Hyoungjun Kim created TAJO-853:
----------------------------------
Summary: Refactoring FilterPushDown for OUTER JOIN
Key: TAJO-853
URL: https://issues.apache.org/jira/browse/TAJO-853
Project: Tajo
Issue Type: Improvement
Reporter: Hyoungjun Kim
Assignee: Hyoungjun Kim
Priority: Minor
Currently Tajo doesn't support a filter OUTER JOIN's ON clause.
or has some bugs. There is some rules for this in the following urls.
-
http://www.ibm.com/developerworks/data/library/techarticle/purcell/0112purcell.html
- https://cwiki.apache.org/confluence/display/Hive/OuterJoinBehavior
Briefly summarized as follows.
- Join Predicate on Preserved Row Table: Used for join condition(not filter)
- Join Predicate on Null Supplying Table: Can push down to the table scan
- Where Predicate on Preserved Row Table: Can push down to the table scan
- Where Predicate on Null Supplying Table: Used for filter with join result
data. This filter condition is attached to SELECTION Node.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
