[
https://issues.apache.org/jira/browse/SPARK-10199?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14721907#comment-14721907
]
Feynman Liang commented on SPARK-10199:
---------------------------------------
[~vinodkc] Thanks! I think these results are convincing. Let's see what others
think but FWIW I'm all for these changes, particularly because it sets
precedence for future model save/load to explicitly specify the schema.
> Avoid using reflections for parquet model save
> ----------------------------------------------
>
> Key: SPARK-10199
> URL: https://issues.apache.org/jira/browse/SPARK-10199
> Project: Spark
> Issue Type: Improvement
> Components: ML, MLlib
> Reporter: Feynman Liang
> Priority: Minor
>
> These items are not high priority since the overhead writing to Parquest is
> much greater than for runtime reflections.
> Multiple model save/load in MLlib use case classes to infer a schema for the
> data frame saved to Parquet. However, inferring a schema from case classes or
> tuples uses [runtime
> reflection|https://github.com/apache/spark/blob/d7b4c095271c36fcc7f9ded267ecf5ec66fac803/sql/core/src/main/scala/org/apache/spark/sql/SQLContext.scala#L361]
> which is unnecessary since the types are already known at the time `save` is
> called.
> It would be better to just specify the schema for the data frame directly
> using {{sqlContext.createDataFrame(dataRDD, schema)}}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org
