DataFusion weekly project plan (Andrew Lamb) - May 20, 2024

[alamb]

Follow on to #10482

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

It would be great for other contributors to DataFusion who plan non trivial work could try to make them visible somehow as well 🙏 (feel free to copy / modify the format)

My Highlights from Last Week

• Completed the Expr --> SQL (Complete support for Expr --> String  #9726) thanks to @xinlifoobar @reswqa, @goldmedal @edmondop and others
• @berkaysynnada and @ozankabak made the UDF analysis framework much more general: PhysicalExpr Orderings with Range Information #10504
• @jayzhan211 is cranking along extracting Aggregates from the core Support UDAF to align Builtin aggregate function #10493
• (a week late) @comphead and @mustafasrepo joined the PMC, @jonahgao joined as a committer. See the mailing list threads here here and here.
• @comphead and @viirya are improving SortMergeJoin Fix SortMergeJoin with join filter filtering all rows out #10495
• @NGA-TRAN and I made significant progress making an API to work with parquet statistics [EPIC] Efficiently and correctly extract parquet statistics into ArrayRefs #10453

My (personal) plans for this week

TLDR is I plan to keep trying to make parquet support better (documentation and examples)

• Document ParquetExec more (so it is clear / easier to understand what is already supported)
• Help @NGA-TRAN with [EPIC] Efficiently and correctly extract parquet statistics into ArrayRefs #10453
• Complete Example for building an external index for parquet files #10546
• Create presentation for DataFusion SIGMOD 2024 paper #10480
• Make ASF public press release #10403
• Help @tustvold complete Structured ByteView Access (underlying StringView/BinaryView representation) arrow-rs#5736 (likely by reviewing)

Project Queue (list of future projects)

• API in ParquetExec to pass in RowSelections to ParquetExec (enable custom indexes, finer grained pushdown) #9929 (likely not this week)
• (Stretch) Stop copying Exprs and LogicalPlans so much during Common Subexpression Elimination #9873 copies (last part of [EPIC] Stop copying LogicalPlan during OptimizerPasses #9637)
• In general, help [EPIC] Implement StringViewArray and BinaryViewArray arrow-rs#5374 more actively as it seems to be stuck

Projects I plan to help actively help review / plan

• [EPIC] Support converting Exprs and LogicalPlans --> SQL Strings #9494

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]

Next week: #10699