comphead opened a new issue, #4545:
URL: https://github.com/apache/arrow-rs/issues/4545
**Describe the bug**
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A clear and concise description of what the bug is.
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Arrow ordering use unstable sort which doesn't guarantee sort order between
same elements, this causing undesired behavior for systems that expects stable
sort
**To Reproduce**
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Steps to reproduce the behavior:
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```
#[test]
fn test_sort_primitives2() {
let n = 20;
let mut arr: [(u32, i32); 20] = [(0, 0); 20];
(0 .. n).map(|d| Some(d % 2)).enumerate().for_each(|v| arr[v.0] =
(v.0.try_into().unwrap(), v.1.unwrap()));
//println!("{:?}", arr);
sort_unstable_by::<(u32, i32), _>(&mut arr, n as usize, |a, b|
cmp(a.1, b.1).reverse());
println!("{:?}", arr.iter().filter(|v| v.1 == 1).map(|v|
v.0).collect::<Vec<_>>());
}
```
The test outputs array indices for 1 and this is correct, in sync with input
data
```
[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
```
For n = 21 which shouldn't change the output, but instead indices are messed
```
[15, 1, 3, 5, 7, 9, 11, 13, 17, 19]
```
**Expected behavior**
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A clear and concise description of what you expected to happen.
-->
**Additional context**
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Related to https://github.com/apache/arrow-rs/issues/2871
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