Cool idea ! Julian Feinauer ~ I think the volcano model can be used the base of the cost algorithm. As long as you define all the metadata that you care about. Another thing is that you should have a struct like RelNode and a method like #computeSelfCost.
Best, Danny Chan 在 2019年8月19日 +0800 PM5:20，Julian Feinauer <j.feina...@pragmaticminds.de>，写道： > Hi folks, > > I’m here again with another PLC4X related question (https://plc4x.apache.org). > As we have more and more usecases we encounter situations where we send LOTS > of replies to PLCs which one could sometimes optimize. > This has multiple reasons upstream (like multiple different Services sending, > or you want two logically different addresses which could be physically > equal). > > So, we consider to add some kind of optimizer which takes a Batch of requests > and tries to arrange them in an “optimal” way with regard to som cost > function. > The cost functions would of course be given by each Driver but the optimizer > could / should be rather general (possibly with pluggable rules). > > As Calcites Planner already includes all of that I ask myself if it could be > possible (and make sense) to use that in PLC4X. > Generally speaking, this raises the question if the Volcano approach can be > suitable for such problems. > The other alternative would be to start with some kind of heuristic based > planning or with other optimization algorithms (genetic algs, cross > entropy,…). > > Any thoughs or feedbacks are welcome! > > Julian
