These all sound good to me On Mon, Sep 29, 2025, 6:34 PM Lee Rhodes <[email protected]> wrote:
> The upcoming 9.0.0 release of the DataSketches-java library is providing > an opportunity to clean up and refactor some things in the existing code > that should make the code base easier to understand and use. > > Some of the code has been around for over 10 years and the library has > changed considerably since then. This note is an early heads-up into some > of the major changes coming to the library. A more complete summary of the > changes will be published at the time of release. > > - Java 25 is the first Java LTS release of the FFM API, and provides > an amazing opportunity for us to obsolete the entire DataSketches-Memory > repository. The DS-Memory repo has served us well for over 10 years by > providing fast access to off-heap data structures. But FFM now provides > that capability directly as part of the Java language. And, as a result, > DS-Memory will be completely replaced with FFM in the DS-Java 9.0.0 > release. > > Our backward compatibility promise is primarily focused on the binary > compatibility of being able to read serializations of earlier versions of > the code with our latest versions. This is still true. However, up until > recently we have been supporting binary compatibility with very early code > versions at Yahoo that existed long before our code was first open-sourced > in August of 2015 (we became part of ASF in 2020). Since Yahoo is in the > process of obsoleting those systems that used some of that code there is no > reason that we need to keep supporting it. > > - With DS-Java 9.0.0, we plan to remove the complex code that allowed > us to read that old code. If someone, for some reason, should need to read > sketches serialized prior to August of 2015, it is still possible to do so > with DS-java versions prior to 9.0.0, e.g., 8.0.0. Those sketches can then > be re-serialized, which will be able to be read with DS-Java 9.0.0 and > beyond. > > The Theta Sketch family was our first family of sketches that we > developed, and as a result it has some peculiarities. For example, the > root class is called "Sketch" (because it was the only one). As we > developed other sketch families, we made the root class names carry more > meaningful information, e.g., HllSketch, CpcSketch, KllSketch, etc. > > - With DS-Java 9.0.0, we will be bringing the Theta Sketch family up > to the same standard as the other sketches, so the root class will be > called ThetaSketch, and the names of its child classes will be named > accordingly. > > The Theta Sketch family is one of the largest families of sketches with > many classes, many of which just "evolved" -- and unfortunately, with a > lot of duplication and incomplete coverage. It is hard to understand all > the relationships and where to find the function you might be looking for. > > - With DS-Java 9.0.0, we will try to remove much of the duplication > and provide some better documentation to help you find your way around. > > We would certainly like to hear from you. > > > > >
