Evolution of a Compiling Query Engine

In 2011 we showed how to use dynamic code generation to process queries in a data-centric manner. This execution model can produce compact and efficient code and was successfully used by both our own systems and systems of other groups. As the systems become used in practice, additional techniques were developed for shortcomings that did arrive, including low-latency compilation, multi-threading support, and others. This paper gives an overview of the evolution of our query engine within in the last ten years, and points out which problem have to be tackled to bring a compiling system into production usage.