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ASF GitHub Bot commented on FLINK-3702: --------------------------------------- Github user ggevay commented on the issue: https://github.com/apache/flink/pull/2094 > As for this pull request I suggest to update the false Javadoc from the streaming API and document in the concepts that the aggregation field accessors and the keyselectors are slightly different due to there semantics. I've fixed the javadoc now in 154352ba879350bb1ab10b799456a67eb5819375. As for the differences between the key selectors and aggregations (which use `FieldAccessor`): I tried to consolidate the supported field expressions between the two in 7c2dceeb87b06963cc2618312f5f1039387003ad. Now the aggregations should accept any field expression that selects a single field and would be a valid key selector, and some more (selecting array elements). As for documenting that the aggregations don't work on a field that is still some composite type, I'm not sure if this is necessary, since this should be pretty obvious to the user. > The batch API aggregations do not have the overloaded version where you could pass a field accessor string. Here is the Jira for this: https://issues.apache.org/jira/browse/FLINK-4575 > DataStream API PojoFieldAccessor doesn't support nested POJOs > ------------------------------------------------------------- > > Key: FLINK-3702 > URL: https://issues.apache.org/jira/browse/FLINK-3702 > Project: Flink > Issue Type: Improvement > Components: DataStream API > Affects Versions: 1.0.0 > Reporter: Robert Metzger > Assignee: Gabor Gevay > > The {{PojoFieldAccessor}} (which is used by {{.sum(String)}} and similar > methods) doesn't support nested POJOs right now. > As part of FLINK-3697 I'll add a check for a nested POJO and fail with an > exception. -- This message was sent by Atlassian JIRA (v6.3.4#6332)