How would using the typeid directly work with arbitrary Extension types? -Keith
On Fri, Aug 13, 2021 at 12:49 PM Jorge Cardoso Leitão < jorgecarlei...@gmail.com> wrote: > Hi, > > In the UnionArray, there is a level of indirection between types (buffer of > i8s) -> typeId (i8) -> field. For example, the generated_union part of our > integration tests has the data: > > types: [5, 5, 5, 5, 7, 7, 7, 7, 5, 5, 7] (len = 11) > typeids: [5, 7] > fields: [int32, utf8] > > My understanding is that, to get the field of item 4, we read types[4] (7), > look for the index of it in typeids (1), and take the field of index 1 > (utf8), and then read the value (4 or other depending on sparsess). > > Does someone know the rationale for the intermediare typeid? I.e. couldn't > the types contain the index of the field directly [0, 0, 0, 0, 1, 1, 1, 1, > 0, 0,1] (replace 5 by 0, 7 by 1, and not use typeids)? > > Best, > Jorge >
