[jira] [Commented] (SPARK-7478) Add a SQLContext.getOrCreate to maintain a singleton instance of SQLContext

["Tathagata Das (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/SPARK-7478?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14534094#comment-14534094 ] 

Tathagata Das commented on SPARK-7478:
--------------------------------------

[~rxin] Thoughts?

> Add a SQLContext.getOrCreate to maintain a singleton instance of SQLContext
> ---------------------------------------------------------------------------
>
>                 Key: SPARK-7478
>                 URL: https://issues.apache.org/jira/browse/SPARK-7478
>             Project: Spark
>          Issue Type: New Feature
>          Components: SQL
>            Reporter: Tathagata Das
>            Assignee: Tathagata Das
>            Priority: Blocker
>
> Having a SQLContext singleton would make it easier for applications to use a lazily instantiated single shared instance of SQLContext when needed. It would avoid problems like 
> 1. In REPL/notebook environment, rerunning the line {{val sqlContext = new SQLContext}} multiple times created different contexts while overriding the reference to previous context, leading to issues like registered temp tables going missing.
> 2. In Streaming, creating SQLContext directly leads to serialization/deserialization issues when attempting to recover from DStream checkpoints. See [SPARK-6770].
> This can be solved by {{SQLContext.getOrCreate}} which get or creates a new singleton instance of SQLContext using either a given SparkContext or a given SparkConf



--
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