Le 03/05/2018 à 14:28, Andy Grove a écrit : > Now I have even more questions. > > List<List<T>> uses one values buffer for the instances of T (according to > Layout.md). > > List<Struct> couldn't possibly do that. Is that a valid type in Arrow?
I think you misread the layout document: it says a list array has """A values array, a child array of type T. T may also be a nested type""". Note: child array, not buffer. So, yes, List<Struct> is a valid type. A List<Struct> array has: * one null bitmap buffer (optional) to designate null lists * one offsets buffer for list offsets * one child struct array (which has an arbitrary number of buffers depending on the struct type) Regards Antoine.
