[ 
https://issues.apache.org/jira/browse/SPARK-15719?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Apache Spark reassigned SPARK-15719:
------------------------------------

    Assignee: Apache Spark  (was: Cheng Lian)

> Disable writing Parquet summary files by default
> ------------------------------------------------
>
>                 Key: SPARK-15719
>                 URL: https://issues.apache.org/jira/browse/SPARK-15719
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 2.0.0
>            Reporter: Cheng Lian
>            Assignee: Apache Spark
>
> Parquet summary files are not particular useful nowadays since
> # when schema merging is disabled, we assume schema of all Parquet part-files 
> are identical, thus we can read the footer from any part-files.
> # when schema merging is enabled, we need to read footers of all files anyway 
> to do the merge.
> On the other hand, writing summary files can be expensive because footers of 
> all part-files must be read and merged. This is particularly costly when 
> appending small dataset to large existing Parquet dataset.



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

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to