[HIVE-1754] Remove JDBM component from Map Join

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.6.0, 0.7.0
• Fix Version/s: 0.7.0
• Component/s: Query Processor
• Assignee: Liyin Tang
• Reporter: Liyin Tang
• Created: 27/Oct/10 01:27
• Updated: 16/Dec/11 23:59
• Resolved: 12/Nov/10 06:50

Description

Right now, JDBM is the major performance bottleneck of performance.
With the growth of the small table, the PUT and GET operation will take most of execution time.

Map Join is designed to load the data of small table into memory.
If the data is too large to hold in memory, then there is no need to use the map join strategy.