[TAJO-838] Improve query planner to utilize index

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Component/s: Planner/Optimizer
• Assignee: Jihoon Son
• Reporter: Jihoon Son
• Created: 21/May/14 04:57
• Updated: 12/Jan/15 04:39
• Resolved: 08/Jan/15 16:15

Description

Index can improve the query performance when the selectivity of query is high.
Thus, query planner should decide whether index is used or not for a given query.
The selectivity can be guessed using statistics.