Github user yhuai commented on the pull request:
https://github.com/apache/spark/pull/3496#issuecomment-69237458
I do not see any total order guarantee is mentioned in
https://cwiki.apache.org/confluence/display/Hive/LanguageManual+SortBy. Here
are what I find...
>Hive uses the columns in Distribute By to distribute the rows among
reducers. All rows with the same Distribute By columns will go to the same
reducer. However, Distribute By does not guarantee clustering or sorting
properties on the distributed keys.
>Cluster By is a short-cut for both Distribute By and Sort By.
>Hive supports SORT BY which sorts the data per reducer.
For a particular case, if total order is guaranteed is based on the
partitioner. The default partitioner is
`org.apache.hadoop.hive.ql.io.DefaultHivePartitioner`
(https://github.com/apache/hive/blob/trunk/ql/src/java/org/apache/hadoop/hive/ql/io/DefaultHivePartitioner.java),
which is a hash partitioner.
I do not think we need to make the change.
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