gabotechs opened a new pull request, #19761: URL: https://github.com/apache/datafusion/pull/19761
## 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. --> - Closes #. ## Rationale for this change This is a PR from a batch of PRs that attempt to improve performance in hash joins: - https://github.com/apache/datafusion/pull/19759 - https://github.com/apache/datafusion/pull/19760 - This PR It adds the new `BufferExec` node at the top of the probe side of hash joins so that some work is eagerly performed before the build side of the hash join is completely finished. <!-- 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. --> ## 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. --> Adds a new `HashJoinBuffering` physical optimizer rule that will idempotently place `BufferExec` nodes on the probe side of has joins: ``` ┌───────────────────┐ │ HashJoinExec │ └─────▲────────▲────┘ ┌───────┘ └─────────┐ │ │ ┌────────────────┐ ┌─────────────────┐ │ Build side │ + │ BufferExec │ └────────────────┘ └────────▲────────┘ │ ┌────────┴────────┐ │ Probe side │ └─────────────────┘ ``` ## 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)? --> yes, by existing tests ## Are there any user-facing changes? yes, users will see a new `BufferExec` being placed at top of the probe side of each hash join. (Still unsure about whether de default mode should be enabled) <!-- 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. --> -- 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]
