tustvold commented on issue #7647: URL: https://github.com/apache/arrow-datafusion/issues/7647#issuecomment-1879197118
> This could especially impact multi-phase grouping where dictionary encoding will save significant time hashing values for low cardinality string columns. If anything this is precisely the case where the old behaviour was especially inefficient. It will compute the rows, expanding the dictionary, perform the grouping, convert the rows back to strings, convert the strings back to dictionaries, convert back to strings in the row format, again expanding the dictionaries, and repeat for each stage -- 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]
