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https://issues.apache.org/jira/browse/IMPALA-10229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17210503#comment-17210503
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Aman Sinha commented on IMPALA-10229:
-------------------------------------

Good catch !  I should have caught it during testing but it looks like the test 
results for the test with no filter condition is likely wrong. The prefix 
checking needs to be done for the outer order-by columns.  

> Analytic limit pushdown optimization can be applied incorrect when there are 
> no analytic predicates
> ---------------------------------------------------------------------------------------------------
>
>                 Key: IMPALA-10229
>                 URL: https://issues.apache.org/jira/browse/IMPALA-10229
>             Project: IMPALA
>          Issue Type: Bug
>          Components: Frontend
>            Reporter: Tim Armstrong
>            Assignee: Tim Armstrong
>            Priority: Blocker
>              Labels: correctness
>
> {noformat}
> [localhost.EXAMPLE.COM:21050] default> select * from (select month, id, 
> rank() over (partition by month order by id desc) rnk from 
> functional_parquet.alltypes WHERE month >= 11) v order by month, id limit 3;
> +-------+------+-----+
> | month | id   | rnk |
> +-------+------+-----+
> | 11    | 6987 | 3   |
> | 11    | 6988 | 2   |
> | 11    | 6989 | 1   |
> +-------+------+-----+
> Fetched 3 row(s) in 4.16s
> {noformat}
> These are not the top 3 rows when ordering by month, id . Hive's result is 
> correct:
> {noformat}
> +----------+-------+--------+
> | v.month  | v.id  | v.rnk  |
> +----------+-------+--------+
> | 11       | 3040  | 600    |
> | 11       | 3041  | 599    |
> | 11       | 3042  | 598    |
> +----------+-------+--------+
> {noformat}
> I think when there's no select predicates, that the ordering in the analytic 
> sort needs to exactly match the TOP N sort ordering. I'm not sure if there 
> are fixes needed for the case where there are select predicates.



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