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Type:
Improvement
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Resolution: Unresolved
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: None
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Query Optimization
when the mode is PlanCachingMode::AlwaysCache or PlanCachingMode::SometimesCache, there is a special case.
take Classic plan cache for example:
If the winning index's advanced = 0 && works == 1 && isEOF == true, which means we didn't get any data to rank score, all candidates
score is same. the score of the calculation is meaningless.
In this case, if we cache the plan, it will increased memory overhead. when the cached plan stage pick best plan, it will trigger replan. this will increase computing overhead.