0xPoe commented on code in PR #16956: URL: https://github.com/apache/datafusion/pull/16956#discussion_r2267819416
########## datafusion/physical-plan/src/joins/hash_join.rs: ########## @@ -892,21 +892,56 @@ impl ExecutionPlan for HashJoinExec { } fn partition_statistics(&self, partition: Option<usize>) -> Result<Statistics> { - if partition.is_some() { - return Ok(Statistics::new_unknown(&self.schema())); + match (partition, self.mode) { + // For CollectLeft mode, the left side is collected into a single partition, + // so all left partitions are available to each output partition. + // For the right side, we need the specific partition statistics. + (Some(partition), PartitionMode::CollectLeft) => { + let left_stats = self.left.partition_statistics(None)?; + let right_stats = self.right.partition_statistics(Some(partition))?; + + let stats = estimate_join_statistics( + left_stats, + right_stats, + self.on.clone(), + &self.join_type, + &self.join_schema, + )?; + Ok(stats.project(self.projection.as_ref())) + } + + // For Partitioned mode, both sides are partitioned, so each output partition + // only has access to the corresponding partition from both sides. + (Some(partition), PartitionMode::Partitioned) => { + let left_stats = self.left.partition_statistics(Some(partition))?; + let right_stats = self.right.partition_statistics(Some(partition))?; + + let stats = estimate_join_statistics( + left_stats, + right_stats, + self.on.clone(), + &self.join_type, + &self.join_schema, + )?; + Ok(stats.project(self.projection.as_ref())) + } + + // For Auto mode or when no specific partition is requested, fall back to Review Comment: Oh, I see. However, it seems challenging to get the threshold here for conducting the same evaluation. Do you have any other ideas on how to share the same logic from the `JoinSelection` to determine the PartitionMode? I'm uncertain how to obtain the optimizer config for accessing the threshold settings in the current API design. -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org