CALCITE-5647 Use mq.getRowCount(rel) instead of rel.estimateRowCount(mq)#3151
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adamkennedy wants to merge 1 commit intoapache:mainfrom
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CALCITE-5647 Use mq.getRowCount(rel) instead of rel.estimateRowCount(mq)#3151adamkennedy wants to merge 1 commit intoapache:mainfrom
adamkennedy wants to merge 1 commit intoapache:mainfrom
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Could you please add a test to show the difference?
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Hi @adamkennedy, @libenchao , @chunweilei and others. (That PR has the unit test and is rebased on main). |
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Should this PR be closed? |
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Yes, please do. |
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Closed in favor of #3632 |
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This PR corrects a row count call to use the RelMetadataQuery instead of going directly to rel.estimateRowCount.
Using rel.estimateRowCount directly will behave incorrectly when using a cardinality estimator that is implemented entirely in a MetadataHandler class, as it will evade the metadata handler's implementation of getRowCount and fall through to the underlying default method for Values.
This corrects the problem by using mq.getRowCount instead of rel.estimateRowCount. In the default case this results in the same value but in the custom cardinality model case the expected handler is called.