You are viewing a plain text version of this content. The canonical link for it is here.
Posted to github@arrow.apache.org by GitBox <gi...@apache.org> on 2020/09/22 15:59:12 UTC
[GitHub] [arrow] nealrichardson commented on a change in pull request #8122: ARROW-9557: [R] Iterating over parquet columns is slow in R
nealrichardson commented on a change in pull request #8122:
URL: https://github.com/apache/arrow/pull/8122#discussion_r492850251
##########
File path: r/R/parquet.R
##########
@@ -409,10 +420,20 @@ ParquetFileWriter$create <- function(schema,
#'
#' @section Methods:
#'
-#' - `$ReadTable(col_select)`: get an `arrow::Table` from the file, possibly
-#' with columns filtered by a character vector of column names or a
-#' `tidyselect` specification.
+#' - `$ReadTable(column_indices)`: get an `arrow::Table` from the file. The optional
+#' `column_indices=` argument is a 0-based integer vector indicating which columns to retain.
+#' - `$ReadRowGroup(i, column_indices)`: get an `arrow::Table` by reading the `i`th row group.
Review comment:
Is `i` also 0-based?
##########
File path: r/R/parquet.R
##########
@@ -409,10 +420,20 @@ ParquetFileWriter$create <- function(schema,
#'
#' @section Methods:
#'
-#' - `$ReadTable(col_select)`: get an `arrow::Table` from the file, possibly
-#' with columns filtered by a character vector of column names or a
-#' `tidyselect` specification.
+#' - `$ReadTable(column_indices)`: get an `arrow::Table` from the file. The optional
+#' `column_indices=` argument is a 0-based integer vector indicating which columns to retain.
+#' - `$ReadRowGroup(i, column_indices)`: get an `arrow::Table` by reading the `i`th row group.
+#' The optional `column_indices=` argument is a 0-based integer vector indicating which columns to retain.
+#' - `$ReadRowGroups(row_groups, column_indices)`: get an `arrow::Table` by reading several row groups.
Review comment:
are `row_groups` also integers? 0-based?
----------------------------------------------------------------
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.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org