himanshu-mishra commented on PR #5406:
URL: https://github.com/apache/hive/pull/5406#issuecomment-2320251464
> This is a good candidate to fix this issue, but have you checked why the
reducer traits are different?
Consider the sample query
```sql
SELECT * FROM (
SELECT k, COUNT(DISTINCT v), SUM(v)
FROM t_asj_18 GROUP BY k
) a LEFT JOIN (
SELECT k, COUNT(v)
FROM t_asj_18 GROUP BY k
) b ON a.k = b.k;
```
In this query the aggregation `k, count(distinct v).. group by k` leads to
group by and hence following RS operator's keys to be `k, v` while keeping
partition column `k`, as we are aggregating on `k`. In such cases where key
columns and partition columns differ, the `UNIFORM` trait is removed [refer
commit](https://github.com/apache/hive/commit/d0acc5d309bba3bb4e6110f92d10e1ea247edd7e).
Note that the group by keys and partition columns differ only with
`distinct` aggregate, removing that would lead to both being `a` thereby having
`UNIFORM` trait.
--
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: gitbox-unsubscr...@hive.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: gitbox-unsubscr...@hive.apache.org
For additional commands, e-mail: gitbox-h...@hive.apache.org
