0lai0 opened a new pull request, #4987: URL: https://github.com/apache/datafusion-comet/pull/4987
## Which issue does this PR close? <!-- We generally require a GitHub issue to be filed for all bug fixes and enhancements and this helps us generate change logs for our releases. You can link an issue to this PR using the GitHub syntax. For example `Closes #123` indicates that this PR will close issue #123. --> Part of #4834 (DECIMAL ORDER BY only; DATE is handled in https://github.com/apache/datafusion-comet/pull/4974) ## Rationale for this change <!-- Why are you proposing this change? If this is already explained clearly in the issue then this section is not needed. Explaining clearly why changes are proposed helps reviewers understand your changes and offer better suggestions for fixes. --> Native windows used to fall back to Spark for `RANGE` frames with an explicit `PRECEDING` / `FOLLOWING` offset when `ORDER BY` was `DECIMAL`. The original reason was that Spark decimal arithmetic widens precision on `+`/`-`, so the computed boundary (e.g. `Decimal(11,0)`) no longer matched the current value's precision (e.g. `Decimal(10,0)`) and DataFusion's comparator failed with "Uncomparable values". That mismatch was fixed upstream in [apache/datafusion#22174](https://github.com/apache/datafusion/pull/22174) (closes #22113): `ScalarValue::partial_cmp` now ignores precision for `Decimal128` when the scales match. The fix ships in DataFusion 54.0.0, which Comet already pins, so DECIMAL `RANGE` boundary arithmetic runs correctly on the native side with no planner changes needed. This PR just removes the now-stale Scala fallback. `UNBOUNDED` / `CURRENT ROW` already ran natively; DATE still falls back. ## What changes are included in this PR? <!-- There is no need to duplicate the description in the issue here but it is sometimes worth providing a summary of the individual changes in this PR. --> - Scala serde: drop the `DecimalType` `RANGE` fallback; keep the DATE fallback. - No native planner change needed (upstream DataFusion already handles the boundary comparison). - Docs: remove DECIMAL from the `RANGE` fallback list in `operators.md` / `roadmap.md`, and document a `Decimal128` near-max-precision overflow difference under "Known differences". - Tests: 12 cases in `CometWindowExecSuite` (bounds combinations, duplicate values, nulls, DESC ordering, zero scale, high precision/scale, negative values crossing zero, fractional offset, `DECIMAL(38,0)` max precision). ## How are these changes tested? <!-- We typically require tests for all PRs in order to: 1. Prevent the code from being accidentally broken by subsequent changes 2. Serve as another way to document the expected behavior of the code If tests are not included in your PR, please explain why (for example, are they covered by existing tests)? --> ``` ./mvnw test -Dtest=none -Dsuites="org.apache.comet.exec.CometWindowExecSuite" ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
