JasonLi-cn opened a new pull request, #10006:
URL: https://github.com/apache/arrow-datafusion/pull/10006
## Which issue does this PR close?
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Closes #.
## Rationale for this change
If the `trim` function includes a second argument, I believe it is
predominantly a Scalar rather than an Array. Expanding the second argument into
an Array would lead to performance degradation, and more critically, the code
`arg.clone().into_array(expansion_len)` would be invoked for every computation.
### Benchmark
```shell
Gnuplot not found, using plotters backend
ltrim ": 1024 time: [23.495 µs 23.520 µs 23.554 µs]
change: [-11.992% -11.922% -11.854%] (p = 0.00 <
0.05)
Performance has improved.
Found 2 outliers among 100 measurements (2.00%)
2 (2.00%) high severe
ltrim ": 4096 time: [92.348 µs 92.489 µs 92.669 µs]
change: [-10.305% -10.123% -9.9762%] (p = 0.00 <
0.05)
Performance has improved.
Found 15 outliers among 100 measurements (15.00%)
6 (6.00%) high mild
9 (9.00%) high severe
ltrim ": 8192 time: [189.78 µs 190.59 µs 191.57 µs]
change: [-6.1871% -5.8626% -5.5516%] (p = 0.00 <
0.05)
Performance has improved.
ltrim Header:: 1024 time: [80.256 µs 80.276 µs 80.300 µs]
change: [-7.5562% -7.0325% -6.6364%] (p = 0.00 <
0.05)
Performance has improved.
ltrim Header:: 4096 time: [318.94 µs 319.04 µs 319.15 µs]
change: [-5.5723% -5.4562% -5.3322%] (p = 0.00 <
0.05)
Performance has improved.
Found 3 outliers among 100 measurements (3.00%)
2 (2.00%) high mild
1 (1.00%) high severe
ltrim Header:: 8192 time: [643.04 µs 643.69 µs 644.34 µs]
change: [-4.9289% -4.7291% -4.5327%] (p = 0.00 <
0.05)
Performance has improved.
Found 3 outliers among 100 measurements (3.00%)
1 (1.00%) high mild
2 (2.00%) high severe
```
## What changes are included in this PR?
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## Are these changes tested?
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## Are there any user-facing changes?
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