> Is it jus the late hour or they are not using any code generation for their > query execution engine? > The GroupBy execution for instance looks quite complex, and doesn't look very > efficient, since it was written generically,
Sorry if this doesn't actually thread properly, I apparently fail at being able to reply to messages that were sent before I joined the list. Just wanted to respond here. Yes, it's true that we aren't using code generation for our queries. It's also true that the GroupBy implementation is not optimal. Our benchmarks are based on a timeseries-specific query that is still tangled up with internal stuff and so has not been added to the OSS release yet. The GroupBy implementation is there as a first pass at something to allow for it to just function and us to explore and squash the higher order bugs related to memory management and streaming of results back up to the query broker. Code generation is definitely on our roadmap for potential ways to optimize query execution, but it has not been the highest priority especially given that for our other query types (like the timeseries query that is yet to open up), just relying on JIT-compilation of pure Java has been plenty fast and probably easier to maintain (I say probably, 'cause I don't really know how hard it would be to maintain the code-generated solution as we haven't done it). --Eric
