ipsyer opened a new pull request, #28874: URL: https://github.com/apache/flink/pull/28874
## What is the purpose of the change The Window Top-N examples display final results for two tumbling windows, but the example input does not advance the watermark far enough to close the second window in unbounded streaming mode. With the documented watermark strategy, the maximum event timestamp `08:17` produces a watermark of approximately `08:16:59`. Therefore, the `[08:10, 08:20)` window remains open, and its final Window Top-N result is not emitted. This change clarifies the execution conditions required to reproduce the displayed results. JIRA: https://issues.apache.org/jira/browse/FLINK-40289 ## Brief change log * Add an informational note after the Window Top-N SQL example. * Explain that bounded input closes the remaining windows at the end of input. * Explain that unbounded streaming input requires subsequent records to advance the watermark past the window end. * Apply the same clarification to the English and Chinese documentation. * Keep the existing SQL examples and result tables unchanged. * A follow-up backport to `release-1.20` will be submitted separately. ## Verifying this change This is a documentation-only change. No tests were added. The watermark behavior was manually verified using the documented input: * The maximum event timestamp is `2020-04-15 08:17:00.000`. * With a one-second watermark delay, the watermark reaches approximately `2020-04-15 08:16:59.000`. * The `[08:00, 08:10)` window closes. * The `[08:10, 08:20)` window remains open in unbounded streaming mode unless subsequent records advance the watermark past its end. * The information blocks are placed outside the SQL code fences in both the English and Chinese documentation. ## 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: 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; this PR clarifies existing documentation --- ##### Was generative AI tooling used to co-author this PR? * [x] Yes (OpenAI Codex) Generated-by: OpenAI Codex -- 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]
