kiszk/gist:daedf1e033a07d3f484655a69aac78ca

## gistfile1.txt
Micah, thank you for expanding the scope for Big Endian support in Arrow. I am happy to see this when I am back from one-week vacation. I agree with this since we have just seen the kickoff of BE support in Go. Let me make comments

> 1.  As long as there is CI in place to catch regressions (right now I think the CI is fairly unreliable?)
I agree. While TravisCI on s390x are unreliable, each platform can set up CI script.

> 2.  No degradation in performance for little-endian architectures (verified by additional micro benchmarks)
Yes, we can do it. @kou suggested me to use the existing mechanism like [1]. Now, it supports C++.We could expand this to other languages.

> 3.  Not a large amount of invasive code to distinguish between platforms.
Yes, I will prepare a draft of the principle for endian-independent code in another mail.

> Kazuaki Ishizaki I asked question previously, but could you give some data points around:
Sorry for the delay. I was waiting for comments during my one-week vacation.

> 1.  The current state of C++ support (how much code needed to change)?
In my understanding, the PR [2] is the last PR to support big-endian for intra-process and inter-process in C++ except Parquet support.

> 2.  How many more PRs you expect to need for Java (and approximate size)?
I have just submitted two PRs [5, 6] today to pass the current test using “mvn install”. The total size of the four PRs [3, 4, 5, 6] are around 200 lines. For CI for Java, I submitted one PR [7] (~100 lines).
In addition, I will submit another PR (~500 lines) to pass integration test.

BTW, I think that it would be good to add test cases to increase test coverage for little-endian and big-endian (e.g. increase the types of a schema to be tested in flight-core). If it is acceptable, we can submit more PRs regardless of endianness.

[1] https://github.com/apache/arrow/pull/7940#issuecomment-672690540
[2] https://github.com/apache/arrow/pull/7507
[3] https://github.com/apache/arrow/pull/7942
[4] https://github.com/apache/arrow/pull/7944
[5] https://github.com/apache/arrow/pull/8056
[6] https://github.com/apache/arrow/pull/8057
[7] https://github.com/apache/arrow/pull/7938
	Micah, thank you for expanding the scope for Big Endian support in Arrow. I am happy to see this when I am back from one-week vacation. I agree with this since we have just seen the kickoff of BE support in Go. Let me make comments

	> 1. As long as there is CI in place to catch regressions (right now I think the CI is fairly unreliable?)
	I agree. While TravisCI on s390x are unreliable, each platform can set up CI script.

	> 2. No degradation in performance for little-endian architectures (verified by additional micro benchmarks)
	Yes, we can do it. @kou suggested me to use the existing mechanism like [1]. Now, it supports C++.We could expand this to other languages.

	> 3. Not a large amount of invasive code to distinguish between platforms.
	Yes, I will prepare a draft of the principle for endian-independent code in another mail.

	> Kazuaki Ishizaki I asked question previously, but could you give some data points around:
	Sorry for the delay. I was waiting for comments during my one-week vacation.

	> 1. The current state of C++ support (how much code needed to change)?
	In my understanding, the PR [2] is the last PR to support big-endian for intra-process and inter-process in C++ except Parquet support.

	> 2. How many more PRs you expect to need for Java (and approximate size)?
	I have just submitted two PRs [5, 6] today to pass the current test using “mvn install”. The total size of the four PRs [3, 4, 5, 6] are around 200 lines. For CI for Java, I submitted one PR [7] (~100 lines).
	In addition, I will submit another PR (~500 lines) to pass integration test.

	BTW, I think that it would be good to add test cases to increase test coverage for little-endian and big-endian (e.g. increase the types of a schema to be tested in flight-core). If it is acceptable, we can submit more PRs regardless of endianness.

	[1] https://github.com/apache/arrow/pull/7940#issuecomment-672690540
	[2] https://github.com/apache/arrow/pull/7507
	[3] https://github.com/apache/arrow/pull/7942
	[4] https://github.com/apache/arrow/pull/7944
	[5] https://github.com/apache/arrow/pull/8056
	[6] https://github.com/apache/arrow/pull/8057
	[7] https://github.com/apache/arrow/pull/7938