Apache Tajo

Apache Tajo was a big data warehouse build for Apache Hadoop, designed for low-latency and scalable ad-hoc queries, online aggregation, and ETL (extract-transform-load process) on large-data sets stored on HDFS (Hadoop Distributed File System) and other data sources. The product is now retired, but it is still open source and freely available (Apache 2.0 license). It's final release is version 0.11.3 from May 18, 2016.