[GitHub] [arrow] nealrichardson commented on a diff in pull request #13005: ARROW-16276: [R] Arrow 8.0 News

[GitBox <gi...@apache.org>]

nealrichardson commented on code in PR #13005:
URL: https://github.com/apache/arrow/pull/13005#discussion_r862955688


##########
r/NEWS.md:
##########
@@ -19,19 +19,123 @@
 
 # arrow 7.0.0.9000
 
-* `read_csv_arrow()`'s readr-style type `T` is now mapped to `timestamp(unit = "ns")` instead of `timestamp(unit = "s")`.
-* `lubridate`:
-  * component extraction functions: `tz()` (timezone), `semester()` (semester), `dst()` (daylight savings time indicator), `date()` (extract date), `epiyear()` (epiyear), improvements to `month()`, which now works with integer inputs.
-  * Added `make_date()` & `make_datetime()` + `ISOdatetime()` & `ISOdate()` to create date-times from numeric representations. 
-  * Added `decimal_date()` and `date_decimal()`
-  * Added `make_difftime()` (duration constructor)
-  * Added duration helper functions: `dyears()`, `dmonths()`, `dweeks()`, `ddays()`, `dhours()`, `dminutes()`, `dseconds()`, `dmilliseconds()`, `dmicroseconds()`, `dnanoseconds()`.
-* date-time functionality:
-  * Added `as_date()` and `as_datetime()`
-  * Added `difftime` and `as.difftime()` 
-  * Added `as.Date()` to convert to date
+## Enhancements to dplyr and datasets
+
+* `open_dataset()`:
+  - correctly supports the `skip` argument for skipping header rows in CSV datasets.
+  - can take a list of datasets with differing schemas and attempt to unify the 
+    schemas to produce a `UnionDataset`.
+* Arrow `{dplyr}` queries:
+  - are supported on `RecordBatchReader`. This allows, for example, results from DuckDB
+  to be streamed back into Arrow rather than materialized before continuing the pipeline.
+  - no longer need to materialize the entire result table before writing to a dataset
+    if the query contains contains aggregations or joins.
+  - now supports `dplyr::rename_with()`.
+  - `dplyr::count()` now returns an ungrouped dataframe.
+* `write_dataset()` now has more options for controlling row group and file sizes when
+  writing partitioned datasets, such as `max_open_files`, `max_rows_per_file`, 
+  `min_rows_per_group`, and `max_rows_per_group`.
+* `write_csv_arrow()` can write a `Dataset` or an Arrow dplyr query to a single file.
+  - supports `dplyr::rename_with()`.
+  - `dplyr::count()` returns an ungrouped dataframe.
+* `write_dataset` has more options for controlling row group and file sizes when
+  writing partitioned datasets, such as `max_open_files`, `max_rows_per_file`, 
+  `min_rows_per_group`, and `max_rows_per_group`.
+* `write_csv_arrow` accepts a `Dataset` or an Arrow dplyr query.
+* Joining one or more datasets while `option(use_threads = FALSE)` no longer
+  crashes R. That option is set by default on Windows.
+* `dplyr` joins support the `suffix` argument to handle overlap in column names.
+* Filtering a Parquet dataset with `is.na()` no longer misses any rows.
+* `map_batches()` correctly accepts `Dataset` objects.
+
+## Enhancements to date and time support
+
+* `read_csv_arrow()`'s readr-style type `T` is mapped to `timestamp(unit = "ns")` 
+  instead of `timestamp(unit = "s")`.
+* For Arrow dplyr queries, added additional `{lubridate}` features and fixes:
+  * New component extraction functions: 
+    * `lubridate::tz()` (timezone),
+    * `lubridate::semester()` (semester), 
+    * `lubridate::dst()` (daylight savings time indicator),
+    * `lubridate::date()` (extract date), 
+    * `lubridate::epiyear()` (epiyear),
+  * `lubridate::month()` works with integer inputs.
+  * Added `lubridate::make_date()` & `lubridate::make_datetime()` + 
+    `lubridate::ISOdatetime()` & `lubridate::ISOdate()` to 
+    create date-times from numeric representations. 
+  * Added `lubridate::decimal_date()` and `lubridate::date_decimal()`
+  * Added `lubridate::make_difftime()` (duration constructor)
+  * Added `?lubridate::duration` helper functions, such as `dyears()`, `dhours()`, `dseconds()`.
+  * Added `lubridate::leap_year()`
+  * Added `lubridate::as_date()` and `lubridate::as_datetime()`
+* Also for Arrow dplyr queries, added support for base date and time functions:
+  * Added `base::difftime` and `base::as.difftime()` 
+  * Added `base::as.Date()` to convert to date
+  * Arrow timestamp and date arrays support `base::format()`
+  * `strptime()` returns `NA` instead of erroring in case of format mismatch,
+    just like `base::strptime()`.
+* Timezone operations are now supported on Windows if the 
+  [tzdb package](https://cran.r-project.org/package=tzdb) is also
+* Timezone operations are supported on Windows if the 
+  [tzdb package](https://cran.r-project.org/web/packages/tzdb/index.html) is also
+  installed.
+
+## Extensibility
+
+* Added S3 generic conversion functions such as `as_arrow_array()`
+  and `as_arrow_table()` for main Arrow objects. This includes, Arrow tables,
+  record batches, arrays, chunked arrays, record batch readers, schemas, and
+  data types. This allows other packages to define custom conversions from their
+  types to Arrow objects, including extension arrays.
+* Custom [extension types and arrays](https://arrow.apache.org/docs/format/Columnar.html#extension-types) 
+  can be created and registered, allowing other packages to
+  define their own array types. Extension arrays wrap regular Arrow array types and
+  provide customized behavior and/or storage. See description and an example with
+  `?new_extension_type`.
+* Implemented a generic extension type and as_arrow_array() methods for all objects where     
+  `vctrs::vec_is()` returns TRUE (i.e., any object that can be used as a column in a 
+  `tibble::tibble()`), provided that the underlying `vctrs::vec_data()` can be converted 
+  to an Arrow Array.
+
+## Concatenation Support
+
+Arrow arrays and tables can be easily concatenated:
+
+ * Arrays can be concatenated with `concat_arrays()` or, if zero-copy is desired
+   and chunking is acceptable, using `ChunkedArray$create()`.
+ * ChunkedArrays can be concatenated with `c()`.
+ * RecordBatches and Tables support `cbind()`.
+ * Tables support `rbind()`. `concat_tables()` is also provided to 
+ * Chunked arrays can be concatenated with `c()`.
+ * Record batches and tables support `cbind()`.
+ * Arrow tables support `rbind()`. `concat_tables()` is also provided to 
+   concatenate tables while unifying schemas.
+
+## Other improvements and fixes
+
+* Dictionary arrays support using ALTREP when converting to R factors.
+* Math group generics are implemented for ArrowDatum. This means you can use
+  base functions like `sqrt()`, `log()`, and `exp()` with Arrow arrays and scalars.
+* `read_*` and `write_*` functions support R Connection objects for reading
+  and writing files.
+* Parquet improvements:
+  * Parquet writer supports Duration type columns.
+  * The dataset Parquet reader consumes less memory.
 * `median()` and `quantile()` will warn once about approximate calculations regardless of interactivity.
-* Removed Solaris workarounds, libarrow is now required.
+* `Array$cast()` can cast struct arrays into another struct type with the same field names
+  and structure (or a subset of fields) but different field types.
+* The CSV writer is now much faster when writing string columns.

Review Comment:
   More duplicated lines
   
   ```suggestion
   ```



-- 
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-unsubscribe@arrow.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org