[SPARK-7937][SQL] Support comparison on StructType

This brings #6519 up-to-date with master branch.

Closes #6519.

Author: Liang-Chi Hsieh <viirya@appier.com>
Author: Liang-Chi Hsieh <viirya@gmail.com>
Author: Reynold Xin <rxin@databricks.com>

Closes #7877 from rxin/sort-struct and squashes the following commits:

4968231 [Reynold Xin] Minor fixes.
2537813 [Reynold Xin] Merge branch 'compare_named_struct' of github.com:viirya/spark-1 into sort-struct
d2ba8ad [Liang-Chi Hsieh] Remove unused import.
3a3f40e [Liang-Chi Hsieh] Don't need to add compare to InternalRow because we can use RowOrdering.
dae6aad [Liang-Chi Hsieh] Fix nested struct.
d5349c7 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into compare_named_struct
43d4354 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into compare_named_struct
1f66196 [Liang-Chi Hsieh] Reuse RowOrdering and GenerateOrdering.
f8b2e9c [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into compare_named_struct
1187a65 [Liang-Chi Hsieh] Fix scala style.
9d67f68 [Liang-Chi Hsieh] Fix wrongly merging.
8f4d775 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into compare_named_struct
94b27d5 [Liang-Chi Hsieh] Remove test for error on complex type comparison.
2071693 [Liang-Chi Hsieh] Merge remote-tracking branch 'upstream/master' into compare_named_struct
3c142e4 [Liang-Chi Hsieh] Fix scala style.
cf58dc3 [Liang-Chi Hsieh] Use checkAnswer.
f651b8d [Liang-Chi Hsieh] Remove Either and move orderings to BinaryComparison to reuse it.
b6e1009 [Liang-Chi Hsieh] Fix scala style.
3922b54 [Liang-Chi Hsieh] Support ordering on named_struct.

1 files changed, 42 insertions, 1 deletions

diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveUDFSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveUDFSuite.scala
index 1bde5922b5..7069afc9f7 100644
--- a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveUDFSuite.scala
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/HiveUDFSuite.scala
@@ -28,7 +28,7 @@ import org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectIn
 import org.apache.hadoop.hive.serde2.objectinspector.{ObjectInspector, ObjectInspectorFactory}
 import org.apache.hadoop.hive.serde2.{AbstractSerDe, SerDeStats}
 import org.apache.hadoop.io.Writable
-import org.apache.spark.sql.{AnalysisException, QueryTest, Row}
+import org.apache.spark.sql.{AnalysisException, QueryTest, Row, SQLConf}
 import org.apache.spark.sql.hive.test.TestHive
 
 import org.apache.spark.util.Utils
@@ -93,6 +93,47 @@ class HiveUDFSuite extends QueryTest {
     sql("DROP TEMPORARY FUNCTION IF EXISTS testUDF")
   }
 
+  test("Max/Min on named_struct") {
+    def testOrderInStruct(): Unit = {
+      checkAnswer(sql(
+        """
+          |SELECT max(named_struct(
+          |           "key", key,
+          |           "value", value)).value FROM src
+        """.stripMargin), Seq(Row("val_498")))
+      checkAnswer(sql(
+        """
+          |SELECT min(named_struct(
+          |           "key", key,
+          |           "value", value)).value FROM src
+        """.stripMargin), Seq(Row("val_0")))
+
+      // nested struct cases
+      checkAnswer(sql(
+        """
+          |SELECT max(named_struct(
+          |           "key", named_struct(
+                              "key", key,
+                              "value", value),
+          |           "value", value)).value FROM src
+        """.stripMargin), Seq(Row("val_498")))
+      checkAnswer(sql(
+        """
+          |SELECT min(named_struct(
+          |           "key", named_struct(
+                             "key", key,
+                             "value", value),
+          |           "value", value)).value FROM src
+        """.stripMargin), Seq(Row("val_0")))
+    }
+    val codegenDefault = TestHive.getConf(SQLConf.CODEGEN_ENABLED)
+    TestHive.setConf(SQLConf.CODEGEN_ENABLED, true)
+    testOrderInStruct()
+    TestHive.setConf(SQLConf.CODEGEN_ENABLED, false)
+    testOrderInStruct()
+    TestHive.setConf(SQLConf.CODEGEN_ENABLED, codegenDefault)
+  }
+
   test("SPARK-6409 UDAFAverage test") {
     sql(s"CREATE TEMPORARY FUNCTION test_avg AS '${classOf[GenericUDAFAverage].getName}'")
     checkAnswer(