DataFusion weekly project plan (Andrew Lamb) - June 17, 2024

[alamb]

Follow on to #10869

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)

Externally Facing Nes

• Keynote presentation for SiMoD workshop at SIGMOD 2024 #10481 Keynote went well
• SIGMOD paper published officially (ACM page), talk went well: Create presentation for DataFusion SIGMOD 2024 paper #10480
• @lewiszlw became a committer and @waynexia and @ozankabak joined the PMC 🎉
• Meetup next week in SF organized by @cpard and @emgeee: DISCUSSION: DataFusion Meetup in San Francisco Bay Area USA #10340
• Meetup in China being organized in July by @waynexia and @tisonkun : DISCUSSION: DataFusion Meetup in China #10341 (comment)

Feature Highlights

• We are in the final phases of converting all aggregate functions thanks to @goldmedal with this , @dharanad with this @ejbyfeldt with this and @Lordworms with this
• Final example for building an external index is looking very nice Advanced example for building an external index for Row Groups *within* parquet files #10580
• Substrait is becoming much better supported thanks to @Blizzara in this , this and others, and @Lordwords implementing tests
• We updated to 52.0.0 thanks to @waynexia build(deps): update Arrow/Parquet to 52.0, object-store to 0.10 #10765 🎉

My (personal) plans for this week

• Check out @Max-Meldrum's example index from Indexing Support in DataFusion? #9963 (reply in thread)
• Help @jayzhan211 with Improve performance for grouping by variable length columns (strings) #9403
• Work on some better examples of sql analysis with @LorrensP-2158466 and @goldmedal such as Add example for writing SQL analysis using DataFusion structures #10938

Project Queue (list of future projects)

Projects I plan to help actively help review / plan

• [EPIC] Implement StringViewArray and BinaryViewArray arrow-rs#5374 with @XiangpengHao and others
• [EPIC] Continued correct and improved extracting Parquet statistics into ArrayRefs  #10922 (with @marvinlanhenke @Weijun-H and others)

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 that I think are strategically important
5. Other new features / additions to functionality (note this is the lowest)

The top strategically important projects in my head are:

• 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)
• Anything that improves DataFusion's quality such as bug fixes, and improved / expanded tests, etc
• Making function packages modular and easier to mix/match
• Improved performance (with benchmarks)

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

[alamb]

Review Queue:

• Improve CommonSubexprEliminate identifier management (10% faster planning) #10473
• feat: Support duplicate column names in Joins in Substrait consumer #11049
• Support COPY TO Externally Defined File Formats, add FileType trait #11060
• Introduce the DynamicFileCatalog in datafusion-catalog #11035
• Feat: Implement hf:// / "hugging face" integration in datafusion-cli #10792
• Resolve empty relation opt for join types #11066

Arrow

• Provide Arrow Schema Hint to Parquet Reader - Alternative 2 arrow-rs#5939

[alamb]

Next week: #11106