GH-29642: [R] Support for .keep_all = TRUE with distinct()

[nealrichardson]

Rationale for this change

Support a missing feature, just wiring up some stuff from R to Acero, then adding docs and tests.

This is mostly picking up where #13934 started and finishing it out. Thanks @mopcup for the initial lift.

What changes are included in this PR?

An aggregation binding, some symbol manipulation, and tests. I also cleaned up some dplyr test shims from 2022.

Are these changes tested?

Yes, though if anyone knows of odd corners in distinct() that aren't covered by this, we can add more

Are there any user-facing changes?

Yes indeed.

• GitHub Issue: [R] Support for .keep_all = TRUE with distinct()  #29642

[github-actions]

⚠️ GitHub issue #29642 has been automatically assigned in GitHub to PR creator.

[jonkeane]

Thanks for this! Mostly questions about messaging + conveying some of the nuances

[jonkeane]

Is 110-111 the error that someone would get if they tried distinct(..., .keep_all = TRUE) with a factor in the table/data.frame?

We might want to make that a bit nicer / more grokable for folks who might not have the dictionary -> factor knowledge top of mind

[nealrichardson]

Yeah that's the error message. I'd have to think about how/where best to catch that and translate that to R-speak. As it turns out, dictionary isn't the only unsupported type, it's just the only one we have in this test data frame. I think list types and other non-simple types are also not supported, IIRC from RTFS.

[nealrichardson]

#44740

[jonkeane]

This behavior change is probably either not-impactful, or if folks are relying on it, that is actually a bug in their code. Though it does seem like something we should mention (in docs at least?).

Or maybe with a one-time warning?

[nealrichardson]

It is documented on the acero man page, that's the change to arrow-package.R. I'd rather not one-time warning; that's a slippery slope if we were going to be chatty about every subtle difference between how Acero works from dplyr on data.frames.

[rkrug]

Is there any chance to get it merged? I would very much need to use it in my code!

Thanks.

[jonkeane]

My last review should have been an approve with comments rather than just a comment

[rkrug]

Thanks. So it will be in the next release?

[jonkeane]

It missed the latest release, but once it merges it'll be in the following one. Alternatively, you could use nightly builds starting the day after it merges.

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 3 benchmarking runs that have been run so far on merge-commit 1b3caf6.

There were 132 benchmark results with an error:

• Commit Run on arm64-t4g-2xlarge-linux at 2024-12-07 16:34:43Z
  • tpch (R) with engine=arrow, format=parquet, language=R, memory_map=False, query_id=TPCH-07, scale_factor=1
  • tpch (R) with engine=arrow, format=native, language=R, memory_map=False, query_id=TPCH-09, scale_factor=1
• and 130 more (see the report linked below)

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 1 possible false positive for unstable benchmarks that are known to sometimes produce them.