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https://issues.apache.org/jira/browse/CALCITE-4677?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17376013#comment-17376013
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Julian Hyde commented on CALCITE-4677:
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[[email protected]], Thanks for the examples. Your description still
contains lot of details about the workings of the planner, and I think the
problem could be described so that people don't need to read those details.
(Why is this important? Because as you have currently described it, only one or
two people in the world will ever understand the bug that you have encountered.
For example, I wrote the planner, but I don't have the necessary two hours to
read the code and understand the bug. But many people might be running into
this bug, or use the functionality that you are planning to provide.)
> Different physical conventions conversion on new physical node producing
> -------------------------------------------------------------------------
>
> Key: CALCITE-4677
> URL: https://issues.apache.org/jira/browse/CALCITE-4677
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.28.0
> Reporter: ZiLin Chen
> Priority: Major
> Labels: pull-request-available
> Time Spent: 20m
> Remaining Estimate: 0h
>
> Whenever new physical nodes are on produce, we need to fire rules in case of
> different physical conventions conversion.
> DeriveTrait Task deal with this case, while some physical node maybe missing.
>
> There 3 rules, but in TopDownRuleDriver rule 3 can not be applied.
> 1. LogicalSortToTopNRuleLogicalSortToTopNRule
> 2. LogicalSortToLimitMemSortRule
> 3. TopNToSomeRelNodeRule (Need Match Physical Convention Node like TopN)
>
> LogicalAggreate -> 1. RelSet1
> - LogicalSort -> 2. RelSet2 fires LogicalSortToTopNRule and
> LogicalSortToLimitMemSortRule
> - OtherNode -> 3. RelSet3
>
> ApplyRuleTask LogicalSortToLimitMemSortRule is already scheduled.
> ApplyRuleTask LogicalSortToTopNRule still on the stack.
>
> when RelSet3 on Merge (Merge with other RelSets), then RelSet2
> clearProcessed(): subset.resetTaskState() and then RelSet1 clearProcessed():
> subset.resetTaskState()
> because RelSet1 is root so OptimizeGroup will be scheduled again
>
> Now the task stack
> Task Stack:
> Task about RelSet1
> Task about RelSet2 ApplyRuleTask LogicalSortToTopNRule
> Task about RelSet3
> Task about RelSet1 root schedule again
> Task about RelSet2
> Task about RelSet3 (current task)
>
> next
> Task Stack:
> Task about RelSet1
> Task about RelSet2
> Task about RelSet3
> Task about RelSet1
> Task about RelSet2 RelSubSet setOptimized so taskState -> Completed. rels on
> RelSet (LogicalSort and LimitMemSort)
>
> next...
> Task Stack:
> Task about RelSet1
> Task about RelSet2 ApplyRuleTask LogicalSortToTopNRule.
> Here we found when TopN is on produce, every RelSubSet can not fire
> OptimizeInputTask. so TopNToSomeRelNodeRule can not fire
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