[SPARK-10463] [SQL] remove PromotePrecision during optimization

PromotePrecision is not necessary after HiveTypeCoercion done.

Jira:
https://issues.apache.org/jira/browse/SPARK-10463

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #8621 from adrian-wang/promoterm.

1 files changed, 4 insertions, 3 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala
index 63602eaa8c..6557c7005d 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/Optimizer.scala
@@ -57,7 +57,7 @@ object DefaultOptimizer extends Optimizer {
       ConstantFolding,
       LikeSimplification,
       BooleanSimplification,
-      RemovePositive,
+      RemoveDispensable,
       SimplifyFilters,
       SimplifyCasts,
       SimplifyCaseConversionExpressions) ::
@@ -784,11 +784,12 @@ object SimplifyCasts extends Rule[LogicalPlan] {
 }
 
 /**
- * Removes [[UnaryPositive]] identify function
+ * Removes nodes that are not necessary.
  */
-object RemovePositive extends Rule[LogicalPlan] {
+object RemoveDispensable extends Rule[LogicalPlan] {
   def apply(plan: LogicalPlan): LogicalPlan = plan transformAllExpressions {
     case UnaryPositive(child) => child
+    case PromotePrecision(child) => child
   }
 }