I'm the main dev of TiSpark. I totally agree. For now we allow trx only in TiDB. I believe one day those big-data stuff will be unified onto one platform. With a full-featured distributed db storage layer underneath, there might be tons of tricks to play comparing to data on hdfs. Ultimately, we plan to put a mysql layer on top of Spark SQL (maybe or something else as mpp engine), as you said, to make user not aware of existence of Spark SQL underneath.