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https://issues.apache.org/jira/browse/CALCITE-6461?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17864239#comment-17864239
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Julian Hyde commented on CALCITE-6461:
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Would it be possible to extend one of the existing metadata types? I think that
would be preferable, even if it means a minor change in behavior.
> Metadata provider for determining if columns originate from aggregate
> functions
> -------------------------------------------------------------------------------
>
> Key: CALCITE-6461
> URL: https://issues.apache.org/jira/browse/CALCITE-6461
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Reporter: Stamatis Zampetakis
> Assignee: Stamatis Zampetakis
> Priority: Major
>
> Add a new metadata provider for determining whether a set of columns
> originates from aggregate functions.
> In Apache Hive, we have a use-case where we need to determine if the columns
> in the result of a query originate from aggregate functions. Along with other
> things, it is used for deciding when to materialize common table expressions.
> {code:sql}
> SELECT job, SUM(sal) as total
> FROM emp
> GROUP BY job
> {code}
> For the query above, the new metadata provider should return:
> * false when the input is column 0 (job)
> * true when the input is column 1 (total)
> * false when the input is columns {0,1}
> The proposed metadata provider presents some similarities with
> {{ColumnOrigin}} and {{ExpressionLineage}} but the latter cannot be easily
> extended to provide this information.
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