Online refers to interactive queries that work and return results after submitting them, in contrast to offline or batch queries. There's no hard latency requir

Online refers to interactive queries that work and return results after submitting them, in contrast to offline or batch queries. There's no hard latency requirement and standard TPC-H data warehouse benchmark queries can take hours to run. The main advantage of Druid is that it pre-aggregates and indexes everything resulting in much smaller summarized data with fast seeks to specific rows. Materialized views, stored procedures, and ETL processes can provide the same result in relational data warehouses and come with much better SQL support as you mentioned. You should try Redshift again as it's come a long ways since the early days. Also I highly recommend MemSQL which is faster than Clickhouse with a much easier deployment, more usability and can serve OLTP workloads in the same database.