Le 25/06/2020 à 00:40, Wes McKinney a écrit : > hi folks, > > This has come up in some other contexts, but I believe it would be a > good idea to increment the version number in Schema.fbs starting with > 1.0.0 to separate the pre-1.0 and post-1.0 worlds > > https://github.com/apache/arrow/blob/master/format/Schema.fbs#L22 > > Given that we are contemplating a number of changes to assist with > forward compatibility and a breaking serialization change for unions, > this would seem prudent so that we do not risk breaking compatibility > with 0.17.1 and prior. > > Given that there are no major backwards incompatibilities, there > should be no problem with 1.0.0 readers reading data generated by > libraries <= 0.17.1.
Actually, it seems that a dense array with top-level null values (represented in 0.17.1 fashion) would need non-trivial rewriting of its offsets and child arrays (at least one child array) to represent the nulls at the child level. This is unless we keep the top-level union null bitmap in C++ and only avoid emitting it on the IPC side. Which would be a slightly weird arrangement, but would limit incompatibilites on the C++ API side. Regards Antoine.
