[ https://issues.apache.org/jira/browse/FLINK-3848?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15725765#comment-15725765 ]
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_r91051611 --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/plan/nodes/dataset/BatchTableSourceScan.scala --- @@ -48,6 +57,11 @@ class BatchTableSourceScan( ) } +// override def explainTerms(pw: RelWriter): RelWriter = { --- End diff -- Please add this method > 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)