[HIVE-1831] Add a option to run task to check map-join possibility in non-local mode

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.7.0
• Component/s: Query Processor
• Hadoop Flags: Reviewed
• Assignee: Liyin Tang
• Reporter: Namit Jain
• Created: 06/Dec/10 07:12
• Updated: 16/Dec/11 23:59
• Resolved: 09/Dec/10 06:14

Description

In HIVE-1642, we run a local task to figure out if the small table can be held in memory, and then convert the join into a map-join.
However, this can be a good idea for thin clients (which may not have enough memory).

This should be made configurable - where the default can still be to run the task locally on the client machine, but an option
should be added for thin clients, where the task would be run as a map-only task