[jira] [Created] (CALCITE-2605) NullPointerException when left outer join implemented with EnumerableCorrelate

["Ruben Quesada Lopez (JIRA)" <ji...@apache.org>]

Ruben Quesada Lopez created CALCITE-2605:
--------------------------------------------

             Summary: NullPointerException when left outer join implemented with EnumerableCorrelate
                 Key: CALCITE-2605
                 URL: https://issues.apache.org/jira/browse/CALCITE-2605
             Project: Calcite
          Issue Type: Bug
    Affects Versions: 1.17.0
            Reporter: Ruben Quesada Lopez
            Assignee: Julian Hyde
             Fix For: 1.18.0


In the context of a LEFT OUTER JOIN implemented via EnumerableCorrelate, the generated code for the selector does not check if the right object is null (which can be, since it is a LEFT join). This situation can lead to a NullPointerException.

The root cause is located in EnumerableCorrelate::implement method, which builds the selector expression using a ternary operator whose "if" and "else" statements are switched:
{code:java}
    Expression selector =
        EnumUtils.joinSelector(
            joinType.returnsJustFirstInput() ? joinType.toJoinType()
                : JoinRelType.INNER, physType,
            ImmutableList.of(leftResult.physType, rightResult.physType));
{code}
This code works (by coincidence) in the case of an INNER join; but in case of LEFT, it will incorrectly call EnumUtils.joinSelector(...) with JoinRelType.INNER instead of JoinRelType.LEFT, which will produce the problematic generated code. Also, the current code in the context of a SEMI or ANTI join will throw an IllegalStateException when calling SemiJoinType::toJoinType.

If I am not mistaken, to fix this we just need to switch the ternary operator statements:
{code:java}
    Expression selector =
        EnumUtils.joinSelector(
            joinType.returnsJustFirstInput() ? JoinRelType.INNER
                : joinType.toJoinType(), physType,
            ImmutableList.of(leftResult.physType, rightResult.physType));
{code}
 



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)