apache · lidavidm · Nov 9, 2025 · Nov 7, 2025
diff --git a/_posts/2025-11-07-adbc-21-release.md b/_posts/2025-11-07-adbc-21-release.md
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+---
+layout: post
+title: "Apache Arrow ADBC 21 (Libraries) Release"
+date: "2025-11-07 00:00:00"
+author: pmc
+categories: [release]
+---
+<!--
+{% comment %}
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+http://www.apache.org/licenses/LICENSE-2.0
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+
+The Apache Arrow team is pleased to announce the version 21 release of
+the Apache Arrow ADBC libraries. This release includes [**30
+resolved issues**][1] from [**23 distinct contributors**][2].
+
+This is a release of the **libraries**, which are at version 21.  The
+[**API specification**][specification] is versioned separately and is at
+version 1.1.0.
+
+The subcomponents are versioned independently:
+
+- C/C++/GLib/Go/Python/Ruby: 1.9.0
+- C#: 0.21.0
+- Java: 0.21.0
+- R: 0.21.0
+- Rust: 0.21.0
+
+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].
+
+## Release Highlights
+
+Language bindings:
+- The driver manager reports better errors when it fails to find a driver ([#3646](https://github.com/apache/arrow-adbc/pull/3646)).
+- The Python driver manager now searches for manifests in the proper location when inside a Python virtual environment ([#3490](https://github.com/apache/arrow-adbc/pull/3490)).
+- Added convenience methods to the driver manager on top of the standard DBAPI-2.0/PEP249 APIs ([#3539](https://github.com/apache/arrow-adbc/pull/3539)).
+- The signature for `connect` has been simplified, so you can connect without having to repeat the driver name or specify explicit keyword arguments depending on the driver ([#3537](https://github.com/apache/arrow-adbc/pull/3537)).
+- Support for Python 3.9 has been dropped ([#3573](https://github.com/apache/arrow-adbc/pull/3573), [#3663](https://github.com/apache/arrow-adbc/pull/3663)).
+- Support for Python 3.14 (including the free-threading variant) has been added ([#3575](https://github.com/apache/arrow-adbc/pull/3575), [#3620](https://github.com/apache/arrow-adbc/pull/3620), [#3663](https://github.com/apache/arrow-adbc/pull/3663)).
+- The R bindings now support `replace` and `create_append` ingest modes.
+
+Drivers:
+- The Go BigQuery driver now supports service account impersonation ([#3488](https://github.com/apache/arrow-adbc/pull/3488)) and setting a quota project ([#3622](https://github.com/apache/arrow-adbc/pull/3622)).
+- The Go BigQuery driver now returns more detailed type metadata in result sets ([#3604](https://github.com/apache/arrow-adbc/pull/3604)).
+- The C# BigQuery driver allows setting a location ([#3494](https://github.com/apache/arrow-adbc/pull/3494)).
+- The C# Databricks driver adjusted default settings to make small queries faster ([#3489](https://github.com/apache/arrow-adbc/pull/3489)).
+- Memory usage of the C# Databricks driver was improved ([#3652](https://github.com/apache/arrow-adbc/pull/3652), [#3656](https://github.com/apache/arrow-adbc/pull/3656)).
+- All C# HiveServer2-based drivers (Hive, Impala, Spark, Databricks) throw Unauthorized exceptions when appropriate ([#3551](https://github.com/apache/arrow-adbc/pull/3551)).
+- JNI bindings to the C++ driver manager are now released, making it possible to use non-Java drivers from a Java application (in a very limited fashion) ([#3429](https://github.com/apache/arrow-adbc/pull/3429)).  Binary artifacts are available for amd64/arm64 Linux, arm64 macOS, and amd64 Windows.
+- The PostgreSQL driver can now return the schema of any bind parameters in a prepared query ([#3579[(https://github.com/apache/arrow-adbc/pull/3579)]]).
+- The PostgreSQL driver properly batches result sets with large string/binary values now ([#3616](https://github.com/apache/arrow-adbc/pull/3616)).
+- The Snowflake driver now returns float64 for numeric columns when use_high_precision is false and scale is nonzero ([#3295](https://github.com/apache/arrow-adbc/pull/3295)).  (Previously it incorrectly truncated to int64.)
+- Added an option to disable the "vectorized" scanner when ingesting data into Snowflake, which sometimes appeared to cause performance issues ([#3555](https://github.com/apache/arrow-adbc/pull/3555)).
+
+Packaging:
+- Added AlmaLinux 10 ([#3514](https://github.com/apache/arrow-adbc/pull/3514)).
+- Added Debian Trixie ([#3513](https://github.com/apache/arrow-adbc/pull/3513)).
+
+## Contributors
+
+```
+$ git shortlog --perl-regexp --author='^((?!dependabot\[bot\]).*)$' -sn apache-arrow-adbc-20..apache-arrow-adbc-21
+    28	David Li
+     9	Bruce Irschick
+     7	eric-wang-1990
+     6	Curt Hagenlocher
+     5	eitsupi
+     4	msrathore-db
+     3	Bryce Mecum
+     3	Mandukhai Alimaa
+     3	Sutou Kouhei
+     3	davidhcoe
+     2	Anna Lee
+     2	Jason Lin
+     2	Kevin Liu
+     1	Dewey Dunnington
+     1	Ian Cook
+     1	Jacky Hu
+     1	Jade Wang
+     1	Kristin Cowalcijk
+     1	Lucas Valente
+     1	Matthijs Brobbel
+     1	bruceNu1l
+     1	praveentandra
+     1	rnowacoski
+```
+
+## Roadmap
+
+We are starting work on async interfaces and other API enhancements, and
+welcome comments or contributions from anyone interested.  See the initial
+pull requests:
+
+- https://github.com/apache/arrow-adbc/pull/3607
+- https://github.com/apache/arrow-adbc/pull/3623
+
+## Getting Involved
+
+We welcome questions and contributions from all interested.  Issues
+can be filed on [GitHub][4], and questions can be directed to GitHub
+or the [Arrow mailing lists][5].
+
+[1]: https://github.com/apache/arrow-adbc/milestone/25
+[2]: #contributors
+[3]: https://github.com/apache/arrow-adbc/blob/apache-arrow-adbc-21/CHANGELOG.md
+[4]: https://github.com/apache/arrow-adbc/issues
+[5]: {% link community.md %}
+[specification]: https://arrow.apache.org/adbc/21/format/specification.html