Copying tuples should be possible. I will open a JIRA for that. Regarding the grouping on multiple fields. A temporary workaround would be to write a MapFunction which extracts the key fields into a Tuple4<POJO, KEY1, KEY2, KEY3> and group on fields 1, 2, 3. This is btw also very similar of is done under the hood when using a KeySelector. Once the Java API was extended to work with named fields of POJOs we don't even need KeySelector functions for this...
2014-06-12 9:53 GMT+02:00 Vyacheslav Zholudev <[email protected] >: > Thanks Robert and Fabian, > >I think the issue is rather grouping a DataSet of custom types on > multiple > fields than grouping a Tuple DataSet > > Yes, that's what I meant. > > Btw, would it be possible to generate a copy method for tuples as well? > Copying e.g. Tuple15 could be quite tedious in the code, but essentially > it's just another object creation. > > > > -- > View this message in context: > http://apache-flink-incubator-mailing-list-archive.1008284.n3.nabble.com/Fwd-stratosphere-dev-Grouping-by-a-tuple-tp40p54.html > Sent from the Apache Flink (Incubator) Mailing List archive. mailing list > archive at Nabble.com. >
