Don't allocate Arrow validity buffers
They are only needed when values can be None; and here they can't.
This saves 1 bit for each 8-bytes integer or path, and simplifies computation of memory usage (which a future commit will introduce)
Staging instance, all changes can be removed at any time
They are only needed when values can be None; and here they can't.
This saves 1 bit for each 8-bytes integer or path, and simplifies computation of memory usage (which a future commit will introduce)