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<!-- 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 apache#123` indicates that this PR will close issue apache#123. --> - Closes #. <!-- 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. --> This PR fixes memory reservation starvation in sort-merge when multiple sort partitions share a GreedyMemoryPool. When multiple `ExternalSorter` instances run concurrently and share a single memory pool, the merge phase starves: 1. Each partition pre-reserves sort_spill_reservation_bytes via merge_reservation 2. When entering the merge phase, new_empty() was used to create a new reservation starting at 0 bytes, while the pre-reserved bytes sat idle in ExternalSorter.merge_reservation 3. Those freed bytes were immediately consumed by other partitions racing for memory 4. The merge could no longer allocate memory from the pool → OOM / starvation <!-- 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. --> <!-- 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)? --> ~~I can't find a deterministic way to reproduce the bug, but it occurs in our production.~~ Add an end-to-end test to verify the fix <!-- 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. -->
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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The cherry-picked commit from branch-51 used `get_reserved_byte_for_record_batch_size` (1 param), but branch-52 has `get_reserved_bytes_for_record_batch_size` (2 params). Update the call site to use the branch-52 function signature. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
zhuqi-lucas
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Mar 23, 2026
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