flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-3848) Add ProjectableTableSource interface and translation rule
Date Tue, 06 Dec 2016 15:11:59 GMT

    [ https://issues.apache.org/jira/browse/FLINK-3848?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15725768#comment-15725768
] 

ASF GitHub Bot commented on FLINK-3848:
---------------------------------------

Github user fhueske commented on a diff in the pull request:

    https://github.com/apache/flink/pull/2810#discussion_r91077345
  
    --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/sources/CsvTableSource.scala
---
    @@ -51,9 +51,12 @@ class CsvTableSource(
         quoteCharacter: Character = null,
         ignoreFirstLine: Boolean = false,
         ignoreComments: String = null,
    -    lenient: Boolean = false)
    +    lenient: Boolean = false,
    +    private val projectionFieldsMask: Option[Array[Boolean]] = None,
    --- End diff --
    
    the projection should not go into the public constructor of `CsvTableSource`. It should
be hidden from the user, since it is automatically applied for each individual query by the
optimizer.


> Add ProjectableTableSource interface and translation rule
> ---------------------------------------------------------
>
>                 Key: FLINK-3848
>                 URL: https://issues.apache.org/jira/browse/FLINK-3848
>             Project: Flink
>          Issue Type: New Feature
>          Components: Table API & SQL
>            Reporter: Fabian Hueske
>            Assignee: Anton Solovev
>
> Add a {{ProjectableTableSource}} interface for {{TableSource}} implementation that support
projection push-down.
> The interface could look as follows
> {code}
> def trait ProjectableTableSource {
>   def setProjection(fields: Array[String]): Unit
> }
> {code}
> In addition we need Calcite rules to push a projection into a TableScan that refers to
a {{ProjectableTableSource}}. We might need to tweak the cost model as well to push the optimizer
in the right direction.
> Moreover, the {{CsvTableSource}} could be extended to implement {{ProjectableTableSource}}.



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

Mime
View raw message