Case classes ate my RAM - Roman Grebennikov

Roman Grebennikov dives into JVM memory layout to explain the overhead of Scala case classes and collections, presenting a packed array alternative.

Roman Grebennikov ( twitter.com/@public_void_grv) Case class is a most widely used way to model your data. But when the data is huge, you can amazingly discover that only a tiny 10% of your precious RAM used for the data itself. But where is other 90%? During this talk, you will have a deep dive to the JVM internals learning about case class layout, Scala collections true memory overhead and ways to decrease it. We’ll introduce a scala-packed, the project helped Findify to solve a real-life case of reducing memory usage by an order of magnitude by extending Scala collections with transparent Shapeless-based case class <-> Array[Byte] packing.