Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/src/arrow/r/man/map_batches.Rd b/src/arrow/r/man/map_batches.Rd
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index 000000000..08e7b86c0
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+++ b/src/arrow/r/man/map_batches.Rd
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+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/dataset-scan.R
+\name{map_batches}
+\alias{map_batches}
+\title{Apply a function to a stream of RecordBatches}
+\usage{
+map_batches(X, FUN, ..., .data.frame = TRUE)
+}
+\arguments{
+\item{X}{A \code{Dataset} or \code{arrow_dplyr_query} object, as returned by the
+\code{dplyr} methods on \code{Dataset}.}
+
+\item{FUN}{A function or \code{purrr}-style lambda expression to apply to each
+batch}
+
+\item{...}{Additional arguments passed to \code{FUN}}
+
+\item{.data.frame}{logical: collect the resulting chunks into a single
+\code{data.frame}? Default \code{TRUE}}
+}
+\description{
+As an alternative to calling \code{collect()} on a \code{Dataset} query, you can
+use this function to access the stream of \code{RecordBatch}es in the \code{Dataset}.
+This lets you aggregate on each chunk and pull the intermediate results into
+a \code{data.frame} for further aggregation, even if you couldn't fit the whole
+\code{Dataset} result in memory.
+}
+\details{
+This is experimental and not recommended for production use.
+}