@polskibus, Heterogeneous can mean different things. Drill attacks problems where there is no well defined schema. Other heterogeneous data source tools are m

@polskibus, Heterogeneous can mean different things. Drill attacks problems where there is no well defined schema. Other heterogeneous data source tools are more about accessing different data sources, all relational. To do what Drill does requires that SQL be changed from a statically typed language to a dynamically typed language that generates code on the fly. Drill also does this in parallel.