[SPARK-21427] Describe mapGroupsWithState and flatMapGroupsWithState for stateful aggregation in Structured Streaming

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Incomplete
• Affects Version/s: 2.2.0
• Component/s: Documentation, Structured Streaming
• Labels: bulk-closed
• Assignee: Unassigned
• Reporter: Jacek Laskowski
• Shepherd: Shixiong Zhu
• Created: 16/Jul/17 11:26
• Updated: 21/May/19 04:14
• Resolved: 21/May/19 04:14

Description

1. Rename "Arbitrary Stateful Operations" to "Stateful Aggregations" (see https://people.apache.org/~pwendell/spark-nightly/spark-master-docs/latest/structured-streaming-programming-guide.html#arbitrary-stateful-operations for the latest version)
2. Describe two operators mapGroupsWithState and flatMapGroupsWithState with examples.