neilconway opened a new pull request, #22182: URL: https://github.com/apache/datafusion/pull/22182
## Which issue does this PR close? - Closes #22181. ## Rationale for this change This PR optimizes `overlay` by switching to the new bulk-NULL string builders, and also taking advantage of `append_with` to avoid copying into an intermediate `String`. Along the way, we also optimize character counting for Unicode inputs, reducing the number of times we need to walk the input string. ## What changes are included in this PR? * Switch to `BulkNullStringArrayBuilder` to build the result set, and `NullBuffer::union_many` to compute NULLs in bulk * Use `append_with` to avoid an intermediate string copy * For Unicode inputs, replace three `char_indices` walks with a single string traversal * More comprehensive benchmark coverage * Fix a misleading/inaccurate error message ## Are these changes tested? Yes, covered by existing tests. ## Are there any user-facing changes? No. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
