[jira] [Comment Edited] (SPARK-8997) Improve LocalPrefixSpan performance

["Feynman Liang (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SPARK-8997?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14623292#comment-14623292 ] 

Feynman Liang edited comment on SPARK-8997 at 7/11/15 7:40 AM:
---------------------------------------------------------------

Why PrimitiveKeyOpenHashMap if keys will be Array[Int] (and later Array[Array[Item]]), which are not primitive and will not benefit from @specialized annotations?

I'm also not clear on what is meant by 3; aren't list and array both eager (did you mean to use a Stream)? Which part of the code exactly are you referring to?


was (Author: fliang):
Why PrimitiveKeyOpenHashMap if keys will be Array[Int] (and later Array[Array[Item]]), which are not primitive and will not benefit from @specialized annotations?

> Improve LocalPrefixSpan performance
> -----------------------------------
>
>                 Key: SPARK-8997
>                 URL: https://issues.apache.org/jira/browse/SPARK-8997
>             Project: Spark
>          Issue Type: Improvement
>          Components: MLlib
>    Affects Versions: 1.5.0
>            Reporter: Xiangrui Meng
>            Assignee: Feynman Liang
>   Original Estimate: 24h
>  Remaining Estimate: 24h
>
> We can improve the performance by:
> 1. run should output Iterator instead of Array
> 2. Local count shouldn't use groupBy, which creates too many arrays. We can use PrimitiveKeyOpenHashMap
> 3. We can use list to avoid materialize frequent sequences



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org