[
https://issues.apache.org/jira/browse/ARROW-13767?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17417826#comment-17417826
]
Jonathan Keane edited comment on ARROW-13767 at 9/27/21, 7:41 PM:
------------------------------------------------------------------
The [dplyr docs say they "do not work with relational
databases"|https://dplyr.tidyverse.org/reference/slice.html#details]
Though, IME, many real-world uses of {{slice()}}, {{slice_head()}},
{{slice_tail()}} happen after an arrange:
{code:r}
library(dplyr)
mtcars %>%
group_by(cyl) %>%
arrange(mpg) %>%
slice_head(n = 2)
{code}
These are better written using `slice_min()`, though there has been some
evolution around that + `top_n()` and the like. I've seen code like the above
(with {{arrange}} + {{slice_head}}) a lot.
was (Author: jonkeane):
The[ dplyr docs say they "do not work with relational
databases"|https://dplyr.tidyverse.org/reference/slice.html#details]
Though, IME, many real-world uses of {{slice()}}, {{slice_head()}},
{{slice_tail()}} happen after an arrange:
{code:r}
library(dplyr)
mtcars %>%
group_by(cyl) %>%
arrange(mpg) %>%
slice_head(n = 2)
{code}
These are better written using `slice_min()`, though there has been some
evolution around that + `top_n()` and the like. I've seen code like the above
(with {{arrange}} + {{slice_head}}) a lot.
> [R] Add Arrow methods slice(), slice_head(), slice_tail()
> ---------------------------------------------------------
>
> Key: ARROW-13767
> URL: https://issues.apache.org/jira/browse/ARROW-13767
> Project: Apache Arrow
> Issue Type: Improvement
> Components: R
> Reporter: Ian Cook
> Priority: Major
> Labels: query-engine
> Fix For: 7.0.0
>
>
> Implement [{{slice()}}, {{slice_head()}}, and
> {{slice_tail()}}|https://dplyr.tidyverse.org/reference/slice.html] methods
> for {{ArrowTabular}}, {{Dataset}}, and {{arrow_dplyr_query}} objects . I
> believe this should be relatively straightforward, using {{Take()}} to return
> only the specified rows. We already have a {{head()}} method which I believe
> we can reuse for {{slice_head()}}.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
