DataFusion weekly project plan (Andrew Lamb) - March 25, 2024

[alamb]

Follow on to #9675

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

• We have begin LogicalPlan / Expr --> String translation ([EPIC] Support converting Exprs and LogicalPlans --> SQL Strings #9494)
• Large scale "extract scalar functions from the core" continues at good pace way [Epic] Port BuiltInFunctons to datafusion-functions-* crates #9285 (thanks @jayzhan211 and @erenavsarogullari and @Omega359 for being a machine here)
• Bloom filters are getting better (e.g. parquet: Add support for Bloom filters on binary columns #9644) -- thanks to @progval
• We are ready for the 37.0.0 release Release DataFusion 37.0.0 #9682

My (personal) goals for this project

1000 projects are built using DataFusion 📈

My (personal) plans for this week

• Submit SIGMOD final draft feedback : Finalize SIGMOD 2024 paper ~(if accepted)~ #8373 (10 days left)
• Run UPDATE: VENUE IS FULL Invitation: Mar 25, 2024 DataFusion meetup before the DataCouncil March 2024 in Austin TX #8522
• Make at least one PR for [EPIC] Stop copying LogicalPlan during OptimizerPasses #9637

Project Queue (list of future projects)

Projects I plan to help actively help review / plan

• [EPIC] Implement StringViewArray and BinaryViewArray arrow-rs#5374
• [Epic] Port BuiltInFunctons to datafusion-functions-* crates #9285
• Supporting using parallel parquet writer outside of Datafusion query execution #9493 with @wiedld

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: [EPIC] Unify Function Interface (remove BuiltInScalarFunction) #8045

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, 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]

DataFusion

• Projection Pushdown through user defined LogicalPlan nodes. #9690
• Expose parser on DFParser to enable user controlled parsing #9729
• Support custom struct field names with new scalar function named_struct #9743
• feat: eliminate redundant sorts on monotonic expressions #9813
• Implement semi/anti join output statistics estimation #9800
• fix: duplicate output for HashJoinExec in CollectLeft mode #9757
• Allow declaring partition columns in PARTITION BY clause, backwards compatible #9599
• feat: Use file cache to list partitions if available #9655
• Prepare 37.0.0 Release #9697
• Support ORDER BY in AggregateUDF #9249
• Add support for Bloom filters on unsigned integer columns in Parquet tables #9770
• feat: Add display_pg_json for LogicalPlan #9789
• [Epic] Unify AggregateFunction Interface (remove built in list of AggregateFunction s), improve the system #8708
• CI: releasing CLI to PyPI #9452

arrow-rs

• feat: support reading and writingStringView and BinaryView in parquet (part 2) arrow-rs#5557

Sqlparser

• Add support for DuckDB struct literal syntax datafusion-sqlparser-rs#1194

[MohamedAbdeen21]

Hey @alamb, on the topic of making datafusion easier to use, can you take a look at #9452 ? I think everyone has pip and it would be great to have the cli there.

As mentioned, it needs some feedback as I'm not familiar with the release cycle, but it is a good starting point

[alamb]

Hey @alamb, on the topic of making datafusion easier to use, can you take a look at #9452 ? I think everyone has pip and it would be great to have the cli there.

Hi @MohamedAbdeen21 -- thank you I will indeed try and look at this PR later this week. I am sorry I am traveling this week and thus my review bandwidth is very limited. I expect to be back with more bandwidth later in the week

[alamb]

Next week: #9899