andygrove commented on PR #2993: URL: https://github.com/apache/datafusion-comet/pull/2993#issuecomment-3887022322
> Hi @coderfender. > > That's a good question. I implemented `spark_translate` here because Andy created issue #2976 in this project so I didn’t think too much at the time. > > Upon checking DataFusion [`translate`](https://github.com/apache/datafusion/blob/main/datafusion/functions/src/unicode/translate.rs), I noticed two differences compared to [Spark's](https://github.com/apache/spark/blob/eec092c9f9d1ad3df0390b1ea56340c1103ba887/common/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java#L1593): > > 1. It sets `graphemes(true)`, while Spark uses codepoints, which might lead to incompatibility > 2. It uses last-occurrence-wins for duplicates, while Spark uses first-occurrence-wins. > > For example: > > ``` > ❯ datafusion-cli > DataFusion CLI v51.0.0 > > SELECT translate('abcbcb', 'bcbc', '1234') AS result; > +--------+ > | result | > +--------+ > | a34343 | > +--------+ > 1 row(s) fetched. > Elapsed 0.005 seconds. > ``` > > ``` > ❯ spark-sql > spark-sql (default)> SELECT translate('abcbcb', 'bcbc', '1234'); > a12121 > Time taken: 1.273 seconds, Fetched 1 row(s) > ``` > > I'm not very familiar with the DataFusion project so I could be wrong, but pushing the changes upstream could affect other use cases in DataFusion. Apologies for not reviewing this PR sooner. I agree with @shuch3ng that the Comet requirements are not compatible with the DataFusion implementation. It makes sense to implement in this repo, or to eventually upstream to the `data fusion-spark` crate in the DataFusion repo. -- 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]
