ykisana opened a new pull request, #29413:
URL: https://github.com/apache/flink/pull/29413
<!--
*Thank you very much for contributing to Apache Flink - we are happy that
you want to help us improve Flink. To help the community review your
contribution in the best possible way, please go through the checklist below,
which will get the contribution into a shape in which it can be best reviewed.*
*Please understand that we do not do this to make contributions to Flink a
hassle. In order to uphold a high standard of quality for code contributions,
while at the same time managing a large number of contributions, we need
contributors to prepare the contributions well, and give reviewers enough
contextual information for the review. Please also understand that
contributions that do not follow this guide will take longer to review and thus
typically be picked up with lower priority by the community.*
## Contribution Checklist
- Make sure that the pull request corresponds to a [JIRA
issue](https://issues.apache.org/jira/projects/FLINK/issues). Exceptions are
made for typos in JavaDoc or documentation files, which need no JIRA issue.
- Name the pull request in the form "[FLINK-XXXX] [component] Title of the
pull request", where *FLINK-XXXX* should be replaced by the actual issue
number. Skip *component* if you are unsure about which is the best component.
Typo fixes that have no associated JIRA issue should be named following
this pattern: `[hotfix] [docs] Fix typo in event time introduction` or
`[hotfix] [javadocs] Expand JavaDoc for PuncuatedWatermarkGenerator`.
- Fill out the template below to describe the changes contributed by the
pull request. That will give reviewers the context they need to do the review.
- Make sure that the change passes the automated tests, i.e., `mvn clean
verify` passes. You can set up Azure Pipelines CI to do that following [this
guide](https://cwiki.apache.org/confluence/display/FLINK/Azure+Pipelines#AzurePipelines-Tutorial:SettingupAzurePipelinesforaforkoftheFlinkrepository).
- Each pull request should address only one issue, not mix up code from
multiple issues.
- Each commit in the pull request has a meaningful commit message
(including the JIRA id)
- Once all items of the checklist are addressed, remove the above text and
this checklist, leaving only the filled out template below.
**(The sections below can be removed for hotfixes of typos)**
-->
## What is the purpose of the change
Addresses: https://issues.apache.org/jira/browse/FLINK-40923
`RexSimplify` rewrote a comparison of an expression with itself (`x <op> x`)
as if `x` always equals itself: `=`, `>=`, `<=` became `x IS NOT NULL`, and
`<>`, `<`, `>` became `FALSE`. For FLOAT/DOUBLE this is wrong when `x` is NaN,
because the runtime compares NaN per IEEE 754 (`NaN = NaN` is FALSE). As a
result, the same query returned different rows depending on whether the planner
could see that both sides were the same expression. For example, with `a` and
`b` both derived from `x`, `WHERE a >= b` kept the NaN row, but dropped it
after the input was first written to a table.
## Brief change log
- `RexSimplify#simplifyComparison`: skip the reflexive-comparison rewrite
when the operand type is approximate numeric
(`SqlTypeUtil.isApproximateNumeric`), marked as a FLINK MODIFICATION in Flink's
copy of the Calcite class
- `ComparisonFunctionITCase`: added cases comparing a NaN value with itself
for all six comparison operators on DOUBLE, `=` on FLOAT, and checks that
non-NaN and NULL results are unchanged
## Verifying this change
This change added tests and can be verified as follows:
- Added cases to `ComparisonFunctionITCase` that compare `CAST('NaN' AS
DOUBLE)` / `CAST('NaN' AS FLOAT)` with itself, run through SQL and the Table
API. Without the fix, 15 cases fail (`=`, `>=`, `<=`, `<>` on DOUBLE and `=` on
FLOAT, each in 3 variants); with the fix, all 69 cases pass.
- Ran the planner's `*RuleTest` and `*CalcTest` plan tests (1,230 tests): no
plan changes.
## Does this pull request potentially affect one of the following parts:
- Dependencies (does it add or upgrade a dependency): no
- The public API, i.e., is any changed class annotated with
`@Public(Evolving)`: no
- The serializers: no
- The runtime per-record code paths (performance sensitive): no
- Anything that affects deployment or recovery: JobManager (and its
components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
- The S3 file system connector: no
## Documentation
- Does this pull request introduce a new feature? no
- If yes, how is the feature documented? not applicable
---
##### Was generative AI tooling used to co-author this PR?
<!--
If generative AI tooling has been used in the process of authoring this PR,
please
change the checkbox below to `[X]` and replace the placeholder in the
"Generated-by"
line with the tool name and version. Otherwise remove the "Generated-by"
line.
See the ASF Generative Tooling Guidance for details:
https://www.apache.org/legal/generative-tooling.html
You are responsible for the quality and correctness of every change in this
PR
regardless of the tooling used. Low-effort AI-generated PRs will be closed.
See
AGENTS.md for the full guidance.
-->
- [x] Yes (please specify the tool below)
Generated-by: Claude Opus 5.5
Tests and PR desc were done by Claude, fix was manually done by me ✋
**Note**: From working on this issue a larger issue of inconsistent NaN
comparison found throughout the codebase.
Ticket filed here: https://issues.apache.org/jira/browse/FLINK-40927
--
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]
