[HIVE-3655] Use ChainMapper and ChainReducer for queries having [Map+][RMap*] pattern

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: Query Processor
• Assignee: Unassigned
• Reporter: Amareshwari Sriramadasu
• Created: 02/Nov/12 11:37
• Updated: 04/Mar/13 04:16
• Resolved: 04/Mar/13 04:16

Description

While breaking the query plan into multiple map reduce tasks, Hive should consider the pattern [Map+][ReduceMap*] and generate single map reduce job for such patterns using ChainMapper and ChainReducer