I don't recall a ticket for the Java work but you're certainly a good candidate to take the lead on it.
On Tue, Jul 7, 2020 at 3:16 PM David Li <li.david...@gmail.com> wrote: > > I see there's ARROW-9258 to do the backwards compatibility work for > C++ and ARROW-9333 to expose this for Python; is there any ticket or > anyone planning on doing this for Java? Otherwise I'm willing to look > at it so that we can do some testing with Flight. > > Best, > David > > On 6/29/20, Wes McKinney <wesmck...@gmail.com> wrote: > > Thanks David. Indeed it seems that exposing IpcWriteOptions is going > > to be critical here. I'd like to avoid an "environment variable" > > workaround at the C++ level instead only providing such things in e.g. > > Python like we did for the alignment patch > > > > On Mon, Jun 29, 2020 at 9:30 AM David Li <li.david...@gmail.com> wrote: > >> > >> This would cause compatibility issues for Flight servers/clients > >> between versions as well. The situation is a little worse since > >> IpcWriteOptions isn't exposed and so you can't control what version > >> you write. But just exposing them in lieu of a full negotiation (which > >> we should start thinking about) should be enough to work through this. > >> > >> I see there's https://issues.apache.org/jira/browse/ARROW-8190 so I'll > >> try to tackle this soon (and do the same for Java) since it should be > >> independent of whether the format change goes through. > >> > >> Best, > >> David > >> > >> On 6/28/20, Wes McKinney <wesmck...@gmail.com> wrote: > >> > I opened a PR https://github.com/apache/arrow/pull/7566 > >> > > >> > We should prioritize getting through the other format changes, but we > >> > can vote on this in the meantime if there is consensus > >> > > >> > On Fri, Jun 26, 2020 at 2:58 PM Micah Kornfield <emkornfi...@gmail.com> > >> > wrote: > >> >> > >> >> I agree I think we have to do this given the number of changes in > >> >> flight > >> >> (especially union types). > >> >> > >> >> On Fri, Jun 26, 2020 at 7:29 AM Wes McKinney <wesmck...@gmail.com> > >> >> wrote: > >> >> > >> >> > I created a JIRA about this > >> >> > > >> >> > https://issues.apache.org/jira/browse/ARROW-9231 > >> >> > > >> >> > This issue is quite important so please take a look. > >> >> > > >> >> > On Thu, Jun 25, 2020 at 8:53 AM Wes McKinney <wesmck...@gmail.com> > >> >> > wrote: > >> >> > > > >> >> > > On Thu, Jun 25, 2020 at 5:31 AM Antoine Pitrou > >> >> > > <anto...@python.org> > >> >> > wrote: > >> >> > > > > >> >> > > > > >> >> > > > Le 25/06/2020 à 12:18, Antoine Pitrou a écrit : > >> >> > > > > > >> >> > > > > Le 25/06/2020 à 00:40, Wes McKinney a écrit : > >> >> > > > >> hi folks, > >> >> > > > >> > >> >> > > > >> This has come up in some other contexts, but I believe it > >> >> > > > >> would > >> >> > > > >> be a > >> >> > > > >> good idea to increment the version number in Schema.fbs > >> >> > > > >> starting > >> >> > with > >> >> > > > >> 1.0.0 to separate the pre-1.0 and post-1.0 worlds > >> >> > > > >> > >> >> > > > >> https://github.com/apache/arrow/blob/master/format/Schema.fbs#L22 > >> >> > > > >> > >> >> > > > >> Given that we are contemplating a number of changes to assist > >> >> > > > >> with > >> >> > > > >> forward compatibility and a breaking serialization change for > >> >> > unions, > >> >> > > > >> this would seem prudent so that we do not risk breaking > >> >> > compatibility > >> >> > > > >> with 0.17.1 and prior. > >> >> > > > >> > >> >> > > > >> Given that there are no major backwards incompatibilities, > >> >> > > > >> there > >> >> > > > >> should be no problem with 1.0.0 readers reading data > >> >> > > > >> generated > >> >> > > > >> by > >> >> > > > >> libraries <= 0.17.1. > >> >> > > > > > >> >> > > > > Actually, it seems that a dense array with top-level null > >> >> > > > > values > >> >> > > > > (represented in 0.17.1 fashion) would need non-trivial > >> >> > > > > rewriting > >> >> > > > > of > >> >> > its > >> >> > > > > offsets and child arrays (at least one child array) to > >> >> > > > > represent > >> >> > > > > the > >> >> > > > > nulls at the child level. > >> >> > > > > > >> >> > > > > This is unless we keep the top-level union null bitmap in C++ > >> >> > > > > and > >> >> > only > >> >> > > > > avoid emitting it on the IPC side. Which would be a slightly > >> >> > > > > weird > >> >> > > > > arrangement, but would limit incompatibilites on the C++ API > >> >> > > > > side. > >> >> > > > > >> >> > > > Actually, if we do this, the same problem will appear on the IPC > >> >> > > > write > >> >> > > > side (C++-created dense union arrays with a top-level null > >> >> > > > bitmap > >> >> > > > will > >> >> > > > need regenerating some of the child buffers). > >> >> > > > >> >> > > I see. Well I think we can shut down this issue by giving up on > >> >> > > Union > >> >> > > forward compatibility V4 / pre-1.0 libraries. > >> >> > > > >> >> > > > Regards > >> >> > > > > >> >> > > > Antoine. > >> >> > > >> > > >
