datafusion-contrib / datafusion-contrib/orc-rust
Support decoding Union column into DenseUnion
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- Dominant language
- Rust
- Stars
- 30
- Forks
- 26
- Avg merge
- 19m
- Merged PRs (30d)
- 3
Description
Initial Union support will decode to Sparse Union: https://github.com/datafusion-contrib/datafusion-orc/commit/ee69b91cb2ce4c18ee5148bd541658d362fc577f
Can try give option to prefer decoding to DenseUnion: https://arrow.apache.org/docs/format/Columnar.html#dense-union
- Since ORC already encodes data in a dense manner (omitting nulls in the data streams) so might be more efficient? Unknown, just something to keep in mind
Contributor guide
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First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reviewing commit ee69b91cb2ce4c18ee5148bd541658d362fc577f and the Apache Arrow dense union format linked in the issue. Determine how Union columns currently decode to SparseUnion and what an option to prefer DenseUnion would entail; done means Union decoding supports that preference without losing existing behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- data-engineering
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 32/100