that some of the test queries exercise functionality where ClickHouse is legitimately better optimized. But, again, hard to say anything for certain without detailed analysis.