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https://issues.apache.org/jira/browse/CALCITE-3738?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17016606#comment-17016606
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pengzhiwei edited comment on CALCITE-3738 at 1/16/20 7:12 AM:
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Hi [~julianhyde] and [~hyuan] , Thanks for you attention. I think the SQL is
not fully equivalent to the generated RelNode if we remove the LogicalSort.
Maybe in some usage scenario, the target table cannot guarantee the order of
the input rows. But in some case, the target table really need the ordering.
For example，I want to insert an ordered rows to a message queue which can
guarantee the order of the input rows. With this default optimization,I cannot
do this.
So can we make this optimization as a RelOptRule, the physics engine can
decide use or not use this rule according to the actual situation.
was (Author: pzw2018):
I think the SQL is not fully equivalent to the generated RelNode if we
remove the LogicalSort. Maybe in some usage scenario, the target table cannot
guarantee the order of the input rows. But in some case, the target table
really need the ordering.
For example，I want to insert an ordered rows to a message queue which can
guarantee the order of the input rows. With this default optimization,I cannot
do this.
So can we make this optimization as a RelOptRule, the physics engine can
decide use or not use this rule according to the actual situation.
> Missing LogicalSort for insert statement
> ----------------------------------------
>
> Key: CALCITE-3738
> URL: https://issues.apache.org/jira/browse/CALCITE-3738
> Project: Calcite
> Issue Type: Bug
> Components: core
> Affects Versions: 1.19.0
> Reporter: pengzhiwei
> Assignee: pengzhiwei
> Priority: Major
> Labels: pull-request-available
> Time Spent: 1.5h
> Remaining Estimate: 0h
>
> The following sql statement generates a wrong logical plan which missing the
> LogicalSort :
> {code:java}
> insert into t select id*10,name from users order by name;{code}
> the plan is :
> {code:java}
> LogicalTableModify(table=[[t]], operation=[INSERT], flattened=[false])
> LogicalProject(id=[*($0, 10)], name=[$1])
> LogicalTableScan(table=[[users]])
> {code}
> This issue is introduced by the issue
> https://issues.apache.org/jira/browse/CALCITE-2978
> which removes the sort by in sub-query.However the query in insert statement
> is not a sub-query.
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