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https://issues.apache.org/jira/browse/SPARK-4690?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14233124#comment-14233124
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Sean Owen commented on SPARK-4690:
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No, it is using quadratic probing. It adds {{delta}} each time, but {{delta}}
grows by 1 each time too. The offsets are thus 1, 3, 6, 10 ... or the sequence
n*(n+1)/2 which is quadratic.
> AppendOnlyMap seems not using Quadratic probing as the JavaDoc
> --------------------------------------------------------------
>
> Key: SPARK-4690
> URL: https://issues.apache.org/jira/browse/SPARK-4690
> Project: Spark
> Issue Type: Question
> Components: Spark Core
> Affects Versions: 1.1.0, 1.2.0, 1.3.0
> Reporter: Yijie Shen
> Priority: Minor
>
> org.apache.spark.util.collection.AppendOnlyMap's Documentation like this:
> "This implementation uses quadratic probing with a power-of-2 ...."
> However, the probe procedure in face with a hash collision is just using
> linear probing. the code below:
> val delta = i
> pos = (pos + delta) & mask
> i += 1
> Maybe a bug here?
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