[data] fix repartitioning empty datasets #54107
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Signed-off-by: Hao Chen <chenh1024@gmail.com>
There was a problem hiding this comment.
Pull Request Overview
This PR fixes the repartitioning behavior for empty datasets and refines the handling of block schemas during repartitioning.
- Added a new test to ensure empty datasets are repartitioned correctly with both shuffling options.
- Updated the block schema handling in the repartition task scheduler, including a default fallback for empty results.
Reviewed Changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| python/ray/data/tests/test_repartition_e2e.py | Added test case for empty dataset repartitioning with both shuffled and non-shuffled options. |
| python/ray/data/_internal/planner/exchange/split_repartition_task_scheduler.py | Refined block schema detection logic and improved error messaging for unknown block schemas. |
Comments suppressed due to low confidence (1)
python/ray/data/tests/test_repartition_e2e.py:210
- [nitpick] Consider adding a docstring to this test function to clarify its purpose and expected behavior when repartitioning an empty dataset.
def test_repartition_empty_datasets(ray_start_regular_shared_2_cpus, shuffle):
python/ray/data/_internal/planner/exchange/split_repartition_task_scheduler.py
Show resolved
Hide resolved
bveeramani
approved these changes
Jun 26, 2025
Comment on lines
+212
to
+213
| num_partitions = 5 | ||
| ds_empty = ray.data.range(100).filter(lambda row: False) |
There was a problem hiding this comment.
Nit: Consider using the simplest inputs to make the intent clearer
Suggested change
| num_partitions = 5 | |
| ds_empty = ray.data.range(100).filter(lambda row: False) | |
| num_partitions = 1 | |
| ds_empty = ray.data.range(1).filter(lambda row: False) |
minerharry
pushed a commit
to minerharry/ray
that referenced
this pull request
Jun 27, 2025
Fix the following error when repartitioning an empty dataset:
```
first_block_schema = reduce_metadata_schema[0].schema
IndexError: list index out of range
```
Signed-off-by: Hao Chen <chenh1024@gmail.com>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fix the following error when repartitioning an empty dataset: