Hi, I couldn’t find any information in the documentation on the guarantees about the binary format compatibility for any of the sketches in the library.
For example: Given a KLL sketch generated by v4.2.0 version of the library and serialized with the Java API’s `toByteArray()` method we could have the following situations: * The sketch is guaranteed to be deserialized correctly by versions >= 4.2.0 * The sketch is guaranteed is guaranteed to be deserialized correctly by versions >=4.2.0 and <5.0.0 * The sketch is guaranteed to be deserialized correctly by versions >=4.2.0 and <4.3.0 * The sketch is guaranteed to be deserialized correctly by the version it was introduced to the library and all future versions. In this case that could mean if KLL was introduced in v4.0 but generated in v4.2, v4.0 should still be able to read it. Currently, as far as I can tell, the sketches are compatible with all versions starting with the version it was introduced but I wanted to get confirmation on whether or not this is the case. Additionally, are there guarantees the library will error or not when faced with an incompatible sketch? The example is posed specifically for KLL but applies to all sketches in the library. I am mostly interested in KLL and Theta though. Whatever the answer is, I’d happily help document it on the website if it doesn’t exist already. Cheers, Zac
