Le 24/06/2020 à 16:57, Wes McKinney a écrit : > hi folks, > > As discussed on the recent GitHub PR [1], as a means of reconciling > the long-standing cross-implementation incompatibilities with Union > types, it's been proposed to remove the top-level validity bitmap from > the Union data layout and let validity be determined exclusively by > the child arrays of the union. So the only additional data needed to > form a union are the type ids (and for the dense union, the offsets). > > I do not think this change meaningfully alters the semantics of Union > types and I think it also simplifies their construction, so I would be > in favor of making it for 1.0.0.
So it sounds like this may break compatibility with existing only uses of Arrow C++ (and the relevant bindings: PyArrow, Arrow C/GLib, Red Arrow); not only on the API side, but on the data side. Regards Antoine.