[FLINK-11052] Add Bounded(Group Window) FlatAggregate operator to batch Table API

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Table SQL / API
• Labels: auto-unassigned
• Assignee: Unassigned
• Reporter: sunjincheng
• Created: 03/Dec/18 09:05
• Updated: 27/Apr/21 23:11

Description

Add FlatAggregate operator to batch group window Table API as described in FLIP-29.

The usage:

tab.window(Tumble/Session/Slide... as 'w)
   .groupBy('w, 'k1, 'k2)
   .flatAggregate(tableAggregate('a))
   .select('w.rowtime, 'k1, 'k2, 'col1, 'col2)