Throne3d commented on code in PR #6:
URL: https://github.com/apache/datafusion-site/pull/6#discussion_r1687365607
##########
_posts/2024-07-23-datafusion-40.0.0.md:
##########
@@ -0,0 +1,492 @@
+---
+layout: post
+title: "Apache DataFusion 40.0.0 Released"
+date: "2024-07-21 00:00:00"
+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 %}
+-->
+
+<!-- see https://github.com/apache/datafusion/issues/9602 for details -->
+
+## Introduction
+
+We are proud to announce [DataFusion 40.0.0]. This blog highlights some of the
+many major improvements since we released [DataFusion 34.0.0] and a preview of
+what the community is thinking about in the next 6 months. We are hoping to
make
+more regular blog posts -- if you are interested in helping write them, please
+reach out!
+
+[DataFusion 34.0.0]:
https://datafusion.apache.org/blog/2024/01/19/datafusion-34.0.0/
+[DataFusion 40.0.0]: https://crates.io/crates/datafusion/40.0.0
+
+[Apache DataFusion] is an extensible query engine, written in [Rust], that
+uses [Apache Arrow] as its in-memory format. DataFusion is used by developers
to
+create new, fast data centric systems such as databases, dataframe libraries,
+machine learning and streaming applications. While [DataFusionβs primary design
+goal] is to accelerate the creation of other data centric systems, it has a
+reasonable experience directly out of the box as a [dataframe library] and
+[command line SQL tool].
+
+[DataFusionβs primary design goal]:
https://datafusion.apache.org/user-guide/introduction.html#project-goals
+[dataframe library]: https://datafusion.apache.org/python/
+[command line SQL tool]: https://datafusion.apache.org/user-guide/cli/
+
+[apache datafusion]: https://datafusion.apache.org/
+[apache arrow]: https://arrow.apache.org
+[rust]: https://www.rust-lang.org/
+
+DataFusion's core thesis is that as a community together, we can build much
more
+advanced technology than any of us as individuals or companies could do alone.
+Without DataFusion, highly performant vectorized query engines would remain
+the domain of a few large companies and world-class research institutions.
+With DataFusion, we can all build on top of a shared foundation, and focus on
+what makes our projects unique.
+
+
+# Community Growth π
+
+In the last 6 months, between `34.0.0` and `40.0.0`, our community continues to
+grow in new and exciting ways.
+
+1. DataFusion became a top level Apache Software Foundation project (read the
+ [press release] and [blog post]).
+2. We added several PMC members and new
+ committers [@comphead], [@mustafasrepo], [@ozankabak] joined the PMC,
+ [@jonahgao] and [@lewiszlw] joined as a committer. See the [mailing list]
for
+ more details.
+3. [DataFusion Comet] was [donated] and is nearing its first release.
+4. In the [core DataFusion repo] alone we reviewed and accepted almost 1500
PRs from 182 different
+ committers, created over 1000 issues and closed 781 of them π. This is up
+ almost 50% from our last post (1000 PRs from 124 committers with 650 issues
+ created in our last post) π€―. All changes are listed in the detailed
+ [CHANGELOG].
+5. DataFusion focused meetups happened or are happening in multiple cities
+ around the world: [Austin], [San Francisco], [Hangzhou], [New York], and
+ [Belgrade].
+6. Many new projects started in the [datafusion-contrib] organization,
including
+ [Table Providers], [SQLancer], [Open Variant], [JSON], and [ORC].
+
+[core DataFusion repo]: https://github.com/apache/arrow-datafusion
+[CHANGELOG]:
https://github.com/apache/datafusion/blob/main/datafusion/CHANGELOG.md
+[press release]:
https://news.apache.org/foundation/entry/apache-software-foundation-announces-new-top-level-project-apache-datafusion
+[blog post]: https://datafusion.apache.org/blog/2024/05/07/datafusion-tlp/
+[mailing list]: https://lists.apache.org/list.html?d...@datafusion.apache.org
+[Austin]: https://github.com/apache/datafusion/discussions/8522
+[San Francisco]: https://github.com/apache/datafusion/discussions/10800
+[Hangzhou]: https://www.huodongxing.com/event/5761971909400?td=1965290734055
+[New York]: https://github.com/apache/datafusion/discussions/11213
+[Belgrade]: https://github.com/apache/datafusion/discussions/11431
+[datafusion-contrib]: https://github.com/datafusion-contrib
+[Table Providers]:
https://github.com/datafusion-contrib/datafusion-table-providers
+[SQLancer]: https://github.com/datafusion-contrib/datafusion-sqlancer
+[Open Variant]:
https://github.com/datafusion-contrib/datafusion-functions-variant
+[JSON]: https://github.com/datafusion-contrib/datafusion-functions-json
+[ORC]: https://github.com/datafusion-contrib/datafusion-orc
+
+<!--
+$ git log --pretty=oneline 34.0.0..40.0.0 . | wc -l
+ 1453 (up from 1009)
+
+$ git shortlog -sn 34.0.0..40.0.0 . | wc -l
+ 182 (up from 124)
+
+https://crates.io/crates/datafusion/34.0.0
+DataFusion 34 released Dec 17, 2023
+
+https://crates.io/crates/datafusion/40.0.0
+DataFusion 34 released July 12, 2024
+
+Issues created in this time: 321 open, 781 closed (up from 214 open, 437
closed)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+created%3A2023-12-17..2024-07-12
+
+Issues closed: 911 (up from 517)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+closed%3A2023-12-17..2024-07-12
+
+PRs merged in this time 1490 (up from 908)
+https://github.com/apache/arrow-datafusion/pulls?q=is%3Apr+merged%3A2023-12-17..2024-07-12
+
+-->
+
+
+In addition, DataFusion has been appearing publicly more and more, both online
and offline. Here are some highlights:
+
+1. [Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query
Engine], was presented in [SIGMOD '24], one of the major database conferences
+2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around...] from Andy Pavlo and Mike Stonebraker
+3. ["Why you should keep an eye on Apache DataFusion and its community"]
+4. [Apache DataFusion offline meetup in the Bay Area]
+
+
+[DataFusion Comet]: https://datafusion.apache.org/comet/
+[donated]: https://arrow.apache.org/blog/2024/03/06/comet-donation/
+[SIGMOD '24]: https://2024.sigmod.org/
+
+
+[Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query Engine]:
https://dl.acm.org/doi/10.1145/3626246.3653368
+["What Goes Around Comes Around... And Around...]:
https://db.cs.cmu.edu/papers/2024/whatgoesaround-sigmodrec2024.pdf
+["Why you should keep an eye on Apache DataFusion and its community"]:
https://www.cpard.xyz/posts/datafusion/
+[Apache DataFusion offline meetup in the Bay Area]:
https://www.tisonkun.org/2024/07/15/datafusion-meetup-san-francisco/
+
+
+# Improved Performance π
+
+Performance is a key feature of DataFusion, and the community continues to work
+to keep DataFusion state of the art in this area. One major area DataFusion
+improved is the time it takes to convert a SQL query into a plan that can be
+executed. Planning is now almost 2x faster for TPC-DS and TPC-H queries, and
+over 10x faster for some queries with many columns.
+
+Here is a chart showing the improvement due to the concerted effort of many
+contributors including [@jackwener], [@alamb], [@Lordworms], [@dmitrybugakov],
+[@appletreeisyellow], [@ClSlaid], [@rohitrastogi], [@emgeee],
[@kevinmingtarja],
+and [@peter-toth] over several months (see [ticket] for more details)
+
+<img src="{{ site.baseurl
}}/assets/datafusion-40.0.0/improved-planning-time.png" width="700">
+
+[ticket]: https://github.com/apache/datafusion/issues/9637
+
+DataFusion is now up to 40% faster for queries that `GROUP BY` a single string
+or binary column due to a [specialization for single
+Uft8/LargeUtf8/Binary/LargeBinary]. We are working on improving performance
when
+there are [multiple variable length columns in the `GROUP BY` clause].
+
+[specialization for single Uft8/LargeUtf8/Binary/LargeBinary]:
https://github.com/apache/datafusion/pull/8827
+
+We are also in the final phases of [integrating] the new [Arrow StringView]
+which significantly improves performance for workloads that scan, filter and
+group by variable length string and binary data. We expect the improvement to
be
+especially pronounced for Parquet files due to [upstream work in the parquet
+reader]. Kudos to [@XiangpengHong], [@AriesDevil], [@PsiACE], [@Weijun-H],
+[@a10y], and [@RinChanNOWWW] for driving this project.
+
+[integrating]: https://github.com/apache/datafusion/issues/10918
+[Arrow StringView]:
https://docs.rs/arrow/latest/arrow/array/struct.GenericByteViewArray.html
+[multiple variable length columns in the `GROUP BY` clause]:
https://github.com/apache/datafusion/issues/9403
+[upstream work in the parquet reader]:
https://github.com/apache/arrow-rs/issues/5530
+
+# Improved Quality π
+
+DataFusion continues to improve overall in quality. In addition to ongoing bug
+fixes, one of the most exciting improvements is the addition of a new
[SQLancer]
+based [DataFusion Fuzzing] suite thanks to [@2010YOUY01] that has already found
+several bugs and thanks to [@jonahgao], [@tshauck], [@xinlifoobar],
+[@LorrensP-2158466] for fixing them so fast.
+
+[DataFusion Fuzzing]: https://github.com/apache/datafusion/issues/11030
+
+
+## Improved Documentation π
+
+We continue to improve the documentation to make it easier to get started
using DataFusion with
+the [Library Users Guide], [API documentation], and [Examples].
+
+Some notable new examples include:
+* [sql_analysis.rs] to analyse SQL queries with DataFusion structures (thanks
[@LorrensP-2158466])
+* [function_factory.rs] to create custom functions via SQL (thanks
[@milenkovicm])
+* [plan_to_sql.rs] to generate SQL from DataFusion Expr and LogicalPlan
(thanks [@edmondop])
+* [parquet_index.rs] and [advanced_parquet_index.rs] for parquet indexing,
described more below (thanks [@alamb])
+
+[Library Users Guide]:
https://datafusion.apache.org/library-user-guide/index.html
+[API documentation]: https://docs.rs/datafusion/latest/datafusion/index.html
+[Examples]: https://github.com/apache/datafusion/tree/main/datafusion-examples
+[sql_analysis.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/sql_analysis.rs
+[plan_to_sql.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+# New Features β¨
+
+There are too many new features in the last 6 months to list them all, but here
+are some highlights:
+
+## SQL
+* Support for`UNNEST` (thanks [@duongcongtoai], [@JasonLi-cn] and
[@jayzhan211])
Review Comment:
```suggestion
* Support for `UNNEST` (thanks [@duongcongtoai], [@JasonLi-cn] and
[@jayzhan211])
```
##########
_posts/2024-07-23-datafusion-40.0.0.md:
##########
@@ -0,0 +1,492 @@
+---
+layout: post
+title: "Apache DataFusion 40.0.0 Released"
+date: "2024-07-21 00:00:00"
+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 %}
+-->
+
+<!-- see https://github.com/apache/datafusion/issues/9602 for details -->
+
+## Introduction
+
+We are proud to announce [DataFusion 40.0.0]. This blog highlights some of the
+many major improvements since we released [DataFusion 34.0.0] and a preview of
+what the community is thinking about in the next 6 months. We are hoping to
make
+more regular blog posts -- if you are interested in helping write them, please
+reach out!
+
+[DataFusion 34.0.0]:
https://datafusion.apache.org/blog/2024/01/19/datafusion-34.0.0/
+[DataFusion 40.0.0]: https://crates.io/crates/datafusion/40.0.0
+
+[Apache DataFusion] is an extensible query engine, written in [Rust], that
+uses [Apache Arrow] as its in-memory format. DataFusion is used by developers
to
+create new, fast data centric systems such as databases, dataframe libraries,
+machine learning and streaming applications. While [DataFusionβs primary design
+goal] is to accelerate the creation of other data centric systems, it has a
+reasonable experience directly out of the box as a [dataframe library] and
+[command line SQL tool].
+
+[DataFusionβs primary design goal]:
https://datafusion.apache.org/user-guide/introduction.html#project-goals
+[dataframe library]: https://datafusion.apache.org/python/
+[command line SQL tool]: https://datafusion.apache.org/user-guide/cli/
+
+[apache datafusion]: https://datafusion.apache.org/
+[apache arrow]: https://arrow.apache.org
+[rust]: https://www.rust-lang.org/
+
+DataFusion's core thesis is that as a community together, we can build much
more
+advanced technology than any of us as individuals or companies could do alone.
+Without DataFusion, highly performant vectorized query engines would remain
+the domain of a few large companies and world-class research institutions.
+With DataFusion, we can all build on top of a shared foundation, and focus on
+what makes our projects unique.
+
+
+# Community Growth π
+
+In the last 6 months, between `34.0.0` and `40.0.0`, our community continues to
+grow in new and exciting ways.
+
+1. DataFusion became a top level Apache Software Foundation project (read the
+ [press release] and [blog post]).
+2. We added several PMC members and new
+ committers [@comphead], [@mustafasrepo], [@ozankabak] joined the PMC,
+ [@jonahgao] and [@lewiszlw] joined as a committer. See the [mailing list]
for
+ more details.
+3. [DataFusion Comet] was [donated] and is nearing its first release.
+4. In the [core DataFusion repo] alone we reviewed and accepted almost 1500
PRs from 182 different
+ committers, created over 1000 issues and closed 781 of them π. This is up
+ almost 50% from our last post (1000 PRs from 124 committers with 650 issues
+ created in our last post) π€―. All changes are listed in the detailed
+ [CHANGELOG].
+5. DataFusion focused meetups happened or are happening in multiple cities
+ around the world: [Austin], [San Francisco], [Hangzhou], [New York], and
+ [Belgrade].
+6. Many new projects started in the [datafusion-contrib] organization,
including
+ [Table Providers], [SQLancer], [Open Variant], [JSON], and [ORC].
+
+[core DataFusion repo]: https://github.com/apache/arrow-datafusion
+[CHANGELOG]:
https://github.com/apache/datafusion/blob/main/datafusion/CHANGELOG.md
+[press release]:
https://news.apache.org/foundation/entry/apache-software-foundation-announces-new-top-level-project-apache-datafusion
+[blog post]: https://datafusion.apache.org/blog/2024/05/07/datafusion-tlp/
+[mailing list]: https://lists.apache.org/list.html?d...@datafusion.apache.org
+[Austin]: https://github.com/apache/datafusion/discussions/8522
+[San Francisco]: https://github.com/apache/datafusion/discussions/10800
+[Hangzhou]: https://www.huodongxing.com/event/5761971909400?td=1965290734055
+[New York]: https://github.com/apache/datafusion/discussions/11213
+[Belgrade]: https://github.com/apache/datafusion/discussions/11431
+[datafusion-contrib]: https://github.com/datafusion-contrib
+[Table Providers]:
https://github.com/datafusion-contrib/datafusion-table-providers
+[SQLancer]: https://github.com/datafusion-contrib/datafusion-sqlancer
+[Open Variant]:
https://github.com/datafusion-contrib/datafusion-functions-variant
+[JSON]: https://github.com/datafusion-contrib/datafusion-functions-json
+[ORC]: https://github.com/datafusion-contrib/datafusion-orc
+
+<!--
+$ git log --pretty=oneline 34.0.0..40.0.0 . | wc -l
+ 1453 (up from 1009)
+
+$ git shortlog -sn 34.0.0..40.0.0 . | wc -l
+ 182 (up from 124)
+
+https://crates.io/crates/datafusion/34.0.0
+DataFusion 34 released Dec 17, 2023
+
+https://crates.io/crates/datafusion/40.0.0
+DataFusion 34 released July 12, 2024
+
+Issues created in this time: 321 open, 781 closed (up from 214 open, 437
closed)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+created%3A2023-12-17..2024-07-12
+
+Issues closed: 911 (up from 517)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+closed%3A2023-12-17..2024-07-12
+
+PRs merged in this time 1490 (up from 908)
+https://github.com/apache/arrow-datafusion/pulls?q=is%3Apr+merged%3A2023-12-17..2024-07-12
+
+-->
+
+
+In addition, DataFusion has been appearing publicly more and more, both online
and offline. Here are some highlights:
+
+1. [Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query
Engine], was presented in [SIGMOD '24], one of the major database conferences
+2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around...] from Andy Pavlo and Mike Stonebraker
+3. ["Why you should keep an eye on Apache DataFusion and its community"]
+4. [Apache DataFusion offline meetup in the Bay Area]
+
+
+[DataFusion Comet]: https://datafusion.apache.org/comet/
+[donated]: https://arrow.apache.org/blog/2024/03/06/comet-donation/
+[SIGMOD '24]: https://2024.sigmod.org/
+
+
+[Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query Engine]:
https://dl.acm.org/doi/10.1145/3626246.3653368
+["What Goes Around Comes Around... And Around...]:
https://db.cs.cmu.edu/papers/2024/whatgoesaround-sigmodrec2024.pdf
Review Comment:
```suggestion
["What Goes Around Comes Around... And Around..."]:
https://db.cs.cmu.edu/papers/2024/whatgoesaround-sigmodrec2024.pdf
```
##########
_posts/2024-07-23-datafusion-40.0.0.md:
##########
@@ -0,0 +1,492 @@
+---
+layout: post
+title: "Apache DataFusion 40.0.0 Released"
+date: "2024-07-21 00:00:00"
+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 %}
+-->
+
+<!-- see https://github.com/apache/datafusion/issues/9602 for details -->
+
+## Introduction
+
+We are proud to announce [DataFusion 40.0.0]. This blog highlights some of the
+many major improvements since we released [DataFusion 34.0.0] and a preview of
+what the community is thinking about in the next 6 months. We are hoping to
make
+more regular blog posts -- if you are interested in helping write them, please
+reach out!
+
+[DataFusion 34.0.0]:
https://datafusion.apache.org/blog/2024/01/19/datafusion-34.0.0/
+[DataFusion 40.0.0]: https://crates.io/crates/datafusion/40.0.0
+
+[Apache DataFusion] is an extensible query engine, written in [Rust], that
+uses [Apache Arrow] as its in-memory format. DataFusion is used by developers
to
+create new, fast data centric systems such as databases, dataframe libraries,
+machine learning and streaming applications. While [DataFusionβs primary design
+goal] is to accelerate the creation of other data centric systems, it has a
+reasonable experience directly out of the box as a [dataframe library] and
+[command line SQL tool].
+
+[DataFusionβs primary design goal]:
https://datafusion.apache.org/user-guide/introduction.html#project-goals
+[dataframe library]: https://datafusion.apache.org/python/
+[command line SQL tool]: https://datafusion.apache.org/user-guide/cli/
+
+[apache datafusion]: https://datafusion.apache.org/
+[apache arrow]: https://arrow.apache.org
+[rust]: https://www.rust-lang.org/
+
+DataFusion's core thesis is that as a community together, we can build much
more
+advanced technology than any of us as individuals or companies could do alone.
+Without DataFusion, highly performant vectorized query engines would remain
+the domain of a few large companies and world-class research institutions.
+With DataFusion, we can all build on top of a shared foundation, and focus on
+what makes our projects unique.
+
+
+# Community Growth π
+
+In the last 6 months, between `34.0.0` and `40.0.0`, our community continues to
+grow in new and exciting ways.
+
+1. DataFusion became a top level Apache Software Foundation project (read the
+ [press release] and [blog post]).
+2. We added several PMC members and new
+ committers [@comphead], [@mustafasrepo], [@ozankabak] joined the PMC,
+ [@jonahgao] and [@lewiszlw] joined as a committer. See the [mailing list]
for
+ more details.
+3. [DataFusion Comet] was [donated] and is nearing its first release.
+4. In the [core DataFusion repo] alone we reviewed and accepted almost 1500
PRs from 182 different
+ committers, created over 1000 issues and closed 781 of them π. This is up
+ almost 50% from our last post (1000 PRs from 124 committers with 650 issues
+ created in our last post) π€―. All changes are listed in the detailed
+ [CHANGELOG].
+5. DataFusion focused meetups happened or are happening in multiple cities
+ around the world: [Austin], [San Francisco], [Hangzhou], [New York], and
+ [Belgrade].
+6. Many new projects started in the [datafusion-contrib] organization,
including
+ [Table Providers], [SQLancer], [Open Variant], [JSON], and [ORC].
+
+[core DataFusion repo]: https://github.com/apache/arrow-datafusion
+[CHANGELOG]:
https://github.com/apache/datafusion/blob/main/datafusion/CHANGELOG.md
+[press release]:
https://news.apache.org/foundation/entry/apache-software-foundation-announces-new-top-level-project-apache-datafusion
+[blog post]: https://datafusion.apache.org/blog/2024/05/07/datafusion-tlp/
+[mailing list]: https://lists.apache.org/list.html?d...@datafusion.apache.org
+[Austin]: https://github.com/apache/datafusion/discussions/8522
+[San Francisco]: https://github.com/apache/datafusion/discussions/10800
+[Hangzhou]: https://www.huodongxing.com/event/5761971909400?td=1965290734055
+[New York]: https://github.com/apache/datafusion/discussions/11213
+[Belgrade]: https://github.com/apache/datafusion/discussions/11431
+[datafusion-contrib]: https://github.com/datafusion-contrib
+[Table Providers]:
https://github.com/datafusion-contrib/datafusion-table-providers
+[SQLancer]: https://github.com/datafusion-contrib/datafusion-sqlancer
+[Open Variant]:
https://github.com/datafusion-contrib/datafusion-functions-variant
+[JSON]: https://github.com/datafusion-contrib/datafusion-functions-json
+[ORC]: https://github.com/datafusion-contrib/datafusion-orc
+
+<!--
+$ git log --pretty=oneline 34.0.0..40.0.0 . | wc -l
+ 1453 (up from 1009)
+
+$ git shortlog -sn 34.0.0..40.0.0 . | wc -l
+ 182 (up from 124)
+
+https://crates.io/crates/datafusion/34.0.0
+DataFusion 34 released Dec 17, 2023
+
+https://crates.io/crates/datafusion/40.0.0
+DataFusion 34 released July 12, 2024
+
+Issues created in this time: 321 open, 781 closed (up from 214 open, 437
closed)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+created%3A2023-12-17..2024-07-12
+
+Issues closed: 911 (up from 517)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+closed%3A2023-12-17..2024-07-12
+
+PRs merged in this time 1490 (up from 908)
+https://github.com/apache/arrow-datafusion/pulls?q=is%3Apr+merged%3A2023-12-17..2024-07-12
+
+-->
+
+
+In addition, DataFusion has been appearing publicly more and more, both online
and offline. Here are some highlights:
+
+1. [Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query
Engine], was presented in [SIGMOD '24], one of the major database conferences
+2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around...] from Andy Pavlo and Mike Stonebraker
+3. ["Why you should keep an eye on Apache DataFusion and its community"]
+4. [Apache DataFusion offline meetup in the Bay Area]
+
+
+[DataFusion Comet]: https://datafusion.apache.org/comet/
+[donated]: https://arrow.apache.org/blog/2024/03/06/comet-donation/
+[SIGMOD '24]: https://2024.sigmod.org/
+
+
+[Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query Engine]:
https://dl.acm.org/doi/10.1145/3626246.3653368
+["What Goes Around Comes Around... And Around...]:
https://db.cs.cmu.edu/papers/2024/whatgoesaround-sigmodrec2024.pdf
+["Why you should keep an eye on Apache DataFusion and its community"]:
https://www.cpard.xyz/posts/datafusion/
+[Apache DataFusion offline meetup in the Bay Area]:
https://www.tisonkun.org/2024/07/15/datafusion-meetup-san-francisco/
+
+
+# Improved Performance π
+
+Performance is a key feature of DataFusion, and the community continues to work
+to keep DataFusion state of the art in this area. One major area DataFusion
+improved is the time it takes to convert a SQL query into a plan that can be
+executed. Planning is now almost 2x faster for TPC-DS and TPC-H queries, and
+over 10x faster for some queries with many columns.
+
+Here is a chart showing the improvement due to the concerted effort of many
+contributors including [@jackwener], [@alamb], [@Lordworms], [@dmitrybugakov],
+[@appletreeisyellow], [@ClSlaid], [@rohitrastogi], [@emgeee],
[@kevinmingtarja],
+and [@peter-toth] over several months (see [ticket] for more details)
+
+<img src="{{ site.baseurl
}}/assets/datafusion-40.0.0/improved-planning-time.png" width="700">
+
+[ticket]: https://github.com/apache/datafusion/issues/9637
+
+DataFusion is now up to 40% faster for queries that `GROUP BY` a single string
+or binary column due to a [specialization for single
+Uft8/LargeUtf8/Binary/LargeBinary]. We are working on improving performance
when
+there are [multiple variable length columns in the `GROUP BY` clause].
+
+[specialization for single Uft8/LargeUtf8/Binary/LargeBinary]:
https://github.com/apache/datafusion/pull/8827
+
+We are also in the final phases of [integrating] the new [Arrow StringView]
+which significantly improves performance for workloads that scan, filter and
+group by variable length string and binary data. We expect the improvement to
be
+especially pronounced for Parquet files due to [upstream work in the parquet
+reader]. Kudos to [@XiangpengHong], [@AriesDevil], [@PsiACE], [@Weijun-H],
+[@a10y], and [@RinChanNOWWW] for driving this project.
+
+[integrating]: https://github.com/apache/datafusion/issues/10918
+[Arrow StringView]:
https://docs.rs/arrow/latest/arrow/array/struct.GenericByteViewArray.html
+[multiple variable length columns in the `GROUP BY` clause]:
https://github.com/apache/datafusion/issues/9403
+[upstream work in the parquet reader]:
https://github.com/apache/arrow-rs/issues/5530
+
+# Improved Quality π
+
+DataFusion continues to improve overall in quality. In addition to ongoing bug
+fixes, one of the most exciting improvements is the addition of a new
[SQLancer]
+based [DataFusion Fuzzing] suite thanks to [@2010YOUY01] that has already found
+several bugs and thanks to [@jonahgao], [@tshauck], [@xinlifoobar],
+[@LorrensP-2158466] for fixing them so fast.
+
+[DataFusion Fuzzing]: https://github.com/apache/datafusion/issues/11030
+
+
+## Improved Documentation π
+
+We continue to improve the documentation to make it easier to get started
using DataFusion with
+the [Library Users Guide], [API documentation], and [Examples].
+
+Some notable new examples include:
+* [sql_analysis.rs] to analyse SQL queries with DataFusion structures (thanks
[@LorrensP-2158466])
+* [function_factory.rs] to create custom functions via SQL (thanks
[@milenkovicm])
+* [plan_to_sql.rs] to generate SQL from DataFusion Expr and LogicalPlan
(thanks [@edmondop])
+* [parquet_index.rs] and [advanced_parquet_index.rs] for parquet indexing,
described more below (thanks [@alamb])
+
+[Library Users Guide]:
https://datafusion.apache.org/library-user-guide/index.html
+[API documentation]: https://docs.rs/datafusion/latest/datafusion/index.html
+[Examples]: https://github.com/apache/datafusion/tree/main/datafusion-examples
+[sql_analysis.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/sql_analysis.rs
+[plan_to_sql.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+# New Features β¨
+
+There are too many new features in the last 6 months to list them all, but here
+are some highlights:
+
+## SQL
+* Support for`UNNEST` (thanks [@duongcongtoai], [@JasonLi-cn] and
[@jayzhan211])
+* Support for [Recursive CTEs] (thanks [@jonahgao] and [@matthewgapp])
+* Support for `CREATE FUNCTION` (see below)
+* Many new SQL functions
+
+[Recursive CTEs]: https://github.com/apache/datafusion/issues/462
+
+DataFusion now has much improved support for structured types such a `STRUCT`,
+`LIST`/`ARRAY` and `MAP`. For example, you can now use syntax like:
+
+```rust
+> select {'foo': {'bar': 2}};
++--------------------------------------------------------------+
+| named_struct(Utf8("foo"),named_struct(Utf8("bar"),Int64(2))) |
++--------------------------------------------------------------+
+| {foo: {bar: 2}} |
++--------------------------------------------------------------+
+1 row(s) fetched.
+Elapsed 0.002 seconds.
+```
+
+## SQL Unparser (SQL Formatter)
+
+DataFusion now supports converting `Expr`s and `LogicalPlan`s BACK to SQL text.
+This can be useful in query federation to push predicates down into other
+systems that only accept SQL, and for building systems that generate SQL.
+
+For example, you can now convert a logical expression back to SQL text:
+
+```rust
+// Form a logical expression that represents the SQL "a < 5 OR a = 8"
+let expr = col("a").lt(lit(5)).or(col("a").eq(lit(8)));
+// convert the expression back to SQL text
+let sql = expr_to_sql(&expr)?.to_string();
+assert_eq!(sql, "a < 5 OR a = 8");
+```
+
+You can also do complex things like parsing SQL, modifying the plan, and
convert
+it back to SQL:
+
+```rust
+let df = ctx
+ // Use SQL to read some data from the parquet file
+ .sql("SELECT int_col, double_col, CAST(date_string_col as VARCHAR) FROM
alltypes_plain")
+ .await?;
+// Programmatically add new filters `id > 1 and tinyint_col < double_col`
+let df =
df.filter(col("id").gt(lit(1)).and(col("tinyint_col").lt(col("double_col"))))?
+// Convert the new logical plan back to SQL
+let sql = plan_to_sql(df.logical_plan())?.to_string();
+assert_eq!(sql,
+ "SELECT alltypes_plain.int_col, alltypes_plain.double_col,
CAST(alltypes_plain.date_string_col AS VARCHAR) \
+ FROM alltypes_plain WHERE ((alltypes_plain.id > 1) AND
(alltypes_plain.tinyint_col < alltypes_plain.double_col))")
+);
+```
+
+See the [Plan to SQL example] or the APIs [expr_to_sql] and [plan_to_sql] for
more details.
+
+[expr_to_sql]:
https://docs.rs/datafusion/latest/datafusion/sql/unparser/fn.expr_to_sql.html
+[plan_to_sql]:
https://docs.rs/datafusion/latest/datafusion/sql/unparser/fn.plan_to_sql.html
+[Plan to SQL example]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+
+
+## Low Level APIs for Fast Parquet Access (indexing)
+
+With their rising prevalence, supporting efficient access to Parquet files
+stored remotely on object storage is important. Part of doing this efficiently
+is to minimize the number of object stpre requests made by caching metadata and
Review Comment:
```suggestion
is to minimize the number of object store requests made by caching metadata
and
```
##########
_posts/2024-07-23-datafusion-40.0.0.md:
##########
@@ -0,0 +1,492 @@
+---
+layout: post
+title: "Apache DataFusion 40.0.0 Released"
+date: "2024-07-21 00:00:00"
+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 %}
+-->
+
+<!-- see https://github.com/apache/datafusion/issues/9602 for details -->
+
+## Introduction
+
+We are proud to announce [DataFusion 40.0.0]. This blog highlights some of the
+many major improvements since we released [DataFusion 34.0.0] and a preview of
+what the community is thinking about in the next 6 months. We are hoping to
make
+more regular blog posts -- if you are interested in helping write them, please
+reach out!
+
+[DataFusion 34.0.0]:
https://datafusion.apache.org/blog/2024/01/19/datafusion-34.0.0/
+[DataFusion 40.0.0]: https://crates.io/crates/datafusion/40.0.0
+
+[Apache DataFusion] is an extensible query engine, written in [Rust], that
+uses [Apache Arrow] as its in-memory format. DataFusion is used by developers
to
+create new, fast data centric systems such as databases, dataframe libraries,
+machine learning and streaming applications. While [DataFusionβs primary design
+goal] is to accelerate the creation of other data centric systems, it has a
+reasonable experience directly out of the box as a [dataframe library] and
+[command line SQL tool].
+
+[DataFusionβs primary design goal]:
https://datafusion.apache.org/user-guide/introduction.html#project-goals
+[dataframe library]: https://datafusion.apache.org/python/
+[command line SQL tool]: https://datafusion.apache.org/user-guide/cli/
+
+[apache datafusion]: https://datafusion.apache.org/
+[apache arrow]: https://arrow.apache.org
+[rust]: https://www.rust-lang.org/
+
+DataFusion's core thesis is that as a community together, we can build much
more
+advanced technology than any of us as individuals or companies could do alone.
+Without DataFusion, highly performant vectorized query engines would remain
+the domain of a few large companies and world-class research institutions.
+With DataFusion, we can all build on top of a shared foundation, and focus on
+what makes our projects unique.
+
+
+# Community Growth π
+
+In the last 6 months, between `34.0.0` and `40.0.0`, our community continues to
+grow in new and exciting ways.
+
+1. DataFusion became a top level Apache Software Foundation project (read the
+ [press release] and [blog post]).
+2. We added several PMC members and new
+ committers [@comphead], [@mustafasrepo], [@ozankabak] joined the PMC,
+ [@jonahgao] and [@lewiszlw] joined as a committer. See the [mailing list]
for
+ more details.
+3. [DataFusion Comet] was [donated] and is nearing its first release.
+4. In the [core DataFusion repo] alone we reviewed and accepted almost 1500
PRs from 182 different
+ committers, created over 1000 issues and closed 781 of them π. This is up
+ almost 50% from our last post (1000 PRs from 124 committers with 650 issues
+ created in our last post) π€―. All changes are listed in the detailed
+ [CHANGELOG].
+5. DataFusion focused meetups happened or are happening in multiple cities
+ around the world: [Austin], [San Francisco], [Hangzhou], [New York], and
+ [Belgrade].
+6. Many new projects started in the [datafusion-contrib] organization,
including
+ [Table Providers], [SQLancer], [Open Variant], [JSON], and [ORC].
+
+[core DataFusion repo]: https://github.com/apache/arrow-datafusion
+[CHANGELOG]:
https://github.com/apache/datafusion/blob/main/datafusion/CHANGELOG.md
+[press release]:
https://news.apache.org/foundation/entry/apache-software-foundation-announces-new-top-level-project-apache-datafusion
+[blog post]: https://datafusion.apache.org/blog/2024/05/07/datafusion-tlp/
+[mailing list]: https://lists.apache.org/list.html?d...@datafusion.apache.org
+[Austin]: https://github.com/apache/datafusion/discussions/8522
+[San Francisco]: https://github.com/apache/datafusion/discussions/10800
+[Hangzhou]: https://www.huodongxing.com/event/5761971909400?td=1965290734055
+[New York]: https://github.com/apache/datafusion/discussions/11213
+[Belgrade]: https://github.com/apache/datafusion/discussions/11431
+[datafusion-contrib]: https://github.com/datafusion-contrib
+[Table Providers]:
https://github.com/datafusion-contrib/datafusion-table-providers
+[SQLancer]: https://github.com/datafusion-contrib/datafusion-sqlancer
+[Open Variant]:
https://github.com/datafusion-contrib/datafusion-functions-variant
+[JSON]: https://github.com/datafusion-contrib/datafusion-functions-json
+[ORC]: https://github.com/datafusion-contrib/datafusion-orc
+
+<!--
+$ git log --pretty=oneline 34.0.0..40.0.0 . | wc -l
+ 1453 (up from 1009)
+
+$ git shortlog -sn 34.0.0..40.0.0 . | wc -l
+ 182 (up from 124)
+
+https://crates.io/crates/datafusion/34.0.0
+DataFusion 34 released Dec 17, 2023
+
+https://crates.io/crates/datafusion/40.0.0
+DataFusion 34 released July 12, 2024
+
+Issues created in this time: 321 open, 781 closed (up from 214 open, 437
closed)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+created%3A2023-12-17..2024-07-12
+
+Issues closed: 911 (up from 517)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+closed%3A2023-12-17..2024-07-12
+
+PRs merged in this time 1490 (up from 908)
+https://github.com/apache/arrow-datafusion/pulls?q=is%3Apr+merged%3A2023-12-17..2024-07-12
+
+-->
+
+
+In addition, DataFusion has been appearing publicly more and more, both online
and offline. Here are some highlights:
+
+1. [Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query
Engine], was presented in [SIGMOD '24], one of the major database conferences
+2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around...] from Andy Pavlo and Mike Stonebraker
+3. ["Why you should keep an eye on Apache DataFusion and its community"]
+4. [Apache DataFusion offline meetup in the Bay Area]
+
+
+[DataFusion Comet]: https://datafusion.apache.org/comet/
+[donated]: https://arrow.apache.org/blog/2024/03/06/comet-donation/
+[SIGMOD '24]: https://2024.sigmod.org/
+
+
+[Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query Engine]:
https://dl.acm.org/doi/10.1145/3626246.3653368
+["What Goes Around Comes Around... And Around...]:
https://db.cs.cmu.edu/papers/2024/whatgoesaround-sigmodrec2024.pdf
+["Why you should keep an eye on Apache DataFusion and its community"]:
https://www.cpard.xyz/posts/datafusion/
+[Apache DataFusion offline meetup in the Bay Area]:
https://www.tisonkun.org/2024/07/15/datafusion-meetup-san-francisco/
+
+
+# Improved Performance π
+
+Performance is a key feature of DataFusion, and the community continues to work
+to keep DataFusion state of the art in this area. One major area DataFusion
+improved is the time it takes to convert a SQL query into a plan that can be
+executed. Planning is now almost 2x faster for TPC-DS and TPC-H queries, and
+over 10x faster for some queries with many columns.
+
+Here is a chart showing the improvement due to the concerted effort of many
+contributors including [@jackwener], [@alamb], [@Lordworms], [@dmitrybugakov],
+[@appletreeisyellow], [@ClSlaid], [@rohitrastogi], [@emgeee],
[@kevinmingtarja],
+and [@peter-toth] over several months (see [ticket] for more details)
+
+<img src="{{ site.baseurl
}}/assets/datafusion-40.0.0/improved-planning-time.png" width="700">
+
+[ticket]: https://github.com/apache/datafusion/issues/9637
+
+DataFusion is now up to 40% faster for queries that `GROUP BY` a single string
+or binary column due to a [specialization for single
+Uft8/LargeUtf8/Binary/LargeBinary]. We are working on improving performance
when
+there are [multiple variable length columns in the `GROUP BY` clause].
+
+[specialization for single Uft8/LargeUtf8/Binary/LargeBinary]:
https://github.com/apache/datafusion/pull/8827
+
+We are also in the final phases of [integrating] the new [Arrow StringView]
+which significantly improves performance for workloads that scan, filter and
+group by variable length string and binary data. We expect the improvement to
be
+especially pronounced for Parquet files due to [upstream work in the parquet
+reader]. Kudos to [@XiangpengHong], [@AriesDevil], [@PsiACE], [@Weijun-H],
+[@a10y], and [@RinChanNOWWW] for driving this project.
+
+[integrating]: https://github.com/apache/datafusion/issues/10918
+[Arrow StringView]:
https://docs.rs/arrow/latest/arrow/array/struct.GenericByteViewArray.html
+[multiple variable length columns in the `GROUP BY` clause]:
https://github.com/apache/datafusion/issues/9403
+[upstream work in the parquet reader]:
https://github.com/apache/arrow-rs/issues/5530
+
+# Improved Quality π
+
+DataFusion continues to improve overall in quality. In addition to ongoing bug
+fixes, one of the most exciting improvements is the addition of a new
[SQLancer]
+based [DataFusion Fuzzing] suite thanks to [@2010YOUY01] that has already found
+several bugs and thanks to [@jonahgao], [@tshauck], [@xinlifoobar],
+[@LorrensP-2158466] for fixing them so fast.
+
+[DataFusion Fuzzing]: https://github.com/apache/datafusion/issues/11030
+
+
+## Improved Documentation π
+
+We continue to improve the documentation to make it easier to get started
using DataFusion with
+the [Library Users Guide], [API documentation], and [Examples].
+
+Some notable new examples include:
+* [sql_analysis.rs] to analyse SQL queries with DataFusion structures (thanks
[@LorrensP-2158466])
+* [function_factory.rs] to create custom functions via SQL (thanks
[@milenkovicm])
+* [plan_to_sql.rs] to generate SQL from DataFusion Expr and LogicalPlan
(thanks [@edmondop])
+* [parquet_index.rs] and [advanced_parquet_index.rs] for parquet indexing,
described more below (thanks [@alamb])
+
+[Library Users Guide]:
https://datafusion.apache.org/library-user-guide/index.html
+[API documentation]: https://docs.rs/datafusion/latest/datafusion/index.html
+[Examples]: https://github.com/apache/datafusion/tree/main/datafusion-examples
+[sql_analysis.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/sql_analysis.rs
+[plan_to_sql.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+# New Features β¨
+
+There are too many new features in the last 6 months to list them all, but here
+are some highlights:
+
+## SQL
+* Support for`UNNEST` (thanks [@duongcongtoai], [@JasonLi-cn] and
[@jayzhan211])
+* Support for [Recursive CTEs] (thanks [@jonahgao] and [@matthewgapp])
+* Support for `CREATE FUNCTION` (see below)
+* Many new SQL functions
+
+[Recursive CTEs]: https://github.com/apache/datafusion/issues/462
+
+DataFusion now has much improved support for structured types such a `STRUCT`,
+`LIST`/`ARRAY` and `MAP`. For example, you can now use syntax like:
+
+```rust
+> select {'foo': {'bar': 2}};
++--------------------------------------------------------------+
+| named_struct(Utf8("foo"),named_struct(Utf8("bar"),Int64(2))) |
++--------------------------------------------------------------+
+| {foo: {bar: 2}} |
++--------------------------------------------------------------+
+1 row(s) fetched.
+Elapsed 0.002 seconds.
+```
+
+## SQL Unparser (SQL Formatter)
+
+DataFusion now supports converting `Expr`s and `LogicalPlan`s BACK to SQL text.
+This can be useful in query federation to push predicates down into other
+systems that only accept SQL, and for building systems that generate SQL.
+
+For example, you can now convert a logical expression back to SQL text:
+
+```rust
+// Form a logical expression that represents the SQL "a < 5 OR a = 8"
+let expr = col("a").lt(lit(5)).or(col("a").eq(lit(8)));
+// convert the expression back to SQL text
+let sql = expr_to_sql(&expr)?.to_string();
+assert_eq!(sql, "a < 5 OR a = 8");
+```
+
+You can also do complex things like parsing SQL, modifying the plan, and
convert
+it back to SQL:
+
+```rust
+let df = ctx
+ // Use SQL to read some data from the parquet file
+ .sql("SELECT int_col, double_col, CAST(date_string_col as VARCHAR) FROM
alltypes_plain")
+ .await?;
+// Programmatically add new filters `id > 1 and tinyint_col < double_col`
+let df =
df.filter(col("id").gt(lit(1)).and(col("tinyint_col").lt(col("double_col"))))?
+// Convert the new logical plan back to SQL
+let sql = plan_to_sql(df.logical_plan())?.to_string();
+assert_eq!(sql,
+ "SELECT alltypes_plain.int_col, alltypes_plain.double_col,
CAST(alltypes_plain.date_string_col AS VARCHAR) \
+ FROM alltypes_plain WHERE ((alltypes_plain.id > 1) AND
(alltypes_plain.tinyint_col < alltypes_plain.double_col))")
+);
+```
+
+See the [Plan to SQL example] or the APIs [expr_to_sql] and [plan_to_sql] for
more details.
+
+[expr_to_sql]:
https://docs.rs/datafusion/latest/datafusion/sql/unparser/fn.expr_to_sql.html
+[plan_to_sql]:
https://docs.rs/datafusion/latest/datafusion/sql/unparser/fn.plan_to_sql.html
+[Plan to SQL example]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+
+
+## Low Level APIs for Fast Parquet Access (indexing)
+
+With their rising prevalence, supporting efficient access to Parquet files
+stored remotely on object storage is important. Part of doing this efficiently
+is to minimize the number of object stpre requests made by caching metadata and
+skipping over parts of the file that are not needed (e.g. via an index).
+
+DataFusion's Parquet reader has long internally supported advanced predicate
+pushdown by reading the parquet metadata from the file footer and pruning based
+on row group level statistics as well as data page level statistics. DataFusion
+now also supports users supplying their own low level pruning information via
+the [`ParquetAccessPlan`] API.
+
+This API can be used along with index information to selectively skip decoding
+parts of the file. This feature has been used by SpiceAI to add [efficient
+support] for reading from DeltaLake tables and handling [deletion vectors].
+
+```text
+ βββββββββββββββββββββββββ If the RowSelection does not include any
+ β ... β rows from a particular Data Page, that
+ β β Data Page is not fetched or decoded.
+ β βββββββββββββββββββββ β Note this requires a PageIndex
+ β β ββββββββββββ β β
+Row β β βDataPage 0β β β ββββββββββββββββββββββ
+Groups β β ββββββββββββ β β β β
+ β β ββββββββββββ β β β ParquetExec β
+ β β ... βDataPage 1β ββΌ βΌ β β β β (Parquet Reader) β
+ β β ββββββββββββ β β β β β β β ββ β
+ β β ββββββββββββ β β β βββββββββββββββββ β
+ β β βDataPage 2β β β If only rows β βParquetMetadataβ β
+ β β ββββββββββββ β β from DataPage 1 β βββββββββββββββββ β
+ β βββββββββββββββββββββ β are selected, ββββββββββββββββββββββ
+ β β only DataPage 1
+ β ... β is fetched and
+ β β decoded
+ β βββββββββββββββββββββ β
+ β β Thrift metadata β β
+ β βββββββββββββββββββββ β
+ βββββββββββββββββββββββββ
+ Parquet File
+```
+
+See the [parquet_index.rs] and [advanced_parquet_index.rs] examples for more
details.
+
+Thanks to [@alamb] and [@Ted-Jiang] for this feature.
+
+[`ParquetAccessPlan`]:
https://docs.rs/datafusion/latest/datafusion/datasource/physical_plan/parquet/struct.ParquetAccessPlan.html
+[efficient support]: https://github.com/spiceai/spiceai/pull/1891
+[deletion vectors]: https://docs.delta.io/latest/delta-deletion-vectors.html
+[parquet_index.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/parquet_index.rs
+[advanced_parquet_index.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/advanced_parquet_index.rs
+
+# Building Systems is Easier with DataFusion π οΈ
+
+In addition to make small API improvements, there are several new APIs that
make
+it easier to build systems on top of DataFusion, for example:
+
+* Faster and easier to use [TreeNode API] for traversing and manipulating
plans and expressions.
+* All functions now use the same [Scalar User Defined Function API], making it
easier to customize
+ DataFusion's behavior without sacrificing performance. See [ticket] for more
details.
+* DataFusion can now be compiled to [WASM].
+
+[TreeNode API]:
https://docs.rs/datafusion/latest/datafusion/common/tree_node/trait.TreeNode.html#overview
+[Scalar User Defined Function API]:
https://docs.rs/datafusion/latest/datafusion/logical_expr/trait.ScalarUDFImpl.html
+[ticket]: https://github.com/apache/arrow-datafusion/issues/8045
+[WASM]: https://github.com/apache/datafusion/discussions/9834
+
+## User Defined SQL Parsing Extensions
+
+As of DataFusion 40.0.0, the [`ExprPlanner`] allows easy extension of
+DataFusion's SQL planner to support custom operators or syntax.
+
+For example the [datafusion-functions-json] project uses this API add support
+for JSON operators in SQL queries. It provides a custom implementation for
+planning JSON operators such as `->` and `->>` with code like:
+
+```rust
+struct MyCustomPlanner;
+
+impl ExprPlanner for MyCustomPlanner {
+ // Provide custom implementation for planning a binary operators
+ // such as `->` and `->>`
+ fn plan_binary_op(
+ &self,
+ expr: RawBinaryExpr,
+ _schema: &DFSchema,
+ ) -> Result<PlannerResult<RawBinaryExpr>> {
+ match &expr.op {
+ BinaryOperator::Arrow => { /* plan -> operator */ }
+ BinaryOperator::LongArrow => { /* plan ->> operator */ }
+ ...
+ }
+ }
+}
+```
+
+Thanks to [@samuelcolvin], [@jayzhan211] and [@dharanad] for helping make this
+feature happen.
+
+[datafusion-functions-json]:
https://github.com/datafusion-contrib/datafusion-functions-json
+[`ExprPlanner`]:
https://docs.rs/datafusion/latest/datafusion/logical_expr/planner/trait.ExprPlanner.html
+
+## Pluggable Support for `CREATE FUNCTION`
+
+DataFusion's new [`FunctionFactory`] API let's users provide a handler for
+`CREATE FUNCTION` in SQL. This feature lets you build systems that support
+defining functions in SQL such as
+
+```sql
+-- SQL based functions
+CREATE FUNCTION my_func(DOUBLE, DOUBLE) RETURNS DOUBLE
+ RETURN $1 + $3
+;
+
+-- ML Models
+CREATE FUNCTION iris(FLOAT[]) RETURNS FLOAT[] LANGUAGE TORCH AS
'models:/iris@champion';
+
+-- WebAssembly
+CREATE FUNCTION func(FLOAT[]) RETURNS FLOAT[] LANGUAGE WASM AS 'func.wasm'
+```
+
+Huge thanks to [@milenkovicm] for this feature. There is an example of how to
+make macro like functions in the [function_factory.rs] example. It would be
+great if [someone made a demo] showing how easy WASM udfs is to do π£.
+
+[fucntion_factory.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/function_factory.rs
Review Comment:
```suggestion
[function_factory.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/function_factory.rs
```
##########
_posts/2024-07-23-datafusion-40.0.0.md:
##########
@@ -0,0 +1,492 @@
+---
+layout: post
+title: "Apache DataFusion 40.0.0 Released"
+date: "2024-07-21 00:00:00"
+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 %}
+-->
+
+<!-- see https://github.com/apache/datafusion/issues/9602 for details -->
+
+## Introduction
+
+We are proud to announce [DataFusion 40.0.0]. This blog highlights some of the
+many major improvements since we released [DataFusion 34.0.0] and a preview of
+what the community is thinking about in the next 6 months. We are hoping to
make
+more regular blog posts -- if you are interested in helping write them, please
+reach out!
+
+[DataFusion 34.0.0]:
https://datafusion.apache.org/blog/2024/01/19/datafusion-34.0.0/
+[DataFusion 40.0.0]: https://crates.io/crates/datafusion/40.0.0
+
+[Apache DataFusion] is an extensible query engine, written in [Rust], that
+uses [Apache Arrow] as its in-memory format. DataFusion is used by developers
to
+create new, fast data centric systems such as databases, dataframe libraries,
+machine learning and streaming applications. While [DataFusionβs primary design
+goal] is to accelerate the creation of other data centric systems, it has a
+reasonable experience directly out of the box as a [dataframe library] and
+[command line SQL tool].
+
+[DataFusionβs primary design goal]:
https://datafusion.apache.org/user-guide/introduction.html#project-goals
+[dataframe library]: https://datafusion.apache.org/python/
+[command line SQL tool]: https://datafusion.apache.org/user-guide/cli/
+
+[apache datafusion]: https://datafusion.apache.org/
+[apache arrow]: https://arrow.apache.org
+[rust]: https://www.rust-lang.org/
+
+DataFusion's core thesis is that as a community together, we can build much
more
+advanced technology than any of us as individuals or companies could do alone.
+Without DataFusion, highly performant vectorized query engines would remain
+the domain of a few large companies and world-class research institutions.
+With DataFusion, we can all build on top of a shared foundation, and focus on
+what makes our projects unique.
+
+
+# Community Growth π
+
+In the last 6 months, between `34.0.0` and `40.0.0`, our community continues to
+grow in new and exciting ways.
+
+1. DataFusion became a top level Apache Software Foundation project (read the
+ [press release] and [blog post]).
+2. We added several PMC members and new
+ committers [@comphead], [@mustafasrepo], [@ozankabak] joined the PMC,
+ [@jonahgao] and [@lewiszlw] joined as a committer. See the [mailing list]
for
+ more details.
+3. [DataFusion Comet] was [donated] and is nearing its first release.
+4. In the [core DataFusion repo] alone we reviewed and accepted almost 1500
PRs from 182 different
+ committers, created over 1000 issues and closed 781 of them π. This is up
+ almost 50% from our last post (1000 PRs from 124 committers with 650 issues
+ created in our last post) π€―. All changes are listed in the detailed
+ [CHANGELOG].
+5. DataFusion focused meetups happened or are happening in multiple cities
+ around the world: [Austin], [San Francisco], [Hangzhou], [New York], and
+ [Belgrade].
+6. Many new projects started in the [datafusion-contrib] organization,
including
+ [Table Providers], [SQLancer], [Open Variant], [JSON], and [ORC].
+
+[core DataFusion repo]: https://github.com/apache/arrow-datafusion
+[CHANGELOG]:
https://github.com/apache/datafusion/blob/main/datafusion/CHANGELOG.md
+[press release]:
https://news.apache.org/foundation/entry/apache-software-foundation-announces-new-top-level-project-apache-datafusion
+[blog post]: https://datafusion.apache.org/blog/2024/05/07/datafusion-tlp/
+[mailing list]: https://lists.apache.org/list.html?d...@datafusion.apache.org
+[Austin]: https://github.com/apache/datafusion/discussions/8522
+[San Francisco]: https://github.com/apache/datafusion/discussions/10800
+[Hangzhou]: https://www.huodongxing.com/event/5761971909400?td=1965290734055
+[New York]: https://github.com/apache/datafusion/discussions/11213
+[Belgrade]: https://github.com/apache/datafusion/discussions/11431
+[datafusion-contrib]: https://github.com/datafusion-contrib
+[Table Providers]:
https://github.com/datafusion-contrib/datafusion-table-providers
+[SQLancer]: https://github.com/datafusion-contrib/datafusion-sqlancer
+[Open Variant]:
https://github.com/datafusion-contrib/datafusion-functions-variant
+[JSON]: https://github.com/datafusion-contrib/datafusion-functions-json
+[ORC]: https://github.com/datafusion-contrib/datafusion-orc
+
+<!--
+$ git log --pretty=oneline 34.0.0..40.0.0 . | wc -l
+ 1453 (up from 1009)
+
+$ git shortlog -sn 34.0.0..40.0.0 . | wc -l
+ 182 (up from 124)
+
+https://crates.io/crates/datafusion/34.0.0
+DataFusion 34 released Dec 17, 2023
+
+https://crates.io/crates/datafusion/40.0.0
+DataFusion 34 released July 12, 2024
+
+Issues created in this time: 321 open, 781 closed (up from 214 open, 437
closed)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+created%3A2023-12-17..2024-07-12
+
+Issues closed: 911 (up from 517)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+closed%3A2023-12-17..2024-07-12
+
+PRs merged in this time 1490 (up from 908)
+https://github.com/apache/arrow-datafusion/pulls?q=is%3Apr+merged%3A2023-12-17..2024-07-12
+
+-->
+
+
+In addition, DataFusion has been appearing publicly more and more, both online
and offline. Here are some highlights:
+
+1. [Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query
Engine], was presented in [SIGMOD '24], one of the major database conferences
+2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around...] from Andy Pavlo and Mike Stonebraker
+3. ["Why you should keep an eye on Apache DataFusion and its community"]
+4. [Apache DataFusion offline meetup in the Bay Area]
+
+
+[DataFusion Comet]: https://datafusion.apache.org/comet/
+[donated]: https://arrow.apache.org/blog/2024/03/06/comet-donation/
+[SIGMOD '24]: https://2024.sigmod.org/
+
+
+[Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query Engine]:
https://dl.acm.org/doi/10.1145/3626246.3653368
+["What Goes Around Comes Around... And Around...]:
https://db.cs.cmu.edu/papers/2024/whatgoesaround-sigmodrec2024.pdf
+["Why you should keep an eye on Apache DataFusion and its community"]:
https://www.cpard.xyz/posts/datafusion/
+[Apache DataFusion offline meetup in the Bay Area]:
https://www.tisonkun.org/2024/07/15/datafusion-meetup-san-francisco/
+
+
+# Improved Performance π
+
+Performance is a key feature of DataFusion, and the community continues to work
+to keep DataFusion state of the art in this area. One major area DataFusion
+improved is the time it takes to convert a SQL query into a plan that can be
+executed. Planning is now almost 2x faster for TPC-DS and TPC-H queries, and
+over 10x faster for some queries with many columns.
+
+Here is a chart showing the improvement due to the concerted effort of many
+contributors including [@jackwener], [@alamb], [@Lordworms], [@dmitrybugakov],
+[@appletreeisyellow], [@ClSlaid], [@rohitrastogi], [@emgeee],
[@kevinmingtarja],
+and [@peter-toth] over several months (see [ticket] for more details)
+
+<img src="{{ site.baseurl
}}/assets/datafusion-40.0.0/improved-planning-time.png" width="700">
+
+[ticket]: https://github.com/apache/datafusion/issues/9637
+
+DataFusion is now up to 40% faster for queries that `GROUP BY` a single string
+or binary column due to a [specialization for single
+Uft8/LargeUtf8/Binary/LargeBinary]. We are working on improving performance
when
+there are [multiple variable length columns in the `GROUP BY` clause].
+
+[specialization for single Uft8/LargeUtf8/Binary/LargeBinary]:
https://github.com/apache/datafusion/pull/8827
+
+We are also in the final phases of [integrating] the new [Arrow StringView]
+which significantly improves performance for workloads that scan, filter and
+group by variable length string and binary data. We expect the improvement to
be
+especially pronounced for Parquet files due to [upstream work in the parquet
+reader]. Kudos to [@XiangpengHong], [@AriesDevil], [@PsiACE], [@Weijun-H],
+[@a10y], and [@RinChanNOWWW] for driving this project.
+
+[integrating]: https://github.com/apache/datafusion/issues/10918
+[Arrow StringView]:
https://docs.rs/arrow/latest/arrow/array/struct.GenericByteViewArray.html
+[multiple variable length columns in the `GROUP BY` clause]:
https://github.com/apache/datafusion/issues/9403
+[upstream work in the parquet reader]:
https://github.com/apache/arrow-rs/issues/5530
+
+# Improved Quality π
+
+DataFusion continues to improve overall in quality. In addition to ongoing bug
+fixes, one of the most exciting improvements is the addition of a new
[SQLancer]
+based [DataFusion Fuzzing] suite thanks to [@2010YOUY01] that has already found
+several bugs and thanks to [@jonahgao], [@tshauck], [@xinlifoobar],
+[@LorrensP-2158466] for fixing them so fast.
+
+[DataFusion Fuzzing]: https://github.com/apache/datafusion/issues/11030
+
+
+## Improved Documentation π
+
+We continue to improve the documentation to make it easier to get started
using DataFusion with
+the [Library Users Guide], [API documentation], and [Examples].
+
+Some notable new examples include:
+* [sql_analysis.rs] to analyse SQL queries with DataFusion structures (thanks
[@LorrensP-2158466])
+* [function_factory.rs] to create custom functions via SQL (thanks
[@milenkovicm])
+* [plan_to_sql.rs] to generate SQL from DataFusion Expr and LogicalPlan
(thanks [@edmondop])
+* [parquet_index.rs] and [advanced_parquet_index.rs] for parquet indexing,
described more below (thanks [@alamb])
+
+[Library Users Guide]:
https://datafusion.apache.org/library-user-guide/index.html
+[API documentation]: https://docs.rs/datafusion/latest/datafusion/index.html
+[Examples]: https://github.com/apache/datafusion/tree/main/datafusion-examples
+[sql_analysis.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/sql_analysis.rs
+[plan_to_sql.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+# New Features β¨
+
+There are too many new features in the last 6 months to list them all, but here
+are some highlights:
+
+## SQL
+* Support for`UNNEST` (thanks [@duongcongtoai], [@JasonLi-cn] and
[@jayzhan211])
+* Support for [Recursive CTEs] (thanks [@jonahgao] and [@matthewgapp])
+* Support for `CREATE FUNCTION` (see below)
+* Many new SQL functions
+
+[Recursive CTEs]: https://github.com/apache/datafusion/issues/462
+
+DataFusion now has much improved support for structured types such a `STRUCT`,
+`LIST`/`ARRAY` and `MAP`. For example, you can now use syntax like:
+
+```rust
+> select {'foo': {'bar': 2}};
++--------------------------------------------------------------+
+| named_struct(Utf8("foo"),named_struct(Utf8("bar"),Int64(2))) |
++--------------------------------------------------------------+
+| {foo: {bar: 2}} |
++--------------------------------------------------------------+
+1 row(s) fetched.
+Elapsed 0.002 seconds.
+```
+
+## SQL Unparser (SQL Formatter)
+
+DataFusion now supports converting `Expr`s and `LogicalPlan`s BACK to SQL text.
+This can be useful in query federation to push predicates down into other
+systems that only accept SQL, and for building systems that generate SQL.
+
+For example, you can now convert a logical expression back to SQL text:
+
+```rust
+// Form a logical expression that represents the SQL "a < 5 OR a = 8"
+let expr = col("a").lt(lit(5)).or(col("a").eq(lit(8)));
+// convert the expression back to SQL text
+let sql = expr_to_sql(&expr)?.to_string();
+assert_eq!(sql, "a < 5 OR a = 8");
+```
+
+You can also do complex things like parsing SQL, modifying the plan, and
convert
+it back to SQL:
+
+```rust
+let df = ctx
+ // Use SQL to read some data from the parquet file
+ .sql("SELECT int_col, double_col, CAST(date_string_col as VARCHAR) FROM
alltypes_plain")
+ .await?;
+// Programmatically add new filters `id > 1 and tinyint_col < double_col`
+let df =
df.filter(col("id").gt(lit(1)).and(col("tinyint_col").lt(col("double_col"))))?
+// Convert the new logical plan back to SQL
+let sql = plan_to_sql(df.logical_plan())?.to_string();
+assert_eq!(sql,
+ "SELECT alltypes_plain.int_col, alltypes_plain.double_col,
CAST(alltypes_plain.date_string_col AS VARCHAR) \
+ FROM alltypes_plain WHERE ((alltypes_plain.id > 1) AND
(alltypes_plain.tinyint_col < alltypes_plain.double_col))")
+);
+```
+
+See the [Plan to SQL example] or the APIs [expr_to_sql] and [plan_to_sql] for
more details.
+
+[expr_to_sql]:
https://docs.rs/datafusion/latest/datafusion/sql/unparser/fn.expr_to_sql.html
+[plan_to_sql]:
https://docs.rs/datafusion/latest/datafusion/sql/unparser/fn.plan_to_sql.html
+[Plan to SQL example]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/plan_to_sql.rs
+
+
+
+## Low Level APIs for Fast Parquet Access (indexing)
+
+With their rising prevalence, supporting efficient access to Parquet files
+stored remotely on object storage is important. Part of doing this efficiently
+is to minimize the number of object stpre requests made by caching metadata and
+skipping over parts of the file that are not needed (e.g. via an index).
+
+DataFusion's Parquet reader has long internally supported advanced predicate
+pushdown by reading the parquet metadata from the file footer and pruning based
+on row group level statistics as well as data page level statistics. DataFusion
+now also supports users supplying their own low level pruning information via
+the [`ParquetAccessPlan`] API.
+
+This API can be used along with index information to selectively skip decoding
+parts of the file. This feature has been used by SpiceAI to add [efficient
+support] for reading from DeltaLake tables and handling [deletion vectors].
+
+```text
+ βββββββββββββββββββββββββ If the RowSelection does not include any
+ β ... β rows from a particular Data Page, that
+ β β Data Page is not fetched or decoded.
+ β βββββββββββββββββββββ β Note this requires a PageIndex
+ β β ββββββββββββ β β
+Row β β βDataPage 0β β β ββββββββββββββββββββββ
+Groups β β ββββββββββββ β β β β
+ β β ββββββββββββ β β β ParquetExec β
+ β β ... βDataPage 1β ββΌ βΌ β β β β (Parquet Reader) β
+ β β ββββββββββββ β β β β β β β ββ β
+ β β ββββββββββββ β β β βββββββββββββββββ β
+ β β βDataPage 2β β β If only rows β βParquetMetadataβ β
+ β β ββββββββββββ β β from DataPage 1 β βββββββββββββββββ β
+ β βββββββββββββββββββββ β are selected, ββββββββββββββββββββββ
+ β β only DataPage 1
+ β ... β is fetched and
+ β β decoded
+ β βββββββββββββββββββββ β
+ β β Thrift metadata β β
+ β βββββββββββββββββββββ β
+ βββββββββββββββββββββββββ
+ Parquet File
+```
+
+See the [parquet_index.rs] and [advanced_parquet_index.rs] examples for more
details.
+
+Thanks to [@alamb] and [@Ted-Jiang] for this feature.
+
+[`ParquetAccessPlan`]:
https://docs.rs/datafusion/latest/datafusion/datasource/physical_plan/parquet/struct.ParquetAccessPlan.html
+[efficient support]: https://github.com/spiceai/spiceai/pull/1891
+[deletion vectors]: https://docs.delta.io/latest/delta-deletion-vectors.html
+[parquet_index.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/parquet_index.rs
+[advanced_parquet_index.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/advanced_parquet_index.rs
+
+# Building Systems is Easier with DataFusion π οΈ
+
+In addition to make small API improvements, there are several new APIs that
make
+it easier to build systems on top of DataFusion, for example:
+
+* Faster and easier to use [TreeNode API] for traversing and manipulating
plans and expressions.
+* All functions now use the same [Scalar User Defined Function API], making it
easier to customize
+ DataFusion's behavior without sacrificing performance. See [ticket] for more
details.
+* DataFusion can now be compiled to [WASM].
+
+[TreeNode API]:
https://docs.rs/datafusion/latest/datafusion/common/tree_node/trait.TreeNode.html#overview
+[Scalar User Defined Function API]:
https://docs.rs/datafusion/latest/datafusion/logical_expr/trait.ScalarUDFImpl.html
+[ticket]: https://github.com/apache/arrow-datafusion/issues/8045
+[WASM]: https://github.com/apache/datafusion/discussions/9834
+
+## User Defined SQL Parsing Extensions
+
+As of DataFusion 40.0.0, the [`ExprPlanner`] allows easy extension of
+DataFusion's SQL planner to support custom operators or syntax.
+
+For example the [datafusion-functions-json] project uses this API add support
+for JSON operators in SQL queries. It provides a custom implementation for
+planning JSON operators such as `->` and `->>` with code like:
+
+```rust
+struct MyCustomPlanner;
+
+impl ExprPlanner for MyCustomPlanner {
+ // Provide custom implementation for planning a binary operators
+ // such as `->` and `->>`
+ fn plan_binary_op(
+ &self,
+ expr: RawBinaryExpr,
+ _schema: &DFSchema,
+ ) -> Result<PlannerResult<RawBinaryExpr>> {
+ match &expr.op {
+ BinaryOperator::Arrow => { /* plan -> operator */ }
+ BinaryOperator::LongArrow => { /* plan ->> operator */ }
+ ...
+ }
+ }
+}
+```
+
+Thanks to [@samuelcolvin], [@jayzhan211] and [@dharanad] for helping make this
+feature happen.
+
+[datafusion-functions-json]:
https://github.com/datafusion-contrib/datafusion-functions-json
+[`ExprPlanner`]:
https://docs.rs/datafusion/latest/datafusion/logical_expr/planner/trait.ExprPlanner.html
+
+## Pluggable Support for `CREATE FUNCTION`
+
+DataFusion's new [`FunctionFactory`] API let's users provide a handler for
+`CREATE FUNCTION` in SQL. This feature lets you build systems that support
+defining functions in SQL such as
+
+```sql
+-- SQL based functions
+CREATE FUNCTION my_func(DOUBLE, DOUBLE) RETURNS DOUBLE
+ RETURN $1 + $3
+;
+
+-- ML Models
+CREATE FUNCTION iris(FLOAT[]) RETURNS FLOAT[] LANGUAGE TORCH AS
'models:/iris@champion';
+
+-- WebAssembly
+CREATE FUNCTION func(FLOAT[]) RETURNS FLOAT[] LANGUAGE WASM AS 'func.wasm'
+```
+
+Huge thanks to [@milenkovicm] for this feature. There is an example of how to
+make macro like functions in the [function_factory.rs] example. It would be
+great if [someone made a demo] showing how easy WASM udfs is to do π£.
+
+[fucntion_factory.rs]:
https://github.com/apache/datafusion/blob/main/datafusion-examples/examples/function_factory.rs
+[someone made a demo]: https://github.com/apache/datafusion/issues/9326
+
+[`FunctionFactory`]:
https://docs.rs/datafusion/latest/datafusion/execution/context/trait.FunctionFactory.html
+
+# Looking Ahead: The Next Six Months π
+
+The community has been [discussing what we will work on in the next six
months].
+Some major initiatives from that discussion are:
+
+1. *Aggregate Performance*: Improve the speed of [aggregating "high
cardinality"]
+ data when there are many (e.g. millions) of distinct groups.
+
+2. *Modularity*: Make DataFusion even more modular, by completely unifying
+ built in and user [aggregate functions] and [window functions].
+
+3. *LogicalTypes*: [Introducing Logical Types] to make it easier to use
+ different encodings like `StringView`, `RunEnd` and `Dictionary` arrays as
well
+ as user defined types. Thanks [@notfilippo] for driving this.
+
+4. *Improved Documentation*: Write blog posts and videos explaining
+ how to use DataFusion for real-world use cases.
+
+5. *Testing*: Improve CI infrastructure and test coverage, more fuzz
+ testing, and better functional and performance regression testing.
+
+
+[discussing what we will work on in the next six months]:
https://github.com/apache/datafusion/issues/11442
+[aggregating "high cardinality"]:
https://github.com/apache/arrow-datafusion/issues/7000
+[Improved statistics handling]:
https://github.com/apache/arrow-datafusion/issues/8227
Review Comment:
I don't think this is referenced
##########
_posts/2024-07-23-datafusion-40.0.0.md:
##########
@@ -0,0 +1,492 @@
+---
+layout: post
+title: "Apache DataFusion 40.0.0 Released"
+date: "2024-07-21 00:00:00"
+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 %}
+-->
+
+<!-- see https://github.com/apache/datafusion/issues/9602 for details -->
+
+## Introduction
+
+We are proud to announce [DataFusion 40.0.0]. This blog highlights some of the
+many major improvements since we released [DataFusion 34.0.0] and a preview of
+what the community is thinking about in the next 6 months. We are hoping to
make
+more regular blog posts -- if you are interested in helping write them, please
+reach out!
+
+[DataFusion 34.0.0]:
https://datafusion.apache.org/blog/2024/01/19/datafusion-34.0.0/
+[DataFusion 40.0.0]: https://crates.io/crates/datafusion/40.0.0
+
+[Apache DataFusion] is an extensible query engine, written in [Rust], that
+uses [Apache Arrow] as its in-memory format. DataFusion is used by developers
to
+create new, fast data centric systems such as databases, dataframe libraries,
+machine learning and streaming applications. While [DataFusionβs primary design
+goal] is to accelerate the creation of other data centric systems, it has a
+reasonable experience directly out of the box as a [dataframe library] and
+[command line SQL tool].
+
+[DataFusionβs primary design goal]:
https://datafusion.apache.org/user-guide/introduction.html#project-goals
+[dataframe library]: https://datafusion.apache.org/python/
+[command line SQL tool]: https://datafusion.apache.org/user-guide/cli/
+
+[apache datafusion]: https://datafusion.apache.org/
+[apache arrow]: https://arrow.apache.org
+[rust]: https://www.rust-lang.org/
+
+DataFusion's core thesis is that as a community together, we can build much
more
+advanced technology than any of us as individuals or companies could do alone.
+Without DataFusion, highly performant vectorized query engines would remain
+the domain of a few large companies and world-class research institutions.
+With DataFusion, we can all build on top of a shared foundation, and focus on
+what makes our projects unique.
+
+
+# Community Growth π
+
+In the last 6 months, between `34.0.0` and `40.0.0`, our community continues to
+grow in new and exciting ways.
+
+1. DataFusion became a top level Apache Software Foundation project (read the
+ [press release] and [blog post]).
+2. We added several PMC members and new
+ committers [@comphead], [@mustafasrepo], [@ozankabak] joined the PMC,
+ [@jonahgao] and [@lewiszlw] joined as a committer. See the [mailing list]
for
+ more details.
+3. [DataFusion Comet] was [donated] and is nearing its first release.
+4. In the [core DataFusion repo] alone we reviewed and accepted almost 1500
PRs from 182 different
+ committers, created over 1000 issues and closed 781 of them π. This is up
+ almost 50% from our last post (1000 PRs from 124 committers with 650 issues
+ created in our last post) π€―. All changes are listed in the detailed
+ [CHANGELOG].
+5. DataFusion focused meetups happened or are happening in multiple cities
+ around the world: [Austin], [San Francisco], [Hangzhou], [New York], and
+ [Belgrade].
+6. Many new projects started in the [datafusion-contrib] organization,
including
+ [Table Providers], [SQLancer], [Open Variant], [JSON], and [ORC].
+
+[core DataFusion repo]: https://github.com/apache/arrow-datafusion
+[CHANGELOG]:
https://github.com/apache/datafusion/blob/main/datafusion/CHANGELOG.md
+[press release]:
https://news.apache.org/foundation/entry/apache-software-foundation-announces-new-top-level-project-apache-datafusion
+[blog post]: https://datafusion.apache.org/blog/2024/05/07/datafusion-tlp/
+[mailing list]: https://lists.apache.org/list.html?d...@datafusion.apache.org
+[Austin]: https://github.com/apache/datafusion/discussions/8522
+[San Francisco]: https://github.com/apache/datafusion/discussions/10800
+[Hangzhou]: https://www.huodongxing.com/event/5761971909400?td=1965290734055
+[New York]: https://github.com/apache/datafusion/discussions/11213
+[Belgrade]: https://github.com/apache/datafusion/discussions/11431
+[datafusion-contrib]: https://github.com/datafusion-contrib
+[Table Providers]:
https://github.com/datafusion-contrib/datafusion-table-providers
+[SQLancer]: https://github.com/datafusion-contrib/datafusion-sqlancer
+[Open Variant]:
https://github.com/datafusion-contrib/datafusion-functions-variant
+[JSON]: https://github.com/datafusion-contrib/datafusion-functions-json
+[ORC]: https://github.com/datafusion-contrib/datafusion-orc
+
+<!--
+$ git log --pretty=oneline 34.0.0..40.0.0 . | wc -l
+ 1453 (up from 1009)
+
+$ git shortlog -sn 34.0.0..40.0.0 . | wc -l
+ 182 (up from 124)
+
+https://crates.io/crates/datafusion/34.0.0
+DataFusion 34 released Dec 17, 2023
+
+https://crates.io/crates/datafusion/40.0.0
+DataFusion 34 released July 12, 2024
+
+Issues created in this time: 321 open, 781 closed (up from 214 open, 437
closed)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+created%3A2023-12-17..2024-07-12
+
+Issues closed: 911 (up from 517)
+https://github.com/apache/arrow-datafusion/issues?q=is%3Aissue+closed%3A2023-12-17..2024-07-12
+
+PRs merged in this time 1490 (up from 908)
+https://github.com/apache/arrow-datafusion/pulls?q=is%3Apr+merged%3A2023-12-17..2024-07-12
+
+-->
+
+
+In addition, DataFusion has been appearing publicly more and more, both online
and offline. Here are some highlights:
+
+1. [Apache Arrow DataFusion: A Fast, Embeddable, Modular Analytic Query
Engine], was presented in [SIGMOD '24], one of the major database conferences
+2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around...] from Andy Pavlo and Mike Stonebraker
Review Comment:
```suggestion
2. As part of the trend to define "the POSIX of databases" in ["What Goes
Around Comes Around... And Around..."] from Andy Pavlo and Mike Stonebraker
```
Missing end quote maybe?
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