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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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Ian Robertson updated HIVE-5839:
--------------------------------
Description:
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.
was:
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.
> 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: 0.11.0
> Reporter: Ian Robertson
>
> 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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