[
https://issues.apache.org/jira/browse/FLINK-3943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15355944#comment-15355944
]
ASF GitHub Bot commented on FLINK-3943:
---------------------------------------
Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/2169#discussion_r69043528
--- Diff: flink-java/src/main/java/org/apache/flink/api/java/DataSet.java
---
@@ -1193,21 +1196,46 @@ public long count() throws Exception {
operation.setInput(this);
return operation.createResult();
}
-
+
//
--------------------------------------------------------------------------------------------
// Union
//
--------------------------------------------------------------------------------------------
/**
* Creates a union of this DataSet with an other DataSet. The other
DataSet must be of the same data type.
- *
+ *
* @param other The other DataSet which is unioned with the current
DataSet.
* @return The resulting DataSet.
*/
public UnionOperator<T> union(DataSet<T> other){
return new UnionOperator<>(this, other,
Utils.getCallLocationName());
}
+ /**
+ * Creates a set minus of this DataSet with an other DataSet. The other
DataSet must be of the same data type.
+ *
+ * @param other The other DataSet which is set minus with the current
DataSet.
+ * @return The resulting DataSet.
+ */
+ public CoGroupOperator<T, T, T> minus(DataSet<T> other){
--- End diff --
This issue is about adding `EXCEPT` to the Table. The DataSet API which is
touched here is a rather low level API and we are quite careful about adding
new operators. Therefore, changes to the DataSet API should go through a
separate JIRA issue. Please move this code to `DataSetMinus` class and revert
the changes to this file. You can open a JIRA issue to discuss adding a `minus`
operator to the DataSet API. Thank you.
> Add support for EXCEPT (set minus)
> ----------------------------------
>
> Key: FLINK-3943
> URL: https://issues.apache.org/jira/browse/FLINK-3943
> Project: Flink
> Issue Type: New Feature
> Components: Table API & SQL
> Affects Versions: 1.1.0
> Reporter: Fabian Hueske
> Assignee: Ivan Mushketyk
> Priority: Minor
>
> Currently, the Table API and SQL do not support EXCEPT.
> EXCEPT can be executed as a coGroup on all fields that forwards records of
> the first input if the second input is empty.
> In order to add support for EXCEPT to the Table API and SQL we need to:
> - Implement a {{DataSetMinus}} class that translates an EXCEPT into a DataSet
> API program using a coGroup on all fields.
> - Implement a {{DataSetMinusRule}} that translates a Calcite {{LogicalMinus}}
> into a {{DataSetMinus}}.
> - Extend the Table API (and validation phase) to provide an except() method.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
