[SPARK-23389] When the shuffle dependency specifies aggregation ,and `dependency.mapSideCombine=false`, we should be able to use serialized sorting.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 2.4.0
• Component/s: Spark Core
• Assignee: liuxian
• Reporter: liuxian
• Created: 12/Feb/18 01:27
• Updated: 01/Mar/18 06:29
• Resolved: 01/Mar/18 06:29

Description

When the shuffle dependency specifies aggregation ,and `dependency.mapSideCombine=false`, in the map side,there is no need for aggregation and sorting, so we should be able to use serialized sorting.

Issue Links

• links to: [Github] Pull Request #20576 (10110346)