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[SPARK-25368][SQL] Incorrect predicate pushdown returns wrong result

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## What changes were proposed in this pull request?
How to reproduce:
```scala
val df1 = spark.createDataFrame(Seq(
   (1, 1)
)).toDF("a", "b").withColumn("c", lit(null).cast("int"))
val df2 = df1.union(df1).withColumn("d", spark_partition_id).filter($"c".isNotNull)
df2.show

+---+---+----+---+
|  a|  b|   c|  d|
+---+---+----+---+
|  1|  1|null|  0|
|  1|  1|null|  1|
+---+---+----+---+
```
`filter($"c".isNotNull)` was transformed to `(null <=> c#10)` before https://github.com/apache/spark/pull/19201, but it is transformed to `(c#10 = null)` since https://github.com/apache/spark/pull/20155. This pr revert it to `(null <=> c#10)` to fix this issue.

## How was this patch tested?

unit tests

Closes #22368 from wangyum/SPARK-25368.

Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
This commit is contained in:
Yuming Wang 2018-09-09 09:07:31 -07:00 committed by gatorsmile
parent 88a930dfab
commit 77c996403d
3 changed files with 19 additions and 2 deletions
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2
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LogicalPlan.scala
View file

@ -159,7 +159,7 @@ abstract class UnaryNode extends LogicalPlan {
var allConstraints = child.constraints.asInstanceOf[Set[Expression]]
projectList.foreach {
case a @ Alias(l: Literal, _) =>
allConstraints += EqualTo(a.toAttribute, l)
allConstraints += EqualNullSafe(a.toAttribute, l)
case a @ Alias(e, _) =>
// For every alias in `projectList`, replace the reference in constraints by its attribute.
allConstraints ++= allConstraints.map(_ transform {

2
sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/InferFiltersFromConstraintsSuite.scala
View file

@ -196,7 +196,7 @@ class InferFiltersFromConstraintsSuite extends PlanTest {
test("constraints should be inferred from aliased literals") {
val originalLeft = testRelation.subquery('left).as("left")
val optimizedLeft = testRelation.subquery('left).where(IsNotNull('a) && 'a === 2).as("left")
val optimizedLeft = testRelation.subquery('left).where(IsNotNull('a) && 'a <=> 2).as("left")
val right = Project(Seq(Literal(2).as("two")), testRelation.subquery('right)).as("right")
val condition = Some("left.a".attr === "right.two".attr)

17
sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala
View file

@ -2552,4 +2552,21 @@ class DataFrameSuite extends QueryTest with SharedSQLContext {
}
}
test("SPARK-25368 Incorrect predicate pushdown returns wrong result") {
def check(newCol: Column, filter: Column, result: Seq[Row]): Unit = {
val df1 = spark.createDataFrame(Seq(
(1, 1)
)).toDF("a", "b").withColumn("c", newCol)
val df2 = df1.union(df1).withColumn("d", spark_partition_id).filter(filter)
checkAnswer(df2, result)
}
check(lit(null).cast("int"), $"c".isNull, Seq(Row(1, 1, null, 0), Row(1, 1, null, 1)))
check(lit(null).cast("int"), $"c".isNotNull, Seq())
check(lit(2).cast("int"), $"c".isNull, Seq())
check(lit(2).cast("int"), $"c".isNotNull, Seq(Row(1, 1, 2, 0), Row(1, 1, 2, 1)))
check(lit(2).cast("int"), $"c" === 2, Seq(Row(1, 1, 2, 0), Row(1, 1, 2, 1)))
check(lit(2).cast("int"), $"c" =!= 2, Seq())
}
}