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From Fabian Hueske <fhue...@apache.org>
Subject Re: [stratosphere-dev] Grouping by a tuple
Date Thu, 12 Jun 2014 08:15:02 GMT
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 <vyacheslav.zholudev@gmail.com
>:

> 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.
>
>
>
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