[
https://issues.apache.org/jira/browse/SPARK-11135?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Michael Armbrust resolved SPARK-11135.
--------------------------------------
Resolution: Fixed
Fix Version/s: 1.5.2
1.6.0
Issue resolved by pull request 9140
[https://github.com/apache/spark/pull/9140]
> Exchange sort-planning logic incorrectly avoid sorts when existing ordering
> is non-empty subset of required ordering
> --------------------------------------------------------------------------------------------------------------------
>
> Key: SPARK-11135
> URL: https://issues.apache.org/jira/browse/SPARK-11135
> Project: Spark
> Issue Type: Bug
> Components: SQL
> Reporter: Josh Rosen
> Assignee: Josh Rosen
> Priority: Blocker
> Fix For: 1.6.0, 1.5.2
>
>
> In Spark SQL, the Exchange planner tries to avoid unnecessary sorts in cases
> where the data has already been sorted by a superset of the requested sorting
> columns. For instance, let's say that a query calls for an operator's input
> to be sorted by `a.asc` and the input happens to already be sorted by
> `[a.asc, b.asc]`. In this case, we do not need to re-sort the input. The
> converse, however, is not true: if the query calls for `[a.asc, b.asc]`, then
> `a.asc` alone will not satisfy the ordering requirements, requiring an
> additional sort to be planned by Exchange.
> However, the current Exchange code gets this wrong and incorrectly skips
> sorting when the existing output ordering is a subset of the required
> ordering. This is simple to fix, however.
> This bug was introduced in https://github.com/apache/spark/pull/7458, so it
> affects 1.5.0+.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
