[jira] [Created] (DRILL-665) Drill throw NPE or UnsupportedOperationException when case expression contains null value

["Jinfeng Ni (JIRA)" <ji...@apache.org>]

Jinfeng Ni created DRILL-665:
--------------------------------

             Summary: Drill throw NPE or UnsupportedOperationException when case expression contains null value
                 Key: DRILL-665
                 URL: https://issues.apache.org/jira/browse/DRILL-665
             Project: Apache Drill
          Issue Type: Bug
            Reporter: Jinfeng Ni
            Assignee: Timothy Chen


Hi Tim,

Per discussion yesterday,  we found Drill will throw NPE or UnsupportedOperationException when case expression contains null value.  (null value is added for the optional 'else' branch).  

Q1:

select case when n_nationkey < 100 then 100 end from cp.`tpch/nation.parquet`;

java.lang.NullPointerException
	org.apache.drill.exec.planner.logical.DrillOptiq$RexToDrill.visitLiteral(DrillOptiq.java:330) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
......

Q2.

select case when n_nationkey < 100 then n_name end from cp.`tpch/nation.parquet`;

java.lang.UnsupportedOperationException: Unable to convert the value of null and type NULL to a Drill constant expression.
	org.apache.drill.exec.planner.logical.DrillOptiq$RexToDrill.visitLiteral(DrillOptiq.java:367) ~[drill-java-exec-1.0.0-m2-incubating-SNAPSHOT-rebuffed.jar:1.0.0-m2-incubating-SNAPSHOT]
......

Our conclusion is Drill need create proper TypedNullConstant in DrillOptiq when the null value is associated with regular SQL type, or resolve to proper SQL typed null constant, in IExpressionTreeMaterializer.visitIfExpression. ( case/if expression requires all the branches return the type of value).




--
This message was sent by Atlassian JIRA
(v6.2#6252)