zanmato1984 commented on code in PR #756:
URL: https://github.com/apache/arrow-site/pull/756#discussion_r2791122008
##########
_posts/2026-02-10-arrow-anniversary.md:
##########
@@ -0,0 +1,168 @@
+---
+layout: post
+title: "Apache Arrow is 10 years old 🎉"
+date: "2026-02-09 00:00:00"
+author: pmc
+categories: [arrow]
+---
+<!--
+{% 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 project was officially established and had its
+[first git
commit](https://github.com/apache/arrow/commit/d5aa7c46692474376a3c31704cfc4783c86338f2)
+on February 5th 2016, and we are therefore enthusiastic to announce its 10-year
+anniversary!
+
+Looking back over these 10 years, the project has developed in many unforeseen
+ways and we believe to have delivered on our objective of providing agnostic,
+efficient, durable standards for the exchange of columnar data.
+
+## Apache Arrow 0.1.0
+
+The first Arrow release, numbered 0.1.0, was tagged on October 7th 2016. It
already
+featured the main data types that are still the bread-and-butter of most Arrow
datasets,
+as evidenced in this [Flatbuffers
declaration](https://github.com/apache/arrow/blob/e7080ef9f1bd91505996edd4e4b7643cc54f6b5f/format/Message.fbs#L96-L115):
+
+```flatbuffers
+
+/// ----------------------------------------------------------------------
+/// Top-level Type value, enabling extensible type-specific metadata. We can
+/// add new logical types to Type without breaking backwards compatibility
+
+union Type {
+ Null,
+ Int,
+ FloatingPoint,
+ Binary,
+ Utf8,
+ Bool,
+ Decimal,
+ Date,
+ Time,
+ Timestamp,
+ Interval,
+ List,
+ Struct_,
+ Union
+}
+```
+
+The [release
announcement](https://lists.apache.org/thread/6ow4r2kq1qw1rxp36nql8gokgoczozgw)
+made the bold claim that **"the metadata and physical data representation
should
+be fairly stable as we have spent time finalizing the details"**. Does that
promise
+hold? The short answer is: yes, almost! But let us analyse that in a bit more
detail:
+
+* the [Columnar format](https://arrow.apache.org/docs/format/Columnar.html),
for
+ the most part, has only seen additions of new datatypes since 2016.
+ **One single breaking change** occurred: Union types cannot have a
+ top-level validity bitmap anymore.
+
+* the [IPC
format](https://arrow.apache.org/docs/format/Columnar.html#serialization-and-interprocess-communication-ipc)
+ has seen several minor evolutions of its framing and metadata format; these
+ evolutions are encoded in the `MetadataVersion` field which ensures that new
+ readers can read data produced by old writers. The single breaking change is
+ related to the same Union validity change mentioned above.
+
+## First cross-language integration tests
+
+Arrow 0.1.0 had two implementations: C++ and Java, with bindings of the former
+to Python. There were also no integration tests to speak of, that is, no
automated
+assessment that the two implementations were in sync (what could go wrong?).
+
+Integration tests had to wait for [November
2016](https://issues.apache.org/jira/browse/ARROW-372)
+to be designed, and the first [automated CI
run](https://github.com/apache/arrow/commit/45ed7e7a36fb2a69de468c41132b6b3bbd270c92)
+probably occurred in December of the same year. Its results cannot be fetched
anymore,
+so we can only assume the tests passed successfully. 🙂
+
+From that moment, integration tests have grown to follow additions to the
Arrow format,
+while ensuring that older data can still be read successfully. For example,
the
+integration tests that are routinely checked against multiple implementations
of
+Arrow have data files [generated in 2019 by Arrow
0.14.1](https://github.com/apache/arrow-testing/tree/master/data/arrow-ipc-stream/integration/0.14.1).
+
+## The lost Union validity bitmap
Review Comment:
I as a reader feel this part interesting. And I take this as a callback to
the previously mentioning words. But I think it might be better to highlight
the rationale of this change in a short sentence.
--
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: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
