Fix force_parallel_mode to work as intended.#1287
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avamingli wants to merge 1 commit intoapache:mainfrom
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Fix force_parallel_mode to work as intended.#1287avamingli wants to merge 1 commit intoapache:mainfrom
avamingli wants to merge 1 commit intoapache:mainfrom
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The force_parallel_mode GUC is meant to facilitate testing of parallel query plans, but it currently allows non-parallel plans to win even when force_parallel_mode is enabled. This behavior makes it difficult to debug parallel plans as intended. Correct the behavior for testing purposes. Authored-by: Zhang Mingli avamingli@gmail.com
yjhjstz
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Aug 3, 2025
| Path *cheapest_partial_path; | ||
| cheapest_partial_path = linitial(final_rel->partial_pathlist); | ||
| if (force_parallel_mode == FORCE_PARALLEL_ON) | ||
| final_rel->pathlist = NIL; |
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if partial_pathlist == NIL，should not final_rel->pathlist = NIL; ?
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pathlist can not be empty- this will trigger a 'could not derive a plan for query' failure.
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This PR opened a whole can of worms. Just skimming through, there are a bunch of wrong results. |
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The force_parallel_mode GUC is meant to facilitate testing of parallel query plans, but it currently allows non-parallel plans to win even when force_parallel_mode is enabled.
This behavior makes it difficult to debug parallel plans as intended.
Correct the behavior for testing purposes.
Authored-by: Zhang Mingli avamingli@gmail.com
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
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