Rich-T-kid opened a new issue, #22891: URL: https://github.com/apache/datafusion/issues/22891
### Is your feature request related to a problem or challenge? `GroupValuesDictionary` can provide up to a 2-5x speedup over `GroupValuesRows` for aggregations, but it is only used when the input data is already a dictionary-encoded column. ### Describe the solution you'd like A physical optimizer rule could inspect column statistics at plan time and cast low-medium cardinality Utf8 columns to `Dictionary(Int32, Utf8)` before aggregation, allowing GroupValuesDictionary to be selected automatically without any changes from the user. Parquet files keep metadata about cardinality, this may be a good place to start ### Describe alternatives you've considered _No response_ ### Additional context https://github.com/apache/datafusion/pull/21765 -- 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]
