[HIVE-3133] Implement non-equi mapjoin

• Type: Improvement
• Status: Patch Available
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.10.0
• Component/s: Query Processor, SQL
• Assignee: Navis Ryu
• Reporter: Navis Ryu
• Created: 13/Jun/12 18:32
• Updated: 16/Jul/12 05:57

Description

Currently, hive supports only equi-join which means all joining columns should be related only with equal operator(= or <=>).
It seemed to be not easy to provide non-equi join in general manner but if one of table is small enough to be fit in memory, it might be possible to be implemented rather easily by exploiting current implementation of MapJoin.