Follow on to #11710

My (personal) North ⭐ : 1000 projects are built using DataFusion 📈

It would be great for other contributors to DataFusion to to make them visible somehow as well 🙏 (feel free to copy / modify the format of this ticket)

External news

• DataFusion 40 is now in ClickBench rankings: https://benchmark.clickhouse.com thanks to @pmcgleenon

https://ossrank.com/p/1573-apache-arrow-datafusion

Here is a fun chart showing the growth of contributors over the last few years (before 2020 is somewhat skewed as the code as in the main arrow monoreop at that time

Major Discussions (Please Take a Look)

• Logical Types: [Proposal] Decouple logical from physical types #11513 from @notfilippo

Upcoming Meetups

• New York, NY, USA DataFusion Meetup: Tuesday Sep 17th 2024, 5:30PM - 8:30PM Manhattan #11213
• DataFusion Belgrade Meetup 2024/09/27 #11431

Highlights last week

• After an epic amount of work, @edmondop, @jayzhan211 and others migrated the last aggregate functions (min/max) to user defined aggregates and removed the "built in" aggregate distinction.
• We declared "success" on initial StringView implementation in arrow-rs and DataFusion
• We are now hard at work making StringView better / on by default, thanks to @xinlifoobar , @tshauck, @XiangpengHao, @a10y and others for starting us off strong there
• We merged the first from @Rachelint and second from @korowa of what I expect will be a series of performance improvements for ClickBench queries over the next few months
• @lewiszlw keeps pounding out features and improvements that improve the codebase ❤ 🧑‍🍳
• @goldmedal made it possible to Support planning Map literal #11780

SELECT MAP {'a':1, 'b':2, 'c':3};
----
{a: 1, b: 2, c: 3}

My (personal) plans for this week

• Continue to review and organize StringView: [Epic] Complete Initial StringView in DataFusion #11752
• Contribute to performance via: Avoid extra copies in CoalesceBatchesExec to improve performance #7957
• Work down the review backlogs (arrow-rs backlog is still going in the wrong direction 😭 )
• File follow on tickets for outstanding projects like the physical optimizer move

Projects I plan to help actively help review / push forward

• High Cardinality Grouping: [Epic] High cardinality aggregation performance wishlist #11679
• StringView integration [Epic] Complete Initial StringView in DataFusion #11752

Algorithm for (my) prioritizing PR reviews

Note there are many committers who can and do review and merge PRs, so this is not the priorities of the project as a whole, just the approximate algorithm I use to prioritize my own time.

Priority:

1. Bug fixes (where something is just incorrect), especially regressions (where it used to work and now does not)
2. Improvements directly related to features needed for InfluxDB (my employer)
3. Documentation and test improvements (I view these as very strategically important)
4. PRs for other features I think are strategically important (See below)
5. Other new features / additions to functionality (note this is the lowest on purpose)

The top strategically important projects in my head are:

• Improved performance (with benchmarks -- this is high in my mind now)
• Anything that improves DataFusion's quality such as bug fixes, and improved / expanded tests, etc
• Anything that makes it easier to use DataFusion as a user (docs, examples, better APIs, etc), including Getting started guide for new users (who want to use DataFusion in their project)

Thus, if you are interested in contributing to DataFusion and are interested in a fast turn around time I would recommend looking into bug fixes / test improvements / documentation or the projects named above.

If you propose adding new functionality, especially if the PR is large/complex and not connected to a wider need, the review cycle will likely be longer. You can make it a shorter cycle by looking at the comments on other recent PRs and following the same model (e.g. ensure there are tests in sqllogictest for example, the CI passes, includes documentation, etc)

Background

The idea of this ticket is make my plans for DataFusion visible, largely for my own personal organizational needs, but also to:

1. Communicate / coordinate in the community
2. Help provide an interesting summary of what is happening in DataFusion this week (both for my future self and others)