From 9de836ece3800af0cecf29b130d3ef50471c130a Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Tue, 24 Mar 2020 21:26:24 +0800
Subject: [PATCH 01/10] [SPARK-31234][SQL] ResetCommand should reset config to
 sc.conf only

---
 .../apache/spark/sql/internal/SQLConf.scala   |  2 ++
 .../sql/execution/command/SetCommand.scala    |  6 +++++-
 .../spark/sql/internal/SQLConfSuite.scala     | 20 +++++++++----------
 .../spark/sql/test/SharedSparkSession.scala   |  1 +
 4 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
index 9a524defb281..4c567dcae82a 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
@@ -3258,7 +3258,9 @@ class SQLConf extends Serializable with Logging {
   }
 
   def clear(): Unit = {
+    val reserved = settings.asScala.filterKeys(staticConfKeys.contains).toMap
     settings.clear()
+    settings.putAll(reserved.asJava)
   }
 
   override def clone(): SQLConf = {
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
index c55ff4ffefa0..8066f8402134 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
@@ -170,7 +170,11 @@ object SetCommand {
 case object ResetCommand extends RunnableCommand with IgnoreCachedData {
 
   override def run(sparkSession: SparkSession): Seq[Row] = {
-    sparkSession.sessionState.conf.clear()
+    val conf = sparkSession.sessionState.conf
+    conf.clear()
+    sparkSession.sparkContext.conf.getAll.foreach { case (k, v) =>
+      conf.setConfString(k, v)
+    }
     Seq.empty[Row]
   }
 }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index 650dc127a060..ec09a3f332cc 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -32,20 +32,13 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
   private val testKey = "test.key.0"
   private val testVal = "test.val.0"
 
-  test("propagate from spark conf") {
-    // We create a new context here to avoid order dependence with other tests that might call
-    // clear().
-    val newContext = new SQLContext(SparkSession.builder().sparkContext(sparkContext).getOrCreate())
-    assert(newContext.getConf("spark.sql.testkey", "false") === "true")
-  }
-
   test("programmatic ways of basic setting and getting") {
     // Set a conf first.
     spark.conf.set(testKey, testVal)
     // Clear the conf.
     spark.sessionState.conf.clear()
     // After clear, only overrideConfs used by unit test should be in the SQLConf.
-    assert(spark.conf.getAll === TestSQLContext.overrideConfs)
+    assert((spark.conf.getAll -- TestSQLContext.overrideConfs.keys).size < spark.conf.getAll.size)
 
     spark.conf.set(testKey, testVal)
     assert(spark.conf.get(testKey) === testVal)
@@ -115,6 +108,13 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
     }
   }
 
+  test("reset - static conf") {
+    spark.sessionState.conf.clear()
+    assert(spark.conf.get(StaticSQLConf.UI_RETAINED_EXECUTIONS) === 1)
+    sql(s"reset")
+    assert(spark.conf.get(StaticSQLConf.UI_RETAINED_EXECUTIONS) === 1)
+  }
+
   test("reset - public conf") {
     spark.sessionState.conf.clear()
     val original = spark.conf.get(SQLConf.GROUP_BY_ORDINAL)
@@ -218,8 +218,8 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
   test("default value of WAREHOUSE_PATH") {
     // JVM adds a trailing slash if the directory exists and leaves it as-is, if it doesn't
     // In our comparison, strip trailing slash off of both sides, to account for such cases
-    assert(new Path(Utils.resolveURI("spark-warehouse")).toString.stripSuffix("/") === spark
-      .sessionState.conf.warehousePath.stripSuffix("/"))
+    assert(new Path(Utils.resolveURI(s"spark-warehouse/${classOf[SQLConfSuite].getCanonicalName}"))
+        .toString.stripSuffix("/") === spark.sessionState.conf.warehousePath.stripSuffix("/"))
   }
 
   test("static SQL conf comes from SparkConf") {
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala b/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala
index ee29b4b8fb32..2b81c29df10f 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala
@@ -72,6 +72,7 @@ trait SharedSparkSessionBase
       // this rule may potentially block testing of other optimization rules such as
       // ConstantPropagation etc.
       .set(SQLConf.OPTIMIZER_EXCLUDED_RULES.key, ConvertToLocalRelation.ruleName)
+      .set(StaticSQLConf.UI_RETAINED_EXECUTIONS, 1)
     conf.set(
       StaticSQLConf.WAREHOUSE_PATH,
       conf.get(StaticSQLConf.WAREHOUSE_PATH) + "/" + getClass.getCanonicalName)

From 3b6b3aab3b42d0aff5f8b0b1785164da0a154063 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 00:24:52 +0800
Subject: [PATCH 02/10] nit

---
 .../scala/org/apache/spark/sql/internal/SQLConfSuite.scala | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index ec09a3f332cc..18a22e0ba852 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -32,6 +32,13 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
   private val testKey = "test.key.0"
   private val testVal = "test.val.0"
 
+  test("propagate from spark conf") {
+    // We create a new context here to avoid order dependence with other tests that might call
+    // clear().
+    val newContext = new SQLContext(SparkSession.builder().sparkContext(sparkContext).getOrCreate())
+    assert(newContext.getConf("spark.sql.testkey", "false") === "true")
+  }
+
   test("programmatic ways of basic setting and getting") {
     // Set a conf first.
     spark.conf.set(testKey, testVal)

From 435e4112355a31c158619dd2ca4f05d6d71242f9 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 13:18:57 +0800
Subject: [PATCH 03/10] fix tests

---
 docs/sql-ref-syntax-aux-conf-mgmt-reset.md    |  2 +-
 .../sql/execution/command/SetCommand.scala    |  3 ++-
 .../org/apache/spark/sql/SQLQuerySuite.scala  | 22 +++++++------------
 .../spark/sql/internal/SQLConfSuite.scala     | 16 ++++++++++----
 .../spark/sql/test/SharedSparkSession.scala   |  1 -
 5 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
index 8ee61514ee4e..c1aaafeb1e48 100644
--- a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
+++ b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
@@ -20,7 +20,7 @@ license: |
 ---
 
 ### Description
-Reset all the properties specific to the current session to their default values. After RESET command, executing SET command will output empty.
+Reset any properties specific to the current session which were set via the [SET](sql-ref-syntax-aux-conf-mgmt-set.html) command to their default values.
 
 ### Syntax
 {% highlight sql %}
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
index 8066f8402134..451ddc32b567 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
@@ -162,7 +162,8 @@ object SetCommand {
 }
 
 /**
- * This command is for resetting SQLConf to the default values. Command that runs
+ * This command is for resetting SQLConf to the default values. Any configurations that were set
+ * via [[SetCommand]] will get reset to default value Command that runs
  * {{{
  *   reset;
  * }}}
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index de0f7801a39a..cef066355686 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -1021,36 +1021,30 @@ class SQLQuerySuite extends QueryTest with SharedSparkSession with AdaptiveSpark
   }
 
   test("SET commands semantics using sql()") {
-    spark.sessionState.conf.clear()
     val testKey = "test.key.0"
     val testVal = "test.val.0"
     val nonexistentKey = "nonexistent"
 
     // "set" itself returns all config variables currently specified in SQLConf.
-    assert(sql("SET").collect().size === TestSQLContext.overrideConfs.size)
-    sql("SET").collect().foreach { row =>
-      val key = row.getString(0)
-      val value = row.getString(1)
-      assert(
-        TestSQLContext.overrideConfs.contains(key),
-        s"$key should exist in SQLConf.")
-      assert(
-        TestSQLContext.overrideConfs(key) === value,
-        s"The value of $key should be ${TestSQLContext.overrideConfs(key)} instead of $value.")
+    TestSQLContext.overrideConfs.foreach { case (k, _) =>
+      assert(sql("SET").where(s"key ='$k'").collect().head.get(1) ===
+        TestSQLContext.overrideConfs(k))
+
     }
-    val overrideConfs = sql("SET").collect()
+
+    val originalConfs = sql("SET").collect()
 
     // "set key=val"
     sql(s"SET $testKey=$testVal")
     checkAnswer(
       sql("SET"),
-      overrideConfs ++ Seq(Row(testKey, testVal))
+      originalConfs ++ Seq(Row(testKey, testVal))
     )
 
     sql(s"SET ${testKey + testKey}=${testVal + testVal}")
     checkAnswer(
       sql("set"),
-      overrideConfs ++ Seq(Row(testKey, testVal), Row(testKey + testKey, testVal + testVal))
+      originalConfs ++ Seq(Row(testKey, testVal), Row(testKey + testKey, testVal + testVal))
     )
 
     // "set key"
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index 18a22e0ba852..17d4fcacac8e 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -115,11 +115,19 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
     }
   }
 
-  test("reset - static conf") {
-    spark.sessionState.conf.clear()
-    assert(spark.conf.get(StaticSQLConf.UI_RETAINED_EXECUTIONS) === 1)
+  test("reset - static and spark conf") {
+    val conf = spark.sessionState.conf.getAllConfs
+    val appName = conf.get("spark.app.name")
+    val driverHost = conf.get("spark.driver.host")
+    val master = conf.get("spark.master")
+    val warehouseDir = conf.get("spark.sql.warehouse.dir")
+    // ensure the conf here is not default value, and will not be reset to default value
+    assert(warehouseDir.get.contains(this.getClass.getCanonicalName))
     sql(s"reset")
-    assert(spark.conf.get(StaticSQLConf.UI_RETAINED_EXECUTIONS) === 1)
+    assert(conf.get("spark.app.name") === appName)
+    assert(conf.get("spark.driver.host") === driverHost)
+    assert(conf.get("spark.master") === master)
+    assert(conf.get("spark.sql.warehouse.dir") === warehouseDir)
   }
 
   test("reset - public conf") {
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala b/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala
index 2b81c29df10f..ee29b4b8fb32 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/test/SharedSparkSession.scala
@@ -72,7 +72,6 @@ trait SharedSparkSessionBase
       // this rule may potentially block testing of other optimization rules such as
       // ConstantPropagation etc.
       .set(SQLConf.OPTIMIZER_EXCLUDED_RULES.key, ConvertToLocalRelation.ruleName)
-      .set(StaticSQLConf.UI_RETAINED_EXECUTIONS, 1)
     conf.set(
       StaticSQLConf.WAREHOUSE_PATH,
       conf.get(StaticSQLConf.WAREHOUSE_PATH) + "/" + getClass.getCanonicalName)

From ef636045025beee11d1688be72381f413ca0bb64 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 14:38:22 +0800
Subject: [PATCH 04/10] nnit

---
 docs/sql-ref-syntax-aux-conf-mgmt-reset.md                      | 2 +-
 .../org/apache/spark/sql/execution/command/SetCommand.scala     | 2 +-
 .../src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala     | 1 -
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
index c1aaafeb1e48..34c243d3be9e 100644
--- a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
+++ b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
@@ -20,7 +20,7 @@ license: |
 ---
 
 ### Description
-Reset any properties specific to the current session which were set via the [SET](sql-ref-syntax-aux-conf-mgmt-set.html) command to their default values.
+Reset any runtime properties specific to the current session which were set via the [SET](sql-ref-syntax-aux-conf-mgmt-set.html) command to their default values.
 
 ### Syntax
 {% highlight sql %}
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
index 451ddc32b567..3dc1d5269771 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/SetCommand.scala
@@ -163,7 +163,7 @@ object SetCommand {
 
 /**
  * This command is for resetting SQLConf to the default values. Any configurations that were set
- * via [[SetCommand]] will get reset to default value Command that runs
+ * via [[SetCommand]] will get reset to default value. Command that runs
  * {{{
  *   reset;
  * }}}
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index cef066355686..477f195df311 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -1029,7 +1029,6 @@ class SQLQuerySuite extends QueryTest with SharedSparkSession with AdaptiveSpark
     TestSQLContext.overrideConfs.foreach { case (k, _) =>
       assert(sql("SET").where(s"key ='$k'").collect().head.get(1) ===
         TestSQLContext.overrideConfs(k))
-
     }
 
     val originalConfs = sql("SET").collect()

From bcc678656ae134e5917e244a4fa6662920b662ab Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 14:43:56 +0800
Subject: [PATCH 05/10] nnit

---
 docs/sql-ref-syntax-aux-conf-mgmt-reset.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
index 34c243d3be9e..085f21b638bd 100644
--- a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
+++ b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
@@ -20,7 +20,7 @@ license: |
 ---
 
 ### Description
-Reset any runtime properties specific to the current session which were set via the [SET](sql-ref-syntax-aux-conf-mgmt-set.html) command to their default values.
+Reset any runtime configurations specific to the current session which were set via the [SET](sql-ref-syntax-aux-conf-mgmt-set.html) command to their default values.
 
 ### Syntax
 {% highlight sql %}

From 69a4b82422b53fe4345419615d46782283119bc9 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 18:13:46 +0800
Subject: [PATCH 06/10] address cmts

---
 .../scala/org/apache/spark/sql/internal/SQLConf.scala     | 2 --
 .../org/apache/spark/sql/internal/SQLConfSuite.scala      | 8 ++++----
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
index 4c567dcae82a..9a524defb281 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
@@ -3258,9 +3258,7 @@ class SQLConf extends Serializable with Logging {
   }
 
   def clear(): Unit = {
-    val reserved = settings.asScala.filterKeys(staticConfKeys.contains).toMap
     settings.clear()
-    settings.putAll(reserved.asJava)
   }
 
   override def clone(): SQLConf = {
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index 17d4fcacac8e..c244e3bf7621 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -116,12 +116,12 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
   }
 
   test("reset - static and spark conf") {
-    val conf = spark.sessionState.conf.getAllConfs
+    val conf = spark.sparkContext.getConf.getAll.toMap
     val appName = conf.get("spark.app.name")
     val driverHost = conf.get("spark.driver.host")
     val master = conf.get("spark.master")
     val warehouseDir = conf.get("spark.sql.warehouse.dir")
-    // ensure the conf here is not default value, and will not be reset to default value
+    // ensure the conf here is not default value, and will not be reset to default value later
     assert(warehouseDir.get.contains(this.getClass.getCanonicalName))
     sql(s"reset")
     assert(conf.get("spark.app.name") === appName)
@@ -233,8 +233,8 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
   test("default value of WAREHOUSE_PATH") {
     // JVM adds a trailing slash if the directory exists and leaves it as-is, if it doesn't
     // In our comparison, strip trailing slash off of both sides, to account for such cases
-    assert(new Path(Utils.resolveURI(s"spark-warehouse/${classOf[SQLConfSuite].getCanonicalName}"))
-        .toString.stripSuffix("/") === spark.sessionState.conf.warehousePath.stripSuffix("/"))
+    assert(new Path(Utils.resolveURI("spark-warehouse")).toString.stripSuffix("/") ===
+      spark.sessionState.conf.warehousePath.stripSuffix("/"))
   }
 
   test("static SQL conf comes from SparkConf") {

From 460c35b940b040f414f01ff8156c46ff02646888 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 19:06:05 +0800
Subject: [PATCH 07/10] unnecessary

---
 .../org/apache/spark/sql/SQLQuerySuite.scala  | 19 ++++++++++++-------
 .../spark/sql/internal/SQLConfSuite.scala     |  6 +++---
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index 477f195df311..15f53a203d68 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -1021,29 +1021,34 @@ class SQLQuerySuite extends QueryTest with SharedSparkSession with AdaptiveSpark
   }
 
   test("SET commands semantics using sql()") {
+    spark.sessionState.conf.clear()
     val testKey = "test.key.0"
     val testVal = "test.val.0"
     val nonexistentKey = "nonexistent"
 
     // "set" itself returns all config variables currently specified in SQLConf.
-    TestSQLContext.overrideConfs.foreach { case (k, _) =>
-      assert(sql("SET").where(s"key ='$k'").collect().head.get(1) ===
-        TestSQLContext.overrideConfs(k))
+    assert(sql("SET").collect().size === TestSQLContext.overrideConfs.size)
+    sql("SET").collect().foreach { row =>
+      val key = row.getString(0)
+      val value = row.getString(1)
+      assert(TestSQLContext.overrideConfs.contains(key),
+        s"$key should exist in SQLConf.")
+      assert(TestSQLContext.overrideConfs(key) === value,
+        s"The value of $key should be ${TestSQLContext.overrideConfs(key)} instead of $value.")
     }
-
-    val originalConfs = sql("SET").collect()
+      val overrideConfs = sql("SET").collect()
 
     // "set key=val"
     sql(s"SET $testKey=$testVal")
     checkAnswer(
       sql("SET"),
-      originalConfs ++ Seq(Row(testKey, testVal))
+      overrideConfs ++ Seq(Row(testKey, testVal))
     )
 
     sql(s"SET ${testKey + testKey}=${testVal + testVal}")
     checkAnswer(
       sql("set"),
-      originalConfs ++ Seq(Row(testKey, testVal), Row(testKey + testKey, testVal + testVal))
+      overrideConfs ++ Seq(Row(testKey, testVal), Row(testKey + testKey, testVal + testVal))
     )
 
     // "set key"
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index c244e3bf7621..59f327075641 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -45,7 +45,7 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
     // Clear the conf.
     spark.sessionState.conf.clear()
     // After clear, only overrideConfs used by unit test should be in the SQLConf.
-    assert((spark.conf.getAll -- TestSQLContext.overrideConfs.keys).size < spark.conf.getAll.size)
+    assert(spark.conf.getAll === TestSQLContext.overrideConfs)
 
     spark.conf.set(testKey, testVal)
     assert(spark.conf.get(testKey) === testVal)
@@ -233,8 +233,8 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
   test("default value of WAREHOUSE_PATH") {
     // JVM adds a trailing slash if the directory exists and leaves it as-is, if it doesn't
     // In our comparison, strip trailing slash off of both sides, to account for such cases
-    assert(new Path(Utils.resolveURI("spark-warehouse")).toString.stripSuffix("/") ===
-      spark.sessionState.conf.warehousePath.stripSuffix("/"))
+    assert(new Path(Utils.resolveURI("spark-warehouse")).toString.stripSuffix("/") === spark
+      .sessionState.conf.warehousePath.stripSuffix("/"))
   }
 
   test("static SQL conf comes from SparkConf") {

From 8363a14994b3b11c8532e8896ca7b7d9b2d28ed0 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 19:07:30 +0800
Subject: [PATCH 08/10] unnecessary

---
 .../test/scala/org/apache/spark/sql/SQLQuerySuite.scala   | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
index 15f53a203d68..de0f7801a39a 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala
@@ -1031,12 +1031,14 @@ class SQLQuerySuite extends QueryTest with SharedSparkSession with AdaptiveSpark
     sql("SET").collect().foreach { row =>
       val key = row.getString(0)
       val value = row.getString(1)
-      assert(TestSQLContext.overrideConfs.contains(key),
+      assert(
+        TestSQLContext.overrideConfs.contains(key),
         s"$key should exist in SQLConf.")
-      assert(TestSQLContext.overrideConfs(key) === value,
+      assert(
+        TestSQLContext.overrideConfs(key) === value,
         s"The value of $key should be ${TestSQLContext.overrideConfs(key)} instead of $value.")
     }
-      val overrideConfs = sql("SET").collect()
+    val overrideConfs = sql("SET").collect()
 
     // "set key=val"
     sql(s"SET $testKey=$testVal")

From 45c926e478b05deca7232fd9305b5ed1bc622441 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 19:56:23 +0800
Subject: [PATCH 09/10] address comments

---
 docs/sql-ref-syntax-aux-conf-mgmt-reset.md                      | 2 +-
 .../test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
index 085f21b638bd..5ebc7b97ef64 100644
--- a/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
+++ b/docs/sql-ref-syntax-aux-conf-mgmt-reset.md
@@ -30,7 +30,7 @@ RESET
 
 ### Examples
 {% highlight sql %}
--- Reset all the properties specific to the current session to their default values.
+-- Reset any runtime configurations specific to the current session which were set via the SET command to their default values.
 RESET;
 {% endhighlight %}
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index 59f327075641..96f7788c886f 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -115,7 +115,7 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
     }
   }
 
-  test("reset - static and spark conf") {
+  test("reset will not change static sql configs and spark core configs") {
     val conf = spark.sparkContext.getConf.getAll.toMap
     val appName = conf.get("spark.app.name")
     val driverHost = conf.get("spark.driver.host")

From d374c57903057ac5914ab05597c5bf048ec97b75 Mon Sep 17 00:00:00 2001
From: Kent Yao <yaooqinn@hotmail.com>
Date: Wed, 25 Mar 2020 21:18:29 +0800
Subject: [PATCH 10/10] nit

---
 .../test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
index 96f7788c886f..e669794056ed 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/internal/SQLConfSuite.scala
@@ -123,7 +123,7 @@ class SQLConfSuite extends QueryTest with SharedSparkSession {
     val warehouseDir = conf.get("spark.sql.warehouse.dir")
     // ensure the conf here is not default value, and will not be reset to default value later
     assert(warehouseDir.get.contains(this.getClass.getCanonicalName))
-    sql(s"reset")
+    sql("RESET")
     assert(conf.get("spark.app.name") === appName)
     assert(conf.get("spark.driver.host") === driverHost)
     assert(conf.get("spark.master") === master)