DataFusion weekly project plan (Andrew Lamb) - Feb 5, 2024

[alamb]

Follow on to Jan 29, 2024

Note: I will be traveling this week so I will likely have less time to devote to DataFusion

Boilerplate Introduction

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

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 (personal) goals for this project

1000 projects are built using DataFusion 📈

My (personal) plans for this week

• Continue work to break out functions (e.g. datafusion-functions-array crate) Create datafusion-functions-array crate and move ArrayToString function into it #9113 and related infrastructure Add FunctionRegistry::register_udaf and FunctionRegistry::register_udwf #9075
• Continue to improve ClickBench performance Faster String Aggregation (this is my personal fun project)
• More advanced pruning predicates Don't error on unknown column when pruning if predicate can still be proven false #7869 with @appletreeisyellow

Project Queue (list of future projects)

• Improved Statistics: Epic: Statistics improvements #8227 (specifically, Introduce a way to represent constrained statistics / bounds on values in Statistics #8078)

Projects I plan to help actively help review / plan

• Improve planning speed [Epic] A collection of issues to improve planning performance / speed / efficiency #5637 with @matthewmturner
• Hardening Recursive CTEs Add support for recursive CTEs #462 with @matthewgapp and @jonahgao

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
• Improving performance of aggregation - especially high cardinality groupings, where we still lag state of the art by 2x

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)

[alamb]

Review Queue

Sqlparser

• feat: add mysql show status statement datafusion-sqlparser-rs#1119
• BigQuery: Parse optional DELETE FROM statement datafusion-sqlparser-rs#1120
• Add support for UPDATE FROM for SQLite (further to #694) datafusion-sqlparser-rs#1117
• BigQuery: support of CREATE VIEW IF NOT EXISTS datafusion-sqlparser-rs#1118

[alamb]

DataFusion

• Support join filter for SortMergeJoin #9080
• Support Copy with Remote Object Stores in datafusion-cli #9064
• Update parse_protobuf_file_scan_config to remove any partition columns from the file_schema in FileScanConfig #9126 (review)
• feat: add github action to self-assign the issue #9132
• fix: schema metadata retrieval when listing parquet table #9134 (review)
• Change ScalarValue::Struct to ArrayRef #7893

Arrow-rs

• feat: support casting FixedSizeList with new child type arrow-rs#5360 (review)

[alamb]

DataFusion

• Consider table scan filter during analysis of optimize projections #9131
• Partial Sort Plan Implementation #9125 (review)

[alamb]

DataFusion

• Fix NULL values in FixedSizeList creation #9141

[alamb]

DataFusion

• Add regexp_like, improve docs and examples for regexp_match` #9137
• feat: add ability to query the remote http(s) location directly in datafusion-cli #9150
• minor: fix error message function naming #9168

Sqlparser

• Restrain JSON_TABLE table function parsing to MySqlDialect and AnsiDialect datafusion-sqlparser-rs#1123
• feat: support = operator in function args datafusion-sqlparser-rs#1128
• feat: add duckdb "INSTALL" and "LOAD" datafusion-sqlparser-rs#1127

[alamb]

DataFusion

• Use prep_null_mask_filter to handle nulls in selection mask #9163
• [Document] Adding UDF by impl ScalarUDFImpl #9172
• Fix sphinx warnings #9142
• Add cargo audit CI #9182
• Use concat to simplify Nested Scalar creation #9174
• feat: support FixedSizeList Type Coercion #9108
• feat: support block gzip for streams #9175

[alamb]

Next week: #9200