You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues-all@impala.apache.org by "Steve Carlin (Jira)" <ji...@apache.org> on 2025/06/01 17:18:00 UTC
[jira] [Assigned] (IMPALA-13587) Calcite planner: outer join not aggregating nulls properly
[ https://issues.apache.org/jira/browse/IMPALA-13587?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Steve Carlin reassigned IMPALA-13587:
-------------------------------------
Assignee: Steve Carlin
> Calcite planner: outer join not aggregating nulls properly
> ----------------------------------------------------------
>
> Key: IMPALA-13587
> URL: https://issues.apache.org/jira/browse/IMPALA-13587
> Project: IMPALA
> Issue Type: Sub-task
> Reporter: Steve Carlin
> Assignee: Steve Carlin
> Priority: Major
>
> The following query is producing incorrect results:
> select t2.int_col y from alltypessmall t1 left outer join alltypestiny t2 on t1.int_col = t2.int_col group by 1
> ... due to nulls not being aggregated properly on multiple nodes. This is because the value equivalency graph is being set for the join conjunct on an outer join. When a hash join partition node is being used, there is an optimization that skips the aggregation step that combines groups across nodes if, based on the value transfer graph, it deduces that all data for the partition column is being sent to the same node.
> The bug here is that even though an outer join is using an equi-conjunct, the left and right side are different when data is not found on the outer join side, where it becomse null.
> The fix is to avoid registering the equi-conjunct if the values are not always equal.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-all-unsubscribe@impala.apache.org
For additional commands, e-mail: issues-all-help@impala.apache.org