[TAJO-1352] Improve the join order algorithm to consider missed cases of associative join operators

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.11.0
• Component/s: Planner/Optimizer
• Assignee: Jihoon Son
• Reporter: Jihoon Son
• Created: 16/Feb/15 12:14
• Updated: 20/Jul/15 11:34
• Resolved: 20/Jul/15 06:31

Description

TAJO-1277 fixes a bug related to the associativity of join operators, but there are still some missed cases that join operators are associative. This work should include the cases described in the following links:

• http://stackoverflow.com/questions/20022196/are-left-outer-joins-associative
• https://cwiki.apache.org/confluence/display/Hive/LanguageManual+Joins

Issue Links

• is blocked by: TAJO-1553 Improve broadcast join planning
• is required by: TAJO-1683 Improve join order optimization of a query involving multiple commutative joins and non-commutative joins
• relates to: TAJO-1310 Maintaining join filters in join operators
• relates to: TAJO-1577 Add test cases to verify join plans