[FLINK-553] Add getGroupKey() method to group-at-time operators

• Type: Improvement
• Status: Open
• Priority: Not a Priority
• Resolution: Unresolved
• Component/s: API / DataSet
• Labels: auto-deprioritized-major auto-deprioritized-minor github-import
• Assignee: Unassigned
• Reporter: GitHub Import
• Created: 09/Jun/14 12:31
• Updated: 10/Feb/22 22:36

Description

Group-at-a-time operators (Reduce & CoGroup) work on multiple records in one UDF call. Often these UDFs need to access the key that is common to all records of a group.

We could add a function to set a the key of a group before the UDF is called (``setGroupKey()``) and a function to get the key (``getGroupKey()``) that can be called from the UDF.

What do you think about this?

---------------- Imported from GitHub ----------------
Url: https://github.com/stratosphere/stratosphere/issues/553
Created by: fhueske
Labels: enhancement, java api, scala api, user satisfaction,
Assignee: aalexandrov
Created at: Mon Mar 10 22:28:27 CET 2014
State: open