[jira] [Created] (DRILL-5408) Disallow changing to a Right Outer Join by flipping the left and right sides during NLJ

["Arina Ielchiieva (JIRA)" <ji...@apache.org>]

Arina Ielchiieva created DRILL-5408:
---------------------------------------

             Summary: Disallow changing to a Right Outer Join by flipping the left and right sides during NLJ
                 Key: DRILL-5408
                 URL: https://issues.apache.org/jira/browse/DRILL-5408
             Project: Apache Drill
          Issue Type: Improvement
    Affects Versions: 1.11.0
            Reporter: Arina Ielchiieva
            Priority: Minor


Nested loop join allows only INNER and LEFT join usage and implies that right input is smaller that left input. During LEFT join when join optimization is enabled and detected that right input is larger that left, join will be optimized: left and right inputs will be flipped and LEFT join type will be changed to RIGHT one. If query contains non-equi joins, after such optimization it will fail, since nested loop does not allow RIGHT join.

DRILL-5375 introduced option JOIN_OPTIMIZATION option which when is disabled won't allow swapping of left and right inputs. Once hash and merge joins will allow non-equi join conditions, the need to turn off join optimization may go away.

This Jira is created to investigate if there is a way to disallow changing to a Right Outer Join by flipping the left and right sides when NLJ is used without disabling JOIN_OPTIMIZATION.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)