[Java][C] sliced RecordBatch offset info is lost when imported from c-data
- Dominant language
- Java
- Stars
- 94
- Forks
- 152
- Avg merge
- 3d 16h
- Merged PRs (30d)
- 11
Description
### Describe the bug, including details regarding any error messages, version, and platform.
Reproduced on latest arrow release (16.0)
When importing a sliced RecordBatch from c to java
On c side:
```
auto sliced_record_batch = original_record_batch->Slice(/*offset=*/8, /*length=*/2);
arrow::ExportRecordBatch(sliced_record_batch, arrow_array_ptr);
```
On java side:
```
ArrowArray arrowArray = ArrowArray.allocateNew(allocator);
Data.importIntoVectorSchemaRoot(allocator, arrowArray, vectorSchemaRoot, null);
```
The imported vectorSchemaRoot maintains the correct length(which is 2), but the offset info (which is 8) is not respected, hence the content of the imported vectorSchemaRoot points to the first 2 rows of the original_record_batch, while the desired content is sliced_record_batch.
I'm not familiar with arrow code, but it seems that the offset info is actually present in org.apache.arrow.c.ArrowArray.Snapshot, but org.apache.arrow.c.ArrayImporter ignores the offset in org.apache.arrow.c.ArrayImporter.doImport(ArrowArray.Snapshot)
### Component(s)
Java
Contributor guide
Research direction
Start by reading org.apache.arrow.c.ArrayImporter.doImport(ArrowArray.Snapshot) and the offset information in org.apache.arrow.c.ArrowArray.Snapshot. Reproduce the Java import with the C-side sliced RecordBatch, then verify that the imported vectorSchemaRoot contains the rows from the slice offset rather than the first rows of the original batch.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c, java
- Domain
- data-engineering
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Clearly specified
- Newbie friendliness
- 45/100