The vote carries with 3 binding +1 votes, 2 non-binding +1, and 1 +0 Thanks all for voting. I will update the Format PR and plan to merge the C++ PR soon thereafter
On Tue, Jun 30, 2020 at 4:00 PM Sutou Kouhei <k...@clear-code.com> wrote: > > +1 (binding) > > In <cajpuwmaghm1dv6g6j1lxsjmtfskmahg2sghkekcr0swxr-8...@mail.gmail.com> > "[VOTE] Removing validity bitmap from Arrow union types" on Mon, 29 Jun > 2020 16:23:23 -0500, > Wes McKinney <wesmck...@gmail.com> wrote: > > > Hi, > > > > As discussed on the mailing list [1], it has been proposed to remove > > the validity bitmap buffer from Union types in the columnar format > > specification and instead let value validity be determined exclusively > > by constituent arrays of the union. > > > > One of the primary motivations for this is to simplify the creation of > > unions, since constructing a validity bitmap that merges the > > information contained in the child arrays' bitmaps is quite > > complicated. > > > > Note that change breaks IPC forward compatibility for union types, > > however implementations with hitherto spec-compliant union > > implementations would be able to (at their discretion, of course) > > preserve backward compatibility for deserializing "old" union data in > > the case that the parent null count of the union is zero. The expected > > impact of this breakage is low, particularly given that Unions have > > been absent from integration testing and thus not recommended for > > anything but ephemeral serialization. > > > > Under the assumption that the MetadataVersion V4 -> V5 version bump is > > accepted, in order to protect against forward compatibility problems, > > Arrow implementations would be forbidden from serializing union types > > using the MetadataVersion::V4. > > > > A PR with the changes to Columnar.rst is at [2]. > > > > The vote will be open for at least 72 hours. > > > > [ ] +1 Accept changes to Columnar.rst (removing union validity bitmaps) > > [ ] +0 > > [ ] -1 Do not accept changes because... > > > > [1]: > > https://lists.apache.org/thread.html/r889d7532cf1e1eff74b072b4e642762ad39f4008caccef5ecde5b26e%40%3Cdev.arrow.apache.org%3E > > [2]: https://github.com/apache/arrow/pull/7535
