[ 
https://issues.apache.org/jira/browse/SPARK-12449?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15151116#comment-15151116
 ] 

Max Seiden commented on SPARK-12449:
------------------------------------

[~rxin] Given that predicate pushdown via `sources.Filter` is (afaik) a stable 
API, conceivably that model could be extended to support ever richer operations 
(i.e. sources.Expression, sources.Limit, sources.Join, sources.Aggregation). In 
this case, the stable APIs remain a derivative of the Catalyst plans and all 
that needs to change between releases is the compilation from Catalyst => 
Sources. 

cc [~marmbrus] since we talked briefly about this idea in person at Spark Summit

> Pushing down arbitrary logical plans to data sources
> ----------------------------------------------------
>
>                 Key: SPARK-12449
>                 URL: https://issues.apache.org/jira/browse/SPARK-12449
>             Project: Spark
>          Issue Type: Improvement
>          Components: SQL
>            Reporter: Stephan Kessler
>         Attachments: pushingDownLogicalPlans.pdf
>
>
> With the help of the DataSource API we can pull data from external sources 
> for processing. Implementing interfaces such as {{PrunedFilteredScan}} allows 
> to push down filters and projects pruning unnecessary fields and rows 
> directly in the data source.
> However, data sources such as SQL Engines are capable of doing even more 
> preprocessing, e.g., evaluating aggregates. This is beneficial because it 
> would reduce the amount of data transferred from the source to Spark. The 
> existing interfaces do not allow such kind of processing in the source.
> We would propose to add a new interface {{CatalystSource}} that allows to 
> defer the processing of arbitrary logical plans to the data source. We have 
> already shown the details at the Spark Summit 2015 Europe 
> [https://spark-summit.org/eu-2015/events/the-pushdown-of-everything/]
> I will add a design document explaining details. 



--
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

Reply via email to