[TAJO-1983] Improve memory usage of ExternalSortExec

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.0, 0.10.0, 0.11.0
• Fix Version/s: 0.12.0, 0.11.1
• Component/s: Offheap, Physical Operator
• Assignee: Jinho Kim
• Reporter: Jinho Kim
• Created: 19/Nov/15 09:22
• Updated: 26/Nov/15 05:58
• Resolved: 26/Nov/15 03:05

Description

ExternalSortExec keeps tuple list for sort. but it causes too many GC.
We should change to off-heap tuple instead of VTuple