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https://issues.apache.org/jira/browse/CALCITE-4223?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17191916#comment-17191916
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Chunwei Lei commented on CALCITE-4223:
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Thanks for sharing, [~danny0405]. IMO, one of the inconvenient places is that 
Flink has to implement its own {{RelOptTable}} to get {{Statistic}} due to 
{{RelOptTable}} does not provide a method to get {{Statistic}}. 

> Introducing column statistics to RelOptTable
> --------------------------------------------
>
>                 Key: CALCITE-4223
>                 URL: https://issues.apache.org/jira/browse/CALCITE-4223
>             Project: Calcite
>          Issue Type: Improvement
>            Reporter: Chunwei Lei
>            Assignee: Chunwei Lei
>            Priority: Major
>
> Many systems depend on column statistics to compute more accurate stats, such 
> as NDV, average column size, and so on. It would be nice if Calcite can 
> provide such an interface.
> Column statistics might include NDV, average/max column length, number of 
> nulls, number of trues, number of falses and so on. 
> What do you think?
>  



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