[jira] [Issue Comment Deleted] (CALCITE-3952) Improve SortRemoveRule to remove Sort based on rowcount

["Jin Xing (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CALCITE-3952?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jin Xing updated CALCITE-3952:
------------------------------
    Comment: was deleted

(was: Given a rel which emit at most 1 row (RelMetadataQuery.getRowCount(rel) <=1), besides the optimization on Sort, seems we can also optimize other operators like Aggregate.)

> Improve SortRemoveRule to remove Sort based on rowcount
> -------------------------------------------------------
>
>                 Key: CALCITE-3952
>                 URL: https://issues.apache.org/jira/browse/CALCITE-3952
>             Project: Calcite
>          Issue Type: Improvement
>          Components: core
>            Reporter: Vineet Garg
>            Assignee: Vineet Garg
>            Priority: Major
>
> If a query is guaranteed to produce maximum one row it is safe to remove Sort (along with limit). 
> Example:
> {code:sql}
> select count(*) cs from store_sales where ss_ext_sales_price > 100.00 order by cs limit 100
> {code}
> Although logically equivalent this can greatly benefit physical plans by removing extra operator and avoiding unnecessary data transfer.



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