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https://issues.apache.org/jira/browse/HIVE-5839?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Xuefu Zhang updated HIVE-5839:
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Affects Version/s: 0.12.0
Status: Patch Available (was: Open)
The first patch adjusts the behavior, with new tests pending. However, I'd like
to see what the change impacts without knowing the rationale behind the
original implementation. Let's see how the test goes.
> BytesRefArrayWritable compareTo violates contract
> -------------------------------------------------
>
> Key: HIVE-5839
> URL: https://issues.apache.org/jira/browse/HIVE-5839
> Project: Hive
> Issue Type: Bug
> Components: Serializers/Deserializers
> Affects Versions: 0.12.0, 0.11.0
> Reporter: Ian Robertson
> Assignee: Xuefu Zhang
> Attachments: HIVE-5839.patch
>
>
> BytesRefArrayWritable's compareTo violates the compareTo contract from
> java.lang.Object. Specifically:
> * The implementor must ensure sgn(x.compareTo( y )) == -sgn(y.compareTo( x ))
> for all x and y.
> The compareTo implementation on BytesRefArrayWritable does a proper
> comparison of the sizes of the two instances. However, if the sizes are the
> same, it proceeds to do a check if both array's have the same constant. If
> not, it returns 1. This means that if x and y are two BytesRefArrayWritable
> instances with the same size, but different contents, then x.compareTo( y )
> == 1 and y.compareTo( x ) == 1.
> Additionally, the comparison of contents is order agnostic. This seems wrong,
> since order of entries should matter. It is also very inefficient, running at
> O(n^2), where n is the number of entries.
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