Apologies for the confusion, I was using wrong terminology. When I was talking about "array chunks" I meant Buffers - contiguous slices of memory with nullability, offsets, or value data.
If Arrow is not explicit about Buffers having to be memset to zero before use - whenever the size of the vale is not a multiple of its alignment we would have garbage in between, messing up the stability of a buffer-wise hash. I'm not even sure this can actually happen ... After all buffers should only carry primitive types (not some complex structs) and they all seem to be 16/32/64/128 bit long and should produce "gapless" buffers.
