Why

Arrow unions has downsides:

• slow serialization/deserialization (no zero-copy)
• hard to codegen (especially for Python)
• complex for users that want the raw arrow data

TODO

• TimeRangeBoundary
• TensorBuffer

Related

• Roundtrip tests should give better error message on union-type mismatch #3410
• Split Transform3D component union type into components #6831
• Refactor Tensor and Image archetypes #6844
• Replace TensorBuffer with datatype generics #9119