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Posted to issues@calcite.apache.org by "Julian Hyde (Jira)" <ji...@apache.org> on 2021/04/11 15:20:00 UTC
[jira] [Commented] (CALCITE-4578) skip HepPlanner#buildFinalPlan
when there's no rule fired in the program
[ https://issues.apache.org/jira/browse/CALCITE-4578?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17318826#comment-17318826 ]
Julian Hyde commented on CALCITE-4578:
--------------------------------------
The subject of this case describes the code change, not the problem you are solving. Please improve it.
> skip HepPlanner#buildFinalPlan when there's no rule fired in the program
> ------------------------------------------------------------------------
>
> Key: CALCITE-4578
> URL: https://issues.apache.org/jira/browse/CALCITE-4578
> Project: Calcite
> Issue Type: Bug
> Components: core
> Reporter: Jiatao Tao
> Assignee: Jiatao Tao
> Priority: Major
> Attachments: image-2021-04-11-17-42-38-595.png
>
>
> Example like that: insert xxx VALUES (1, 'one'), (2, 'two'), (3, 'three')...(10000, 'ten thousand');
> It generates a Union node with 10000 inputs, and the performance is poor, here's the profile:
> !image-2021-04-11-17-42-38-595.png|width=1086,height=240!
> We create a program(HepProgram) to do the union merge, in this case, we only have one union, so the rule is not fired, but it will still build the buildFinalPlan, and AbstractRelNode#explain has performance issue in this case(see the flame graph):
> {code:java}
> public RelNode findBestExp() {
> assert root != null;
> executeProgram(mainProgram);
> // Get rid of everything except what's in the final plan.
> collectGarbage();
> return buildFinalPlan(root);
> }
> {code}
> And the union has large inputs, so the performance is poor(in SetOp#replaceInput, we have to recomputeDigest ), we can skip buildFinalPlan if there's no rule fired.
>
>
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