hi Michael, this is Hongbin Ma from Apache Kylin (http://kylin.apache.org/), like James mentioned, Kylin aimed to server OLAP queries by 1. pre-aggregating raw records and save it into hbase 2. use Calcite to parse the query SQL and translate it to HBase scans.
AFAIK there're other projects doing the similar things except that they store the pre-aggregated results in ElasticSearch. However it seems not open sourced, and I believe it's not as mature and extendable as Kylin. We're also very interested in trying out different storage engine rather than HBase (like Cassandra). So if you're interested please throw a topic in our dev list. -- Regards, *Bin Mahone | 马洪宾* Apache Kylin: http://kylin.io Github: https://github.com/binmahone
