DataFusion weekly project plan (Andrew Lamb) - Sep 2, 2024

[alamb]

Follow on to #12066

My (personal) North ⭐ : 1000 projects are built using DataFusion 📈
( Getting closer all the time )

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

• demonstration of how uwheel is integrated into DataFusion https://uwheel.rs/post/datafusion_uwheel/ (@Max-Meldrum )
• integrating StringView into DataFusion part 1: https://www.influxdata.com/blog/faster-queries-with-stringview-part-one-influxdb/

Major Discussions (Please Take a Look)

• None at the moment

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 from last week

• Will return next week -- I was out for 1.5 weeks and am behind

My (personal) plans for this week

• complete board report September 2024 ASF Board Report #10156
• Work down the review backlog

Projects I plan to help actively help review / push forward

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

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 priority on purpose)

The top strategically important projects in my head are:

• 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)
• Improved performance (with benchmarks -- this is high in my mind now)

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. break it into small PRs, 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)

[alamb]

Review Queue

DataFusion (bugs / improvements)

• Fix Possible Congestion Scenario in SortPreservingMergeExec #12302
• Add value_from_statisics to AggregateUDFImpl, remove special case for min/max/count aggregate statistics #12296
• Fix issue with "to_date" failing to process dates later than year 2262 #12227
• fix: preserve qualifiers when rewriting expressions #12341

DataFusion (StringView):

• Improve StringView support for SUBSTR #12044
• Coerce BinaryView/Utf8View to LargeBinary/LargeUtf8 on output. #12271
• Fix parquet statistics for ListingTable and Utf8View with schema_force_string_view, rename config option to schema_force_view_types #12232
• Support substrait serialization for ScalarValue::Utf8View and ScalarValue::BinaryView #12118

DataFusion (performance):

• feat: Add projection to FilterExec #12281
• Return TableProviderFilterPushDown::Exact when Parquet Pushdown Enabled #12135
• Impl convert_to_state for GroupsAccumulatorAdapter (faster median for high cardinality aggregates) #11827
• Sketch for aggregation intermediate results blocked management #11943
• Avoid RowConverter for multi column grouping (10% faster clickbench queries) #12269

DataFusion (new features, lower priority for me):

• Support for SIMILAR TO for physical plan #12350
• dynamic file provider: Introduce the DynamicFileCatalog in datafusion-catalog #11035
• Implement SHOW FUNCTIONS #12266
• Adding node_id to ExecutionPlanProperties #12186
• include input fields as output for Substrait consumer #12225
• Add additional regexp function regexp_count() #12080
• Support skewness(x) in Aggregation function #12295
• Remove LargeUtf8|Binary, Utf8|BinaryView, and Dictionary from ScalarValue #11978

Arrow-rs

• Benchmark for bit_mask (set_bits) arrow-rs#6353
• Support StringViewArray interop with python: fix lingering C Data Interface issues for *ViewArray arrow-rs#6368
• Improve performance of set_bits by avoiding to set individual bits arrow-rs#6288
• Implement native support StringViewArray for regexp_is_match and regexp_is_match_scalar function, deprecate regexp_is_match_utf8 and regexp_is_match_utf8_scalar arrow-rs#6376
• Parquet: Verify 32-bit CRC checksum when decoding pages arrow-rs#6290
• feat: add Allocator type param to MutableBuffer arrow-rs#6336

sqlparser-rs

• With Order Support for Memory Tables datafusion-sqlparser-rs#1401

[alamb]

Review queue Friday Sep 6

sqlparser-rs:

• Merge Fix INTERVAL parsing to support expressions and units via dialect datafusion-sqlparser-rs#1398

[alamb]

next week: #12391