[jira] [Commented] (ARROW-12763) [R] Optimize dplyr queries that use head/tail after arrange

["Neal Richardson (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/ARROW-12763?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17421598#comment-17421598 ] 

Neal Richardson commented on ARROW-12763:
-----------------------------------------

See discussion on ARROW-13767. I think this means we should use the top_k node when that is added (ARROW-13973)

> [R] Optimize dplyr queries that use head/tail after arrange
> -----------------------------------------------------------
>
>                 Key: ARROW-12763
>                 URL: https://issues.apache.org/jira/browse/ARROW-12763
>             Project: Apache Arrow
>          Issue Type: Improvement
>          Components: R
>            Reporter: Ian Cook
>            Priority: Major
>
> Use the Arrow C++ function {{partition_nth_indices}} to optimize dplyr queries like this:
> {code:r}
> iris %>%
>   Table$create() %>% 
>   arrange(desc(Sepal.Length)) %>%
>   head(10) %>%
>   collect()
> {code}
> This query sorts the full table even though it doesn't need to. It could use {{partition_nth_indices}} to find the rows containing the top 10 values of {{Sepal.Length}} and only collect and sort those 10 rows.
> Test to see if this improves performance in practice on larger data.



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