Re: FlinkSQL源码分段优化中，物理计划转换为ExecNodeGraph的时候，SameRelObjectShuttle、SubplanReuseShuttle一拆一合目的是啥

Wed, 24 Nov 2021 18:43:57 -0800 

Hi！

这是因为我们有配置关闭 subplan reuse 和 source reuse，因此需要先把 plan 拆开，然后再判断是否允许
reuse，如果允许才能合并。

岳晗 <yuehan...@qq.com.invalid> 于2021年11月24日周三 下午3:55写道：

> Hi，
>
>
> 请问下FlinkSQL物理计划转换为ExecNodeGraph的时候，拿到optimizedRelNodes后，
>
>
> 首先执行：SameRelObjectShuttle Rewrite same rel object to different rel objects.
> e.g.
> &nbsp; &nbsp; &nbsp; Join&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Join
> &nbsp; &nbsp; &nbsp;/&nbsp; &nbsp; \&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;/&nbsp; &nbsp; \
> &nbsp;Filter1 Filter2&nbsp; &nbsp; &nbsp;=&gt;&nbsp; &nbsp; &nbsp;Filter1
> Filter2
> &nbsp; &nbsp; &nbsp;\&nbsp; &nbsp;/&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;|&nbsp; &nbsp; &nbsp; |
> &nbsp; &nbsp; &nbsp; Scan&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; Scan1&nbsp; &nbsp; Scan2
>
>
>
> 然后执行：SubplanReuseShuttle
> &nbsp; &nbsp; &nbsp; &nbsp;Join&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Join
> &nbsp; &nbsp; &nbsp;/&nbsp; &nbsp; &nbsp; \&nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; /&nbsp; &nbsp; &nbsp; \
> &nbsp;Filter1&nbsp; Filter2&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> Filter1&nbsp; Filter2
> &nbsp; &nbsp; |&nbsp; &nbsp; &nbsp; &nbsp; |&nbsp; &nbsp; &nbsp; &nbsp;
> =&gt;&nbsp; &nbsp; &nbsp; &nbsp;\&nbsp; &nbsp; &nbsp;/
> &nbsp;Project1 Project2&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Project1
> &nbsp; &nbsp; |&nbsp; &nbsp; &nbsp; &nbsp; |&nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; |
> &nbsp; Scan1&nbsp; &nbsp; Scan2&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
> &nbsp;Scan1
>
> val shuttle = new SameRelObjectShuttle()
> val relsWithoutSameObj = optimizedRelNodes.map(_.accept(shuttle))
> // reuse subplan
> val reusedPlan = SubplanReuser.reuseDuplicatedSubplan(relsWithoutSameObj,
> config)
> // convert FlinkPhysicalRel DAG to ExecNodeGraph
> val generator = new ExecNodeGraphGenerator()
> 目的是啥，谢谢回复。

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