foxtail463 opened a new pull request, #66354: URL: https://github.com/apache/doris/pull/66354
Problem Summary: A scalar count(distinct) runs its global aggregate hash-shuffled by the distinct key (non-empty partitionExpressions), i.e. in parallel across BEs. But the cost model set the parallelism factor from group-by keys alone, so with no group by it used factor = 1, costing the aggregate as single-point. This overestimated the parallel plan and made CBO reject it. Solution: Treat a global aggregate as partitioned when it has group by keys or non-empty partitionExpressions, and scale its cost by beNumber accordingly. -- 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]
