[SPARK-11733] Allow shuffle readers to request data from just one mapper

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Incomplete
• Component/s: Spark Core, SQL
• Labels: bulk-closed
• Assignee: Unassigned
• Reporter: Matei Alexandru Zaharia
• Created: 13/Nov/15 18:30
• Updated: 21/May/19 04:37
• Resolved: 21/May/19 04:37

Description

This is needed to do broadcast joins. Right now the shuffle reader interface takes a range of reduce IDs but fetches from all maps.