ORCA: Optimize CDatumSortedSet by checking IsSorted before sorting #1543
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Check IsSorted before Sort to reduce O(n log n) to O(n-1) comparisons for pre-sorted IN lists, improving ORCA optimization time.
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Pull request overview
This PR optimizes CDatumSortedSet construction by avoiding an unnecessary sort when the underlying array of datums is already sorted, reducing the common-case complexity for pre-sorted IN lists.
Changes:
- Replace unconditional
Sort(&CUtils::IDatumCmp)on the temporaryIDatumArraywith a precedingIsSorted(&CUtils::IDatumCmp)check. - Add an explanatory comment documenting the complexity difference and motivation (pre-sorted
INlists).
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reshke
approved these changes
Jan 23, 2026
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nice spotted |
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Check IsSorted before Sort to reduce O(n log n) to O(n-1) comparisons for pre-sorted IN lists, improving ORCA optimization time.
Fixes #ISSUE_Number
What does this PR do?
Type of Change
Breaking Changes
Test Plan
make installcheckmake -C src/test installcheck-cbdb-parallelImpact
Performance:
User-facing changes:
Dependencies:
Checklist
Additional Context
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