I don't think we should couple this discussion with the implementation of
large list, etc since I think those two concepts are independent.

I've asked some others on my team their opinions on the risk here. I think
we should probably review some our more complex vector interactions and see
how the jvm's assembly changes with this kind of change. Using
microbenchmarking is good but I think we also need to see whether we're
constantly inserting additional instructions or if in most cases, this
actually doesn't impact instruction count.



On Wed, Aug 21, 2019 at 12:18 PM Micah Kornfield <emkornfi...@gmail.com>
wrote:

>
>> With regards to the reference implementation point. It is a good point.
>> I'm on vacation this week. Unless you're pushing hard on this, can we pick
>> this up and discuss more next week?
>
>
> Hi Jacques, I hope you had a good rest.  Any more thoughts on the
> reference implementation aspect of this?
>
>
>> To copy the sentiments from the 0.15.0 release thread, I think it
>> would be best to decouple this discussion from the release timeline
>> given how many people we have relying on regular releases coming out.
>> We can keep continue making major 0.x releases until we're ready to
>> release 1.0.0.
>
>
> I'm OK with it as long as other stakeholders are. Timed releases are the
> way to go.  As stated on the release thread [1] we need a better mechanism
> to avoid this type of issue arising again.  The release thread also had
> some more discussion on compatibility.
>
> Thanks,
> Micah
>
> [1]
> https://lists.apache.org/thread.html/d70feeceaf2570906ade117030b29887af7c77ca5c4a976e6d555920@%3Cdev.arrow.apache.org%3E
>
>
> On Wed, Aug 14, 2019 at 3:23 PM Wes McKinney <wesmck...@gmail.com> wrote:
>
>> On Sun, Aug 11, 2019 at 9:40 PM Micah Kornfield <emkornfi...@gmail.com>
>> wrote:
>> >
>> > Hi Wes and Jacques,
>> > See responses below.
>> >
>> > With regards to the reference implementation point. It is a good point.
>> I'm
>> > > on vacation this week. Unless you're pushing hard on this, can we
>> pick this
>> > > up and discuss more next week?
>> >
>> >
>> > Sure thing, enjoy your vacation.  I think the only practical
>> implications
>> > are it delays choices around implementing LargeList, LargeBinary,
>> > LargeString in Java, which in turn might push out the 0.15.0 release.
>> >
>>
>> To copy the sentiments from the 0.15.0 release thread, I think it
>> would be best to decouple this discussion from the release timeline
>> given how many people we have relying on regular releases coming out.
>> We can keep continue making major 0.x releases until we're ready to
>> release 1.0.0.
>>
>> > My stance on this is that I don't know how important it is for Java to
>> > > support vectors over INT32_MAX elements. The use cases enabled by
>> > > having very large arrays seem to be concentrated in the native code
>> > > world (e.g. C/C++/Rust) -- that could just be implementation-centrism
>> > > on my part, though.
>> >
>> >
>> > A data point against this view is Spark has done work to eliminate 2GB
>> > memory limits on its block sizes [1].  I don't claim to understand the
>> > implications of this. Bryan might you have any thoughts here?  I'm OK
>> with
>> > INT32_MAX, as well, I think we should think about what this means for
>> > adding Large types to Java and implications for reference
>> implementations.
>> >
>> > Thanks,
>> > Micah
>> >
>> > [1] https://issues.apache.org/jira/browse/SPARK-6235
>> >
>> > On Sun, Aug 11, 2019 at 6:31 PM Jacques Nadeau <jacq...@apache.org>
>> wrote:
>> >
>> > > Hey Micah,
>> > >
>> > > Appreciate the offer on the compiling. The reality is I'm more
>> concerned
>> > > about the unknowns than the compiling issue itself. Any time you've
>> been
>> > > tuning for a while, changing something like this could be totally
>> fine or
>> > > cause a couple of major issues. For example, we've done a very large
>> amount
>> > > of work reducing heap memory footprint of the vectors. Are target is
>> to
>> > > actually get it down to 24 bytes per ArrowBuf and 24 bytes heap per
>> vector
>> > > (not including arrow bufs).
>> > >
>> > > With regards to the reference implementation point. It is a good
>> point.
>> > > I'm on vacation this week. Unless you're pushing hard on this, can we
>> pick
>> > > this up and discuss more next week?
>> > >
>> > > thanks,
>> > > Jacques
>> > >
>> > > On Sat, Aug 10, 2019 at 7:39 PM Micah Kornfield <
>> emkornfi...@gmail.com>
>> > > wrote:
>> > >
>> > >> Hi Jacques,
>> > >> I definitely understand these concerns and this change is risky
>> because it
>> > >> is so large.  Perhaps, creating a new hierarchy, might be the
>> cleanest way
>> > >> of dealing with this.  This could have other benefits like cleaning
>> up
>> > >> some
>> > >> cruft around dictionary encode and "orphaned" method.   Per past
>> e-mail
>> > >> threads I agree it is beneficial to have 2 separate reference
>> > >> implementations that can communicate fully, and my intent here was to
>> > >> close
>> > >> that gap.
>> > >>
>> > >> Trying to
>> > >> > determine the ramifications of these changes would be challenging
>> and
>> > >> time
>> > >> > consuming against all the different ways we interact with the
>> Arrow Java
>> > >> > library.
>> > >>
>> > >>
>> > >> Understood.  I took a quick look at Dremio-OSS it seems like it has a
>> > >> simple java build system?  If it is helpful, I can try to get a fork
>> > >> running that at least compiles against this PR.  My plan would be to
>> cast
>> > >> any place that was changed to return a long back to an int, so in
>> essence
>> > >> the Dremio algorithms would reman 32-bit implementations.
>> > >>
>> > >> I don't  have the infrastructure to test this change properly from a
>> > >> distributed systems perspective, so it would still take some time
>> from
>> > >> Dremio to validate for regressions.
>> > >>
>> > >> I'm not saying I'm against this but want to make sure we've
>> > >> > explored all less disruptive options before considering changing
>> > >> something
>> > >> > this fundamental (especially when I generally hold the view that
>> large
>> > >> cell
>> > >> > counts against massive contiguous memory is an anti pattern to
>> scalable
>> > >> > analytical processing--purely subjective of course).
>> > >>
>> > >>
>> > >> I'm open to other ideas here, as well. I don't think it is out of the
>> > >> question to leave the Java implementation as 32-bit, but if we do,
>> then I
>> > >> think we should consider a different strategy for reference
>> > >> implementations.
>> > >>
>> > >> Thanks,
>> > >> Micah
>> > >>
>> > >> On Sat, Aug 10, 2019 at 5:09 PM Jacques Nadeau <jacq...@apache.org>
>> > >> wrote:
>> > >>
>> > >> > Hey Micah, I didn't have a particular path in mind. Was thinking
>> more
>> > >> along
>> > >> > the lines of extra methods as opposed to separate classes.
>> > >> >
>> > >> > Arrow hasn't historically been a place where we're writing
>> algorithms in
>> > >> > Java so the fact that they aren't there doesn't mean they don't
>> exist.
>> > >> We
>> > >> > have a large amount of code that depends on the current behavior
>> that is
>> > >> > deployed in hundreds of customer clusters (you can peruse our
>> dremio
>> > >> repo
>> > >> > to see how extensively we leverage Arrow if interested). Trying to
>> > >> > determine the ramifications of these changes would be challenging
>> and
>> > >> time
>> > >> > consuming against all the different ways we interact with the
>> Arrow Java
>> > >> > library. I'm not saying I'm against this but want to make sure
>> we've
>> > >> > explored all less disruptive options before considering changing
>> > >> something
>> > >> > this fundamental (especially when I generally hold the view that
>> large
>> > >> cell
>> > >> > counts against massive contiguous memory is an anti pattern to
>> scalable
>> > >> > analytical processing--purely subjective of course).
>> > >> >
>> > >> > On Sat, Aug 10, 2019, 4:17 PM Micah Kornfield <
>> emkornfi...@gmail.com>
>> > >> > wrote:
>> > >> >
>> > >> > > Hi Jacques,
>> > >> > > What avenue were you thinking for supporting both paths?   I
>> didn't
>> > >> want
>> > >> > > to pursue a different class hierarchy, because I felt like that
>> would
>> > >> > > effectively fork the code base, but that is potentially an
>> option that
>> > >> > > would allow us to have a complete reference implementation in
>> Java
>> > >> that
>> > >> > can
>> > >> > > fully interact with C++, without major changes to this code.
>> > >> > >
>> > >> > > For supporting both APIs on the same classes/interfaces, I think
>> they
>> > >> > > roughly fall into three categories, changes to input parameters,
>> > >> changes
>> > >> > to
>> > >> > > output parameters and algorithm changes.
>> > >> > >
>> > >> > > For inputs, changing from int to long is essentially a no-op
>> from the
>> > >> > > compiler perspective.  From the limited micro-benchmarking this
>> also
>> > >> > > doesn't seem to have a performance impact.  So we could keep two
>> > >> versions
>> > >> > > of the methods that only differ on inputs, but it is not clear
>> what
>> > >> the
>> > >> > > value of that would be.
>> > >> > >
>> > >> > > For outputs, we can't support methods "long getLength()" and "int
>> > >> > > getLength()" in the same class, so we would be forced into
>> something
>> > >> like
>> > >> > > "long getLength(boolean dummy)" which I think is a less
>> desirable.
>> > >> > >
>> > >> > > For algorithm changes, there did not appear to be too many places
>> > >> where
>> > >> > we
>> > >> > > actually loop over all elements (it is quite possible I missed
>> > >> something
>> > >> > > here), the ones that I did find I was able to mitigate
>> performance
>> > >> > > penalties as noted above.  Some of the current implementation
>> will
>> > >> get a
>> > >> > > lot slower for "large arrays", but we can likely fix those later
>> or in
>> > >> > this
>> > >> > > PR with a nested while loop instead of 2 for loops.
>> > >> > >
>> > >> > > Thanks,
>> > >> > > Micah
>> > >> > >
>> > >> > >
>> > >> > > On Saturday, August 10, 2019, Jacques Nadeau <jacq...@apache.org
>> >
>> > >> wrote:
>> > >> > >
>> > >> > >> This is a pretty massive change to the apis. I wonder how nasty
>> it
>> > >> would
>> > >> > >> be to just support both paths. Have you evaluated how complex
>> that
>> > >> > would be?
>> > >> > >>
>> > >> > >> On Wed, Aug 7, 2019 at 11:08 PM Micah Kornfield <
>> > >> emkornfi...@gmail.com>
>> > >> > >> wrote:
>> > >> > >>
>> > >> > >>> After more investigation, it looks like Float8Benchmarks at
>> least
>> > >> on my
>> > >> > >>> machine are within the range of noise.
>> > >> > >>>
>> > >> > >>> For BitVectorHelper I pushed a new commit [1], seems to bring
>> the
>> > >> > >>> BitVectorHelper benchmarks back inline (and even with some
>> > >> improvement
>> > >> > >>> for
>> > >> > >>> getNullCountBenchmark).
>> > >> > >>>
>> > >> > >>> Benchmark                                        Mode  Cnt
>>  Score
>> > >> > >>>  Error
>> > >> > >>>  Units
>> > >> > >>> BitVectorHelperBenchmarks.allBitsNullBenchmark   avgt    5
>>  3.821 ±
>> > >> > >>> 0.031
>> > >> > >>>  ns/op
>> > >> > >>> BitVectorHelperBenchmarks.getNullCountBenchmark  avgt    5
>> 14.884 ±
>> > >> > >>> 0.141
>> > >> > >>>  ns/op
>> > >> > >>>
>> > >> > >>> I applied the same pattern to other loops that I could find,
>> and for
>> > >> > any
>> > >> > >>> "for (long" loop on the critical path, I broke it up into two
>> loops.
>> > >> > the
>> > >> > >>> first loop does iteration by integer, the second finishes off
>> for
>> > >> any
>> > >> > >>> long
>> > >> > >>> values.  As a side note it seems like optimization for loops
>> using
>> > >> long
>> > >> > >>> counters at least have a semi-recent open bug for the JVM [2]
>> > >> > >>>
>> > >> > >>> Thanks,
>> > >> > >>> Micah
>> > >> > >>>
>> > >> > >>> [1]
>> > >> > >>>
>> > >> > >>>
>> > >> >
>> > >>
>> https://github.com/apache/arrow/pull/5020/commits/2ea2c1ae83e3baa7b9a99a6d06276d968df41797
>> > >> > >>> [2] https://bugs.openjdk.java.net/browse/JDK-8223051
>> > >> > >>>
>> > >> > >>> On Wed, Aug 7, 2019 at 8:11 PM Micah Kornfield <
>> > >> emkornfi...@gmail.com>
>> > >> > >>> wrote:
>> > >> > >>>
>> > >> > >>> > Indeed, the BoundChecking and CheckNullForGet variables can
>> make a
>> > >> > big
>> > >> > >>> > difference.  I didn't initially run the benchmarks with these
>> > >> turned
>> > >> > on
>> > >> > >>> > (you can see the result from above with Float8Benchmarks).
>> Here
>> > >> are
>> > >> > >>> new
>> > >> > >>> > numbers including with the flags enabled.  It looks like
>> using
>> > >> longs
>> > >> > >>> might
>> > >> > >>> > be a little bit slower, I'll see what I can do to mitigate
>> this.
>> > >> > >>> >
>> > >> > >>> > Ravindra also volunteered to try to benchmark the changes
>> with
>> > >> > Dremio's
>> > >> > >>> > code on today's sync call.
>> > >> > >>> >
>> > >> > >>> > New
>> > >> > >>> >
>> > >> > >>> > Benchmark                                        Mode  Cnt
>>  Score
>> > >> > >>>  Error
>> > >> > >>> > Units
>> > >> > >>> >
>> > >> > >>> > BitVectorHelperBenchmarks.allBitsNullBenchmark   avgt    5
>> > >>  4.176 ±
>> > >> > >>> 1.292
>> > >> > >>> > ns/op
>> > >> > >>> >
>> > >> > >>> > BitVectorHelperBenchmarks.getNullCountBenchmark  avgt    5
>> > >> 26.102 ±
>> > >> > >>> 0.700
>> > >> > >>> > ns/op
>> > >> > >>> >
>> > >> > >>> > Float8Benchmarks.copyFromBenchmark   avgt    5  7.398 ± 0.084
>> > >> us/op
>> > >> > >>> >
>> > >> > >>> > Float8Benchmarks.readWriteBenchmark  avgt    5  2.711 ± 0.057
>> > >> us/op
>> > >> > >>> >
>> > >> > >>> >
>> > >> > >>> >
>> > >> > >>> > old
>> > >> > >>> >
>> > >> > >>> > BitVectorHelperBenchmarks.allBitsNullBenchmark   avgt    5
>> > >>  3.828 ±
>> > >> > >>> 0.030
>> > >> > >>> > ns/op
>> > >> > >>> >
>> > >> > >>> > BitVectorHelperBenchmarks.getNullCountBenchmark  avgt    5
>> > >> 20.611 ±
>> > >> > >>> 0.188
>> > >> > >>> > ns/op
>> > >> > >>> >
>> > >> > >>> > Float8Benchmarks.copyFromBenchmark   avgt    5  6.597 ± 0.462
>> > >> us/op
>> > >> > >>> >
>> > >> > >>> > Float8Benchmarks.readWriteBenchmark  avgt    5  2.615 ± 0.027
>> > >> us/op
>> > >> > >>> >
>> > >> > >>> > On Wed, Aug 7, 2019 at 7:13 PM Fan Liya <
>> liya.fa...@gmail.com>
>> > >> > wrote:
>> > >> > >>> >
>> > >> > >>> >> Hi Gonzalo,
>> > >> > >>> >>
>> > >> > >>> >> Thanks for sharing the performance results.
>> > >> > >>> >> I am wondering if you have turned off the flag
>> > >> > >>> >> BoundsChecking#BOUNDS_CHECKING_ENABLED.
>> > >> > >>> >> If not, the lower throughput should be expected.
>> > >> > >>> >>
>> > >> > >>> >> Best,
>> > >> > >>> >> Liya Fan
>> > >> > >>> >>
>> > >> > >>> >> On Wed, Aug 7, 2019 at 10:23 PM Micah Kornfield <
>> > >> > >>> emkornfi...@gmail.com>
>> > >> > >>> >> wrote:
>> > >> > >>> >>
>> > >> > >>> >>> Hi Gonzalo,
>> > >> > >>> >>> Thank you for the feedback.  I wasn't aware of the JIT
>> > >> > >>> implications.   At
>> > >> > >>> >>> least on the benchmark run they don't seem to have an
>> impact.
>> > >> > >>> >>>
>> > >> > >>> >>> If there are other benchmarks that people have that can
>> > >> validate if
>> > >> > >>> this
>> > >> > >>> >>> change will be problematic I would appreciate trying to
>> run them
>> > >> > >>> with the
>> > >> > >>> >>> PR.  I will try to run the ones for zeroing/popcnt tonight
>> to
>> > >> see
>> > >> > if
>> > >> > >>> >>> there
>> > >> > >>> >>> is a change in those.
>> > >> > >>> >>>
>> > >> > >>> >>> -Micah
>> > >> > >>> >>>
>> > >> > >>> >>>
>> > >> > >>> >>>
>> > >> > >>> >>> On Wednesday, August 7, 2019, Gonzalo Ortiz Jaureguizar <
>> > >> > >>> >>> golthir...@gmail.com> wrote:
>> > >> > >>> >>>
>> > >> > >>> >>> > I would recommend to take care with this kind of changes.
>> > >> > >>> >>> >
>> > >> > >>> >>> > I didn't try Arrow in more than one year, but by then the
>> > >> > >>> performance
>> > >> > >>> >>> was
>> > >> > >>> >>> > quite bad in comparison with plain byte buffer access
>> > >> > >>> >>> > (see
>> http://git.net/apache-arrow-development/msg02353.html *)
>> > >> > and
>> > >> > >>> >>> > there are several optimizations that the JVM
>> (specifically,
>> > >> C2)
>> > >> > >>> does
>> > >> > >>> >>> not
>> > >> > >>> >>> > apply when dealing with int instead of longs. One of the
>> > >> > >>> >>> > most commons is the loop unrolling and vectorization.
>> > >> > >>> >>> >
>> > >> > >>> >>> > * It doesn't seem the best way to reference an old email
>> on
>> > >> the
>> > >> > >>> list,
>> > >> > >>> >>> but
>> > >> > >>> >>> > it is the only result shown by Google
>> > >> > >>> >>> >
>> > >> > >>> >>> > El mié., 7 ago. 2019 a las 11:42, Fan Liya (<
>> > >> > liya.fa...@gmail.com
>> > >> > >>> >)
>> > >> > >>> >>> > escribió:
>> > >> > >>> >>> >
>> > >> > >>> >>> >> Hi Micah,
>> > >> > >>> >>> >>
>> > >> > >>> >>> >> Thanks for your effort. The performance result looks
>> good.
>> > >> > >>> >>> >>
>> > >> > >>> >>> >> As you indicated, ArrowBuf will take additional 12
>> bytes (4
>> > >> > bytes
>> > >> > >>> for
>> > >> > >>> >>> each
>> > >> > >>> >>> >> of length, write index, and read index).
>> > >> > >>> >>> >> Similar overheads also exist for vectors like
>> > >> > >>> BaseFixedWidthVector,
>> > >> > >>> >>> >> BaseVariableWidthVector, etc.
>> > >> > >>> >>> >>
>> > >> > >>> >>> >> IMO, such overheads are small enough to justify the
>> change.
>> > >> > >>> >>> >> Let's check if there are other overheads.
>> > >> > >>> >>> >>
>> > >> > >>> >>> >> Best,
>> > >> > >>> >>> >> Liya Fan
>> > >> > >>> >>> >>
>> > >> > >>> >>> >> On Wed, Aug 7, 2019 at 3:30 PM Micah Kornfield <
>> > >> > >>> emkornfi...@gmail.com
>> > >> > >>> >>> >
>> > >> > >>> >>> >> wrote:
>> > >> > >>> >>> >>
>> > >> > >>> >>> >> > Hi Liya Fan,
>> > >> > >>> >>> >> > Based on the Float8Benchmark there does not seem to
>> be any
>> > >> > >>> >>> meaningful
>> > >> > >>> >>> >> > performance difference on my machine.  At least for
>> me, the
>> > >> > >>> >>> benchmarks
>> > >> > >>> >>> >> are
>> > >> > >>> >>> >> > not stable enough to say one is faster than the other
>> (I've
>> > >> > >>> pasted
>> > >> > >>> >>> >> results
>> > >> > >>> >>> >> > below).  That being said my machine isn't necessarily
>> the
>> > >> most
>> > >> > >>> >>> reliable
>> > >> > >>> >>> >> for
>> > >> > >>> >>> >> > benchmarking.
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > On an intuitive level, this makes sense to me,  for
>> the
>> > >> most
>> > >> > >>> part it
>> > >> > >>> >>> >> seems
>> > >> > >>> >>> >> > like the change just moves casting from "int" to
>> "long"
>> > >> > further
>> > >> > >>> up
>> > >> > >>> >>> the
>> > >> > >>> >>> >> > stack  for  "PlatformDepdendent" operations.  If
>> there are
>> > >> > other
>> > >> > >>> >>> >> benchmarks
>> > >> > >>> >>> >> > that you think are worth running let me know.
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > One downside performance wise I think for his change
>> is it
>> > >> > >>> >>> increases the
>> > >> > >>> >>> >> > size of ArrowBuf objects, which I suppose could
>> influence
>> > >> > cache
>> > >> > >>> >>> misses
>> > >> > >>> >>> >> at
>> > >> > >>> >>> >> > some level or increase the size of call-stacks, but
>> this
>> > >> > doesn't
>> > >> > >>> >>> seem to
>> > >> > >>> >>> >> > show up in the benchmark..
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > Thanks,
>> > >> > >>> >>> >> > Micah
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > Sample benchmark numbers:
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > [New Code]
>> > >> > >>> >>> >> > Benchmark                            Mode  Cnt   Score
>> > >>  Error
>> > >> > >>> >>> Units
>> > >> > >>> >>> >> > Float8Benchmarks.copyFromBenchmark   avgt    5
>> 15.441 ±
>> > >> 0.469
>> > >> > >>> >>> us/op
>> > >> > >>> >>> >> > Float8Benchmarks.readWriteBenchmark  avgt    5
>> 14.057 ±
>> > >> 0.115
>> > >> > >>> >>> us/op
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > [Old code]
>> > >> > >>> >>> >> > Benchmark                            Mode  Cnt   Score
>> > >>  Error
>> > >> > >>> >>> Units
>> > >> > >>> >>> >> > Float8Benchmarks.copyFromBenchmark   avgt    5
>> 16.248 ±
>> > >> 1.409
>> > >> > >>> >>> us/op
>> > >> > >>> >>> >> > Float8Benchmarks.readWriteBenchmark  avgt    5
>> 14.150 ±
>> > >> 0.084
>> > >> > >>> >>> us/op
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> > On Tue, Aug 6, 2019 at 1:18 AM Fan Liya <
>> > >> liya.fa...@gmail.com
>> > >> > >
>> > >> > >>> >>> wrote:
>> > >> > >>> >>> >> >
>> > >> > >>> >>> >> >> Hi Micah,
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >> >> Thanks a lot for doing this.
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >> >> I am a little concerned about if there is any
>> negative
>> > >> > >>> performance
>> > >> > >>> >>> >> impact
>> > >> > >>> >>> >> >> on the current 32-bit-length based applications.
>> > >> > >>> >>> >> >> Can we do some performance comparison on our existing
>> > >> > >>> benchmarks?
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >> >> Best,
>> > >> > >>> >>> >> >> Liya Fan
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >> >> On Tue, Aug 6, 2019 at 3:35 PM Micah Kornfield <
>> > >> > >>> >>> emkornfi...@gmail.com>
>> > >> > >>> >>> >> >> wrote:
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >> >>> There have been some previous discussions on the
>> mailing
>> > >> > about
>> > >> > >>> >>> >> supporting
>> > >> > >>> >>> >> >>> 64-bit lengths for  Java ValueVectors (this is what
>> the
>> > >> IPC
>> > >> > >>> >>> >> specification
>> > >> > >>> >>> >> >>> and C++ support).  I created a PR [1] that changes
>> all
>> > >> APIs
>> > >> > >>> that I
>> > >> > >>> >>> >> could
>> > >> > >>> >>> >> >>> find that take an index to take an "long" instead
>> of an
>> > >> > "int"
>> > >> > >>> (and
>> > >> > >>> >>> >> >>> similarly change "size/rowcount" APIs).
>> > >> > >>> >>> >> >>>
>> > >> > >>> >>> >> >>> It is a big change, so I think it is worth
>> discussing if
>> > >> it
>> > >> > is
>> > >> > >>> >>> >> something
>> > >> > >>> >>> >> >>> we
>> > >> > >>> >>> >> >>> still want to move forward with.  It would be nice
>> to
>> > >> come
>> > >> > to
>> > >> > >>> a
>> > >> > >>> >>> >> >>> conclusion
>> > >> > >>> >>> >> >>> quickly, ideally in the next few days, to avoid a
>> lot of
>> > >> > merge
>> > >> > >>> >>> >> conflicts.
>> > >> > >>> >>> >> >>>
>> > >> > >>> >>> >> >>> The reason I did this work now is the C++
>> implementation
>> > >> has
>> > >> > >>> added
>> > >> > >>> >>> >> >>> support
>> > >> > >>> >>> >> >>> for LargeList, LargeBinary and LargeString arrays
>> and
>> > >> based
>> > >> > on
>> > >> > >>> >>> prior
>> > >> > >>> >>> >> >>> discussions we need to have similar support in Java
>> > >> before
>> > >> > our
>> > >> > >>> >>> next
>> > >> > >>> >>> >> >>> release. Support 64-bit indexes means we can have
>> full
>> > >> > >>> >>> compatibility
>> > >> > >>> >>> >> and
>> > >> > >>> >>> >> >>> make the most use of the types in Java.
>> > >> > >>> >>> >> >>>
>> > >> > >>> >>> >> >>> Look forward to hearing feedback.
>> > >> > >>> >>> >> >>>
>> > >> > >>> >>> >> >>> Thanks,
>> > >> > >>> >>> >> >>> Micah
>> > >> > >>> >>> >> >>>
>> > >> > >>> >>> >> >>> [1] https://github.com/apache/arrow/pull/5020
>> > >> > >>> >>> >> >>>
>> > >> > >>> >>> >> >>
>> > >> > >>> >>> >>
>> > >> > >>> >>> >
>> > >> > >>> >>>
>> > >> > >>> >>
>> > >> > >>>
>> > >> > >>
>> > >> >
>> > >>
>> > >
>>
>

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