[ 
https://issues.apache.org/jira/browse/SPARK-17617?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Sean Zhong updated SPARK-17617:
-------------------------------
    Description: 
h2.Problem

Remainder(%) expression returns incorrect result when using expression.eval to 
calculate the result. expression.eval is called in case like constant folding.

{code}
scala> -5083676433652386516D  % 10
res19: Double = -6.0

// Wrong answer with eval!!!
scala> Seq("-5083676433652386516D").toDF.select($"value" % 10).show
|(value % 10)|
+------------+
|         0.0|
+------------+

// Triggers codegen, will  not do constant folding
scala> sc.makeRDD(Seq("-5083676433652386516D")).toDF.select($"value" % 10).show
+------------+
|(value % 10)|
+------------+
|        -6.0|
+------------+
{code}

Behavior of postgres:
{code}
seanzhong=# select -5083676433652386516.0  % 10;
 ?column? 
----------
     -6.0
(1 row)
{code}



  was:
h2.Problem

Remainder(%) expression returns incorrect result when eval is called to do 
constant folding

{code}
scala> -5083676433652386516D  % 10
res19: Double = -6.0

// Wrong answer because of constant folding!!!
scala> Seq("-5083676433652386516D").toDF.select($"value" % 10).show
|(value % 10)|
+------------+
|         0.0|
+------------+

// Triggers codegen, will  not do constant folding
scala> sc.makeRDD(Seq("-5083676433652386516D")).toDF.select($"value" % 10).show
+------------+
|(value % 10)|
+------------+
|        -6.0|
+------------+
{code}

Behavior of postgres:
{code}
seanzhong=# select -5083676433652386516.0  % 10;
 ?column? 
----------
     -6.0
(1 row)
{code}




> Remainder(%) expression.eval returns incorrect result
> -----------------------------------------------------
>
>                 Key: SPARK-17617
>                 URL: https://issues.apache.org/jira/browse/SPARK-17617
>             Project: Spark
>          Issue Type: Bug
>          Components: SQL
>            Reporter: Sean Zhong
>
> h2.Problem
> Remainder(%) expression returns incorrect result when using expression.eval 
> to calculate the result. expression.eval is called in case like constant 
> folding.
> {code}
> scala> -5083676433652386516D  % 10
> res19: Double = -6.0
> // Wrong answer with eval!!!
> scala> Seq("-5083676433652386516D").toDF.select($"value" % 10).show
> |(value % 10)|
> +------------+
> |         0.0|
> +------------+
> // Triggers codegen, will  not do constant folding
> scala> sc.makeRDD(Seq("-5083676433652386516D")).toDF.select($"value" % 
> 10).show
> +------------+
> |(value % 10)|
> +------------+
> |        -6.0|
> +------------+
> {code}
> Behavior of postgres:
> {code}
> seanzhong=# select -5083676433652386516.0  % 10;
>  ?column? 
> ----------
>      -6.0
> (1 row)
> {code}



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