[
https://issues.apache.org/jira/browse/FLINK-1293?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14248209#comment-14248209
]
ASF GitHub Bot commented on FLINK-1293:
---------------------------------------
Github user he-sk commented on the pull request:
https://github.com/apache/incubator-flink/pull/243#issuecomment-67155467
I think it would work. I just checked that a Java enum (i.e., the old
`Aggregations` class) can contain static methods and you can import them static
and call them just like there were defined in a normal class. I think that the
`Aggregations` class and possibly the old `AggregateOperator` are the only
user-facing classes. The different `AggregationFunction`s and the
`AggregationFunctionFactory` are only used internally and could be moved.
> Add support for out-of-place aggregations
> -----------------------------------------
>
> Key: FLINK-1293
> URL: https://issues.apache.org/jira/browse/FLINK-1293
> Project: Flink
> Issue Type: Improvement
> Components: Java API, Scala API
> Affects Versions: 0.7.0-incubating
> Reporter: Viktor Rosenfeld
> Assignee: Viktor Rosenfeld
> Priority: Minor
>
> Currently, the output of an aggregation is of the same type as the input.
> This restriction has to major drawbacks:
> 1. Every tuple field can only be used in one aggregation because the
> aggregations result is stored in the field.
> 2. Aggregations having a return type that is different from the input type,
> e.g., count or average, cannot be implemented.
> It would be nice to have the aggregation return any kind of tuple as a
> result, so the restrictions above no longer apply.
> See also:
> -
> https://github.com/stratosphere/stratosphere/wiki/Design-of-Aggregate-Operator
> -
> http://apache-flink-incubator-mailing-list-archive.1008284.n3.nabble.com/Hi-Aggregation-support-td2311.html
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
