From 485c61cadd3bf0c8c55043846838d5f36eba5a61 Mon Sep 17 00:00:00 2001
From: Zhongshuai Pei <799203320@qq.com>
Date: Wed, 29 Apr 2015 17:16:18 +0800
Subject: [PATCH 1/3] Update Optimizer.scala

---
 .../org/apache/spark/sql/catalyst/optimizer/Optimizer.scala    | 3 +++
 1 file changed, 3 insertions(+)

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 2d03fbfb0d311..07f0802529127 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
@@ -171,6 +171,9 @@ object ColumnPruning extends Rule[LogicalPlan] {
 
       Project(substitutedProjection, child)
 
+    case Project(projectList, Limit(exp, child)) =>
+      Limit(exp, Project(projectList, child))
+      
     // Eliminate no-op Projects
     case Project(projectList, child) if child.output == projectList => child
   }

From dc83ae9dcb4df19959fe9add34c08203b05ed7b0 Mon Sep 17 00:00:00 2001
From: Zhongshuai Pei <799203320@qq.com>
Date: Thu, 30 Apr 2015 09:27:08 +0800
Subject: [PATCH 2/3] Update FilterPushdownSuite.scala

---
 .../catalyst/optimizer/FilterPushdownSuite.scala | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala
index aa9708b164efa..3c7131c495071 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala
@@ -90,7 +90,23 @@ class FilterPushdownSuite extends PlanTest {
 
     comparePlans(optimized, correctAnswer)
   }
+  
+  test("column pruning for Project(ne, Limit)") {
+    val originalQuery =
+      testRelation
+        .select('a,'b)
+        .limit(2)
+        .select('a)
 
+    val optimized = Optimize(originalQuery.analyze)
+    val correctAnswer =
+      testRelation
+        .select('a)
+        .limit(2).analyze
+
+    comparePlans(optimized, correctAnswer)
+  }
+  
   // After this line is unimplemented.
   test("simple push down") {
     val originalQuery =

From 70d0fca415a6041b7ba39f4e8af01fa1147a551a Mon Sep 17 00:00:00 2001
From: Zhongshuai Pei <799203320@qq.com>
Date: Thu, 30 Apr 2015 10:13:52 +0800
Subject: [PATCH 3/3] Update FilterPushdownSuite.scala

---
 .../spark/sql/catalyst/optimizer/FilterPushdownSuite.scala      | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala
index 3c7131c495071..2ad73941ab978 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FilterPushdownSuite.scala
@@ -98,7 +98,7 @@ class FilterPushdownSuite extends PlanTest {
         .limit(2)
         .select('a)
 
-    val optimized = Optimize(originalQuery.analyze)
+    val optimized = Optimize.execute(originalQuery.analyze)
     val correctAnswer =
       testRelation
         .select('a)