neilconway opened a new pull request, #20305: URL: https://github.com/apache/datafusion/pull/20305
## Which issue does this PR close? - Closes #20302. ## Rationale for this change The `translate()` is commonly invoked with constant values for its second and third arguments. We can take advantage of that to significantly optimize its performance by precomputing the translation lookup table, rather than recomputing it for every row. For scalar ASCII inputs, this yields roughly a 10x performance improvement. For scalar UTF8 inputs, the performance improvement is more like 50%, although less so for long strings. ## What changes are included in this PR? * Add a benchmark for scalar/constant input to translate * Add a missing test case * Improve translate() docs * Support translate() on LargeUtf8 input (AFAICS there is no reason this shouldn't be supported?) * Optimize translate() for scalar inputs by precomputing lookup hashmap * Optimize translate() for ASCII inputs by precomputing ASCII byte-wise lookup table ## Are these changes tested? Yes. Added an extra test case and did a bunch of benchmarking. ## 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]
