2010YOUY01 opened a new pull request, #15469: URL: https://github.com/apache/datafusion/pull/15469
## 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. --> related to https://github.com/apache/datafusion/issues/15372 ## 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. --> One external sort query will panic due to an assertion failure ### Reproducer Compile and run `datafusion-cli` commit 46f40245 ``` > set datafusion.execution.sort_spill_reservation_bytes = 0; > select * from generate_series(1, 10000000) as t1(v1) order by v1; thread 'tokio-runtime-worker' panicked at datafusion/physical-plan/src/sorts/sort.rs:406:9: assertion failed: self.in_mem_batches_sorted note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace ``` For background knowledge for external sort, check the doc in https://github.com/apache/datafusion/blob/46f4024577f4e13b79d8739849ecf51af5ddc7c2/datafusion/physical-plan/src/sorts/sort.rs#L80 Now a single field `in_mem_batches` is used to represent buffered data in different stage: during different time, it can be interpreted as either unordered input batch, or globally sorted batch, a state flag `self.in_mem_batches_sorted` is used to represent its sorted-ness and do extra sanity checks. This approach has poor understandability and is also error-prone, and actually triggered one edge case assertion failure. Note the execution logic is not wrong, the issue is this flag is set too late. To also address https://github.com/apache/datafusion/issues/15372, this PR did a small refactor to make the related logic more understandable: ## 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. --> refactor to let `ExternalSorter.in_mem_batches` to only hold unsorted input batches (instead of representing both sorted and unsorted batches during different execution stage, as it's doing before the PR) ## 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)? --> A unit test was added to cover the edge case that previously triggered an assertion failure. ## Are there any user-facing changes? <!-- If there are user-facing changes then we may require documentation to be updated before approving the PR. --> <!-- If there are any breaking changes to public APIs, please add the `api change` label. --> No. -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
