schlosna opened a new issue, #41573: URL: https://github.com/apache/arrow/issues/41573
### Describe the bug, including details regarding any error messages, version, and platform. While reviewing allocation profiling of an Arrow intensive application, I noticed significant allocations due to `ArrayList#grow()` originating from `org.apache.arrow.vector.VectorSchemaRoot#getFieldVectors()`. The `org.apache.arrow.vector.VectorSchemaRoot#getFieldVectors()` method uses an inefficient `fieldVectors.stream().collect(Collectors.toList())` to create a list copy, leading to reallocations as the target list is collected. This could be replaced with a more efficent `new ArrayList<>(fieldVectors)` to make a pre-sized list copy, or even better an unmodifiable view via `Collections.unmodifiableList(fieldVectors)`. ### Component(s) Java -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
