wjones127 commented on a change in pull request #11894:
URL: https://github.com/apache/arrow/pull/11894#discussion_r773258073
##########
File path: r/R/dataset-scan.R
##########
@@ -185,17 +183,29 @@ ScanTask <- R6Class("ScanTask",
#' `data.frame`? Default `TRUE`
#' @export
map_batches <- function(X, FUN, ..., .data.frame = TRUE) {
- if (.data.frame) {
- lapply <- map_dfr
- }
- scanner <- Scanner$create(ensure_group_vars(X))
+ # TODO: possibly refactor do_exec_plan to return a RecordBatchReader
+ plan <- ExecPlan$create()
+ final_node <- plan$Build(X)
+ reader <- plan$Run(final_node)
FUN <- as_mapper(FUN)
- lapply(scanner$ScanBatches(), function(batch) {
- # TODO: wrap batch in arrow_dplyr_query with X$selected_columns,
- # X$temp_columns, and X$group_by_vars
- # if X is arrow_dplyr_query, if some other arg (.dplyr?) == TRUE
- FUN(batch, ...)
- })
+
+ # TODO: wrap batch in arrow_dplyr_query with X$selected_columns,
+ # X$temp_columns, and X$group_by_vars
+ # if X is arrow_dplyr_query, if some other arg (.dplyr?) == TRUE
+ batch <- reader$read_next_batch()
+ res <- list()
Review comment:
I wasn't aware that's how lists work. Thank you for the explanation! The
difference in memory allocated is particularly surprising.
I'll switch this over.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
