2.0.0 release blog post (#79)
Co-authored-by: David Li <li.davidm96@gmail.com>
Co-authored-by: liyafan82 <liya.fan03@gmail.com>
Co-authored-by: Joris Van den Bossche <jorisvandenbossche@gmail.com>
Co-authored-by: Kenta Murata <mrkn@users.noreply.github.com>
Co-authored-by: Bryan Cutler <cutlerb@gmail.com>
Co-authored-by: Eric Erhardt <eric.erhardt@microsoft.com>
Co-authored-by: emkornfield <emkornfield@gmail.com>
Co-authored-by: Paul Taylor <paul.e.taylor@me.com>
Co-authored-by: Benjamin Kietzman <bengilgit@gmail.com>
Co-authored-by: Wes McKinney <wesm@apache.org>
diff --git a/_posts/2020-10-15-2.0.0-release.md b/_posts/2020-10-15-2.0.0-release.md
new file mode 100644
index 0000000..7dcb93e
--- /dev/null
+++ b/_posts/2020-10-15-2.0.0-release.md
@@ -0,0 +1,189 @@
+---
+layout: post
+title: "Apache Arrow 2.0.0 Release"
+date: "2020-10-22 00:00:00 -0600"
+author: pmc
+categories: [release]
+---
+<!--
+{% comment %}
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements. See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to you under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License. You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+{% endcomment %}
+-->
+
+The Apache Arrow team is pleased to announce the 2.0.0 release. This covers
+over 3 months of development work and includes [**511 resolved issues**][1]
+from [**81 distinct contributors**][2]. See the Install Page to learn how to
+get the libraries for your platform.
+
+The release notes below are not exhaustive and only expose selected highlights
+of the release. Many other bugfixes and improvements have been made: we refer
+you to the [complete changelog][3].
+
+## Community
+
+Since the 1.0.0 release, [Jorge Leitão][5] has been added as a committer. Thank
+you for your contributions!
+
+## Columnar Format
+
+As this is the first major release since 1.0.0, we remind everyone that we have
+moved to a "split" versioning system where the Library version (which is now
+2.0.0) will now evolve separate from the Format version (which is still
+1.0.0). Major releases of the libraries may contain non-backward-compatible API
+changes, but they will not contain any incompatible format changes. See the
+[Versioning and Stability][6] page in the documentation for more.
+
+The columnar format metadata has been updated to permit 256-bit decimal values
+in addition to 128-bit decimals. This change is backward and forward
+compatible.
+
+## Arrow Flight RPC notes
+
+For Arrow Flight, 2.0.0 mostly brings bugfixes. In Java, some memory leaks in
+`FlightStream` and `DoPut` have been addressed. In C++ and Python, a deadlock
+has been fixed in an edge case. Additionally, when supported by gRPC, TLS
+verification can be disabled.
+
+## C++ notes
+
+Parquet reading now fully supports round trip of arbitrarily nested data,
+including extension types with a nested storage type. In the process, several
+bugs in writing nested data and FixedSizeList were fixed. If writing data with
+these type we recommend upgrading to this release and validating old data as
+there is potential data loss.
+
+Datasets can now be written with partitions, including these features:
+
+* Writing to Parquet, including control over accumulation of statistics for
+ individual columns.
+* Writing to IPC/Feather, including body buffer compression.
+* Basenames of written files can be specified with a string template, allowing
+ non-colliding writes into the same partitioned dataset.
+
+Other notable features in the release include
+
+* Compute kernels for standard deviation, variance, and mode
+* Improvements to S3 support, including automatic region detection
+* CSV reading now parses Date type and creating Dictionary types
+
+## C# notes
+
+The .NET package has added a number of new features this release.
+
+Full support for `Struct` types.
+
+Synchronous write APIs for `ArrowStreamWriter` and `ArrowFileWriter`. These are
+complimentary to the existing async write APIs, and can be used in situations
+where the async APIs can't be used.
+
+The ability to use `DateTime` instances with `Date32Array` and `Date64Array`.
+
+## Java notes
+
+The Java package has supported a number of new features. Users can validate
+vectors in a wider range of aspects, if they are willing to take more time. In
+dictionary encoding, dictionary indices can be expressed as unsigned integers.
+A framework for data compression has been setup for IPC.
+
+The calculation for vector capacity has been simplified, so users should
+experience notable performance improvements for various 'setSafe' methods.
+
+Bugs for JDBC adapters, sort algorithms, and ComplexCopier have been resolved
+to make them more usable.
+
+## JavaScript notes
+
+Upgrades Arrow's build to use TypeScript 3.9, fixing generated `.d.ts` typings.
+
+## Python notes
+
+Parquet reading now supports round trip of arbitrarily nested data. Several bug
+fixes for writing nested data and FixedSizeList. If writing data with these
+type we recommend validating old data (there is potential some data loss) and
+upgrade to 2.0.
+
+Extension types with a nested storage type now round trip through Parquet.
+
+The `pyarrow.filesystem` submodule is deprecated in favor of new filesystem
+implementations in `pyarrow.fs`.
+
+The custom serialization functionality (`pyarrow.serialize()`,
+`pyarrow.deserialize()`, etc) is deprecated. Those functions provided a
+Python-specific (not cross-language) serialization format which were not
+compatible with the standardized Arrow (IPC) serialization format. For
+arbitrary objects, you can use the standard library ``pickle`` functionality
+instead. For pyarrow objects, you can use the IPC serialization format through
+the ``pyarrow.ipc`` module, as explained above.
+
+The `pyarrow.compute` module now has a complete coverage of the available C++
+compute kernels in the python API. Several new kernels have been added.
+
+The `pyarrow.dataset` module was further improved. In addition to reading, it
+is now also possible to write partitioned datasets (with `write_dataset()`).
+
+The Arrow <-> Python conversion code was refactored, fixing several bugs and
+corner cases.
+
+Conversion of an array of `pyarrow.MapType` to Pandas has been added.
+
+Conversion of timezone aware datetimes to and/from pyarrow arrays including
+pandas now round-trip preserving timezone. To use the old behavior (e.g. for
+spark) set the environment variable PYARROW_IGNORE_TIMEZONE to a truthy value
+(i.e. `PYARROW_IGNORE_TIMEZONE=1`)
+
+## R notes
+
+Highlights of the R release include
+
+* Writing multi-file datasets with partitioning to Parquet or Feather
+* Reading and writing directly to AWS S3, both individual files and multi-file
+ datasets
+* Bindings for Flight which use reticulate
+
+In addition, the R package benefits from the various improvements in the C++
+library listed above, including the ability to read and write Parquet files
+with nested struct and list types.
+
+For more on what’s in the 2.0.0 R package, see the [R changelog][4].
+
+## Ruby and C GLib notes
+
+### Ruby
+
+In Ruby binding, `Arrow::Table#save` uses the number of rows as the
+`chunk_size` parameter by default when the table is saved in a Parquet file.
+
+### C GLib
+
+The GLib binding newly supports `GArrowStringDictionaryArrayBuilder` and
+`GArrowBinaryDictionaryArrayBuilder`.
+
+Moreover the GLib binding supports new accessors of `GArrowListArray` and
+`GArrowLargeListArray`. They are `get_values`, `get_value_offset`,
+`get_value_length`, and `get_value_offsets`.
+
+## Rust notes
+
+Due to the high volume of activity in the Rust subproject in this release,
+we're writing a separate blog post dedicated to those changes.
+
+[1]: https://issues.apache.org/jira/issues/?jql=project%20%3D%20ARROW%20AND%20status%20%3D%20Resolved%20AND%20fixVersion%20%3D%202.0.0
+[2]: {{ site.baseurl }}/release/2.0.0.html#contributors
+[3]: {{ site.baseurl }}/release/2.0.0.html
+[4]: {{ site.baseurl }}/docs/r/news/
+[5]: https://github.com/jorgecarleitao
+[6]: http://arrow.apache.org/docs/format/Versioning.html
\ No newline at end of file
