Docs: add example of how to read parquet row groups in parallel#9396
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Feb 17, 2026
| /// Each [`ParquetRecordBatchStream`] is independent and can be used to read | ||
| /// from the same underlying source in parallel. Use | ||
| /// [`ParquetRecordBatchStream::next_row_group`] with a single stream to | ||
| /// begin prefetching the next Row Group. To read a read in parallel, create |
alamb
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Feb 17, 2026
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etseidl
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Apr 20, 2026
| /// )?; | ||
| /// let mut streams = vec![]; | ||
| /// for row_group_index in 0..10 { | ||
| /// // each stream needs its own source instance to issue parallel IO requests, so we clone the file for each stream |
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nit: could break this line, it gets pretty wide when rendered
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Thanks again @etseidl |
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…he#9396) # Which issue does this PR close? - Closes apache#9381 # Rationale for this change It is possible to read a parquet file in parallel today using the arrow-rs APIs (making an individual reader to read individual parts), however, it is not always obvious how to do so as @pmarks observes on apache#9381 # What changes are included in this PR? Add additional documentation explaining how to read files in parallel, along with a doc example Here is an example of what it looks like rendered: <img width="1054" height="1050" alt="Screenshot 2026-02-11 at 5 33 02 PM" src="https://github.com/user-attachments/assets/abfbbb8f-24de-427e-97dd-71977540255f" /> # Are these changes tested? By CI # Are there any user-facing changes? more docs; No functional changes
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Which issue does this PR close?
Rationale for this change
It is possible to read a parquet file in parallel today using the arrow-rs APIs (making an individual reader to read individual parts), however, it is not always obvious how to do so as @pmarks observes on #9381
What changes are included in this PR?
Add additional documentation explaining how to read files in parallel, along with a doc example
Here is an example of what it looks like rendered:
Are these changes tested?
By CI
Are there any user-facing changes?
more docs; No functional changes