starocean999 opened a new issue, #9838: URL: https://github.com/apache/incubator-doris/issues/9838
### Search before asking - [X] I had searched in the [issues](https://github.com/apache/incubator-doris/issues?q=is%3Aissue) and found no similar issues. ### Description Group by operator is kind of time cosuming, especially for string column. However, some string column are low cardinality and can be dict encoded. We can take advantage of the dict encoded integer values in group by operator instead of the original strings to get much better performance. ### Solution add low_cardinality keyword. use "alter table xxx modify column yyy low_cardinality true;" to set the column yyy as low cardinality. The the column would be dict encoded and in group by operator, we can use integer dict code instead of strings. ### Are you willing to submit PR? - [X] Yes I am willing to submit a PR! ### Code of Conduct - [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct) -- 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: commits-unsubscr...@doris.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
