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ASF GitHub Bot commented on FLINK-3080: --------------------------------------- Github user aljoscha commented on the pull request: https://github.com/apache/flink/pull/1425#issuecomment-161041124 Yes, you get each element twice, so it behaves like bag-union. @mxm I added a test case. > Cannot union a data stream with a product of itself > --------------------------------------------------- > > Key: FLINK-3080 > URL: https://issues.apache.org/jira/browse/FLINK-3080 > Project: Flink > Issue Type: Bug > Components: Streaming > Affects Versions: 0.10.0 > Reporter: Vasia Kalavri > Assignee: Aljoscha Krettek > > Currently it is not possible to union a stream with itself or a product of > itself. > For example, the following code > {{stream.union(stream.map(...))}} > fails with this exception: "A DataStream cannot be unioned with itself". > The documentation currently states that "If you union a data stream with > itself you will still only get each element once." and should also be updated. -- This message was sent by Atlassian JIRA (v6.3.4#6332)