From d44f56e1e1064f7ecf422fbcb59be780da8a3a8c Mon Sep 17 00:00:00 2001
From: Terry Kim <yuminkim@gmail.com>
Date: Sat, 16 Oct 2021 21:50:30 -0700
Subject: [PATCH 1/8] initial commit

---
 .../sql/catalyst/parser/DDLParserSuite.scala  |  9 ---
 .../sql/connector/DataSourceV2SQLSuite.scala  | 39 -----------
 .../sql/execution/command/DDLSuite.scala      | 58 +++++++---------
 .../DescribeNamespaceParserSuite.scala        | 33 +++++++++
 .../command/DescribeNamespaceSuiteBase.scala  | 51 ++++++++++++++
 .../command/v1/DescribeNamespaceSuite.scala   | 60 ++++++++++++++++
 .../command/v2/DescribeNamespaceSuite.scala   | 68 +++++++++++++++++++
 .../command/DescribeNamespaceSuite.scala      | 26 +++++++
 8 files changed, 262 insertions(+), 82 deletions(-)
 create mode 100644 sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
 create mode 100644 sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
 create mode 100644 sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala
 create mode 100644 sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala
 create mode 100644 sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/command/DescribeNamespaceSuite.scala

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/DDLParserSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/DDLParserSuite.scala
index 7bcc2b7f0c3d..44b2e20ee821 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/DDLParserSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/DDLParserSuite.scala
@@ -1193,15 +1193,6 @@ class DDLParserSuite extends AnalysisTest {
         "DESC TABLE COLUMN for a specific partition is not supported"))
   }
 
-  test("describe database") {
-    val sql1 = "DESCRIBE DATABASE EXTENDED a.b"
-    val sql2 = "DESCRIBE DATABASE a.b"
-    comparePlans(parsePlan(sql1),
-      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
-    comparePlans(parsePlan(sql2),
-      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = false))
-  }
-
   test("SPARK-17328 Fix NPE with EXPLAIN DESCRIBE TABLE") {
     comparePlans(parsePlan("describe t"),
       DescribeRelation(
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/connector/DataSourceV2SQLSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/connector/DataSourceV2SQLSuite.scala
index 360c8beff436..7c4a5ea22b16 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/connector/DataSourceV2SQLSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/connector/DataSourceV2SQLSuite.scala
@@ -1233,26 +1233,6 @@ class DataSourceV2SQLSuite
     assert(exception.getMessage.contains("Namespace 'ns1' not found"))
   }
 
-  test("DescribeNamespace using v2 catalog") {
-    withNamespace("testcat.ns1.ns2") {
-      sql("CREATE NAMESPACE IF NOT EXISTS testcat.ns1.ns2 COMMENT " +
-        "'test namespace' LOCATION '/tmp/ns_test'")
-      val descriptionDf = sql("DESCRIBE NAMESPACE testcat.ns1.ns2")
-      assert(descriptionDf.schema.map(field => (field.name, field.dataType)) ===
-        Seq(
-          ("info_name", StringType),
-          ("info_value", StringType)
-        ))
-      val description = descriptionDf.collect()
-      assert(description === Seq(
-        Row("Namespace Name", "ns2"),
-        Row(SupportsNamespaces.PROP_COMMENT.capitalize, "test namespace"),
-        Row(SupportsNamespaces.PROP_LOCATION.capitalize, "/tmp/ns_test"),
-        Row(SupportsNamespaces.PROP_OWNER.capitalize, defaultUser))
-      )
-    }
-  }
-
   test("ALTER NAMESPACE .. SET PROPERTIES using v2 catalog") {
     withNamespace("testcat.ns1.ns2") {
       sql("CREATE NAMESPACE IF NOT EXISTS testcat.ns1.ns2 COMMENT " +
@@ -2810,25 +2790,6 @@ class DataSourceV2SQLSuite
     }
   }
 
-  test("SPARK-34577: drop/add columns to a dataset of `DESCRIBE NAMESPACE`") {
-    withNamespace("ns") {
-      sql("CREATE NAMESPACE ns")
-      val description = sql(s"DESCRIBE NAMESPACE ns")
-      val noCommentDataset = description.drop("info_name")
-      val expectedSchema = new StructType()
-        .add(
-          name = "info_value",
-          dataType = StringType,
-          nullable = true,
-          metadata = new MetadataBuilder()
-            .putString("comment", "value of the namespace info").build())
-      assert(noCommentDataset.schema === expectedSchema)
-      val isNullDataset = noCommentDataset
-        .withColumn("is_null", noCommentDataset("info_value").isNull)
-      assert(isNullDataset.schema === expectedSchema.add("is_null", BooleanType, false))
-    }
-  }
-
   test("SPARK-34923: do not propagate metadata columns through Project") {
     val t1 = s"${catalogAndNamespace}table"
     withTable(t1) {
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
index ba87883b64e0..798b0f2c8ada 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
@@ -225,7 +225,29 @@ class InMemoryCatalogedDDLSuite extends DDLSuite with SharedSparkSession {
   }
 }
 
-abstract class DDLSuite extends QueryTest with SQLTestUtils {
+trait CommandTestUtils extends SQLTestUtils {
+  private val escapedIdentifier = "`(.+)`".r
+
+  /**
+   * Strip backticks, if any, from the string.
+   */
+  protected def cleanIdentifier(ident: String): String = {
+    ident match {
+      case escapedIdentifier(i) => i
+      case plainIdent => plainIdent
+    }
+  }
+
+  /**
+   * Returns the path to the database of the given name.
+   */
+  protected def getDBPath(dbName: String): URI = {
+    val warehousePath = makeQualifiedPath(spark.sessionState.conf.warehousePath)
+    new Path(CatalogUtils.URIToString(warehousePath), s"$dbName.db").toUri
+  }
+}
+
+abstract class DDLSuite extends QueryTest with CommandTestUtils {
 
   protected val reversedProperties = Seq(PROP_OWNER)
 
@@ -239,8 +261,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
       isDataSource: Boolean = true,
       partitionCols: Seq[String] = Seq("a", "b")): CatalogTable
 
-  private val escapedIdentifier = "`(.+)`".r
-
   private def dataSource: String = {
     if (isUsingHiveMetastore) {
       "HIVE"
@@ -258,16 +278,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
     assert(normalizeCatalogTable(actual) == normalizeCatalogTable(expected))
   }
 
-  /**
-   * Strip backticks, if any, from the string.
-   */
-  private def cleanIdentifier(ident: String): String = {
-    ident match {
-      case escapedIdentifier(i) => i
-      case plainIdent => plainIdent
-    }
-  }
-
   private def assertUnsupported(query: String): Unit = {
     val e = intercept[AnalysisException] {
       sql(query)
@@ -304,11 +314,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
     catalog.createPartitions(tableName, Seq(part), ignoreIfExists = false)
   }
 
-  private def getDBPath(dbName: String): URI = {
-    val warehousePath = makeQualifiedPath(spark.sessionState.conf.warehousePath)
-    new Path(CatalogUtils.URIToString(warehousePath), s"$dbName.db").toUri
-  }
-
   test("alter table: set location (datasource table)") {
     testSetLocation(isDatasourceTable = true)
   }
@@ -757,14 +762,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
 
         sql(s"CREATE DATABASE $dbName")
 
-        checkAnswer(
-          sql(s"DESCRIBE DATABASE EXTENDED $dbName").toDF("key", "value")
-            .where("key not like 'Owner%'"), // filter for consistency with in-memory catalog
-          Row("Database Name", dbNameWithoutBackTicks) ::
-            Row("Comment", "") ::
-            Row("Location", CatalogUtils.URIToString(location)) ::
-            Row("Properties", "") :: Nil)
-
         sql(s"ALTER DATABASE $dbName SET DBPROPERTIES ('a'='a', 'b'='b', 'c'='c')")
 
         checkAnswer(
@@ -813,7 +810,7 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
     }
   }
 
-  test("Drop/Alter/Describe Database - database does not exists") {
+  test("Drop/Alter Database - database does not exists") {
     val databaseNames = Seq("db1", "`database`")
 
     databaseNames.foreach { dbName =>
@@ -829,13 +826,6 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
         sql(s"ALTER DATABASE $dbName SET DBPROPERTIES ('d'='d')")
       }.getMessage
       assert(message.contains(s"Database '$dbNameWithoutBackTicks' not found"))
-
-      message = intercept[AnalysisException] {
-        sql(s"DESCRIBE DATABASE EXTENDED $dbName")
-      }.getMessage
-      assert(message.contains(s"Database '$dbNameWithoutBackTicks' not found"))
-
-      sql(s"DROP DATABASE IF EXISTS $dbName")
     }
   }
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
new file mode 100644
index 000000000000..5b0ed9f90e9f
--- /dev/null
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command
+
+import org.apache.spark.sql.catalyst.analysis.{AnalysisTest, UnresolvedNamespace}
+import org.apache.spark.sql.catalyst.parser.CatalystSqlParser.parsePlan
+import org.apache.spark.sql.catalyst.plans.logical.DescribeNamespace
+
+class DescribeNamespaceParserSuite extends AnalysisTest {
+  test("describe namespace") {
+    val sql1 = "DESCRIBE NAMESPACE EXTENDED a.b"
+    val sql2 = "DESCRIBE NAMESPACE a.b"
+    comparePlans(parsePlan(sql1),
+      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
+    comparePlans(parsePlan(sql2),
+      DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = false))
+  }
+}
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
new file mode 100644
index 000000000000..4ff6d2fc8737
--- /dev/null
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command
+
+import org.apache.spark.sql.{AnalysisException, QueryTest}
+
+/**
+ * This base suite contains unified tests for the `DESCRIBE NAMESPACE` command that check V1 and V2
+ * table catalogs. The tests that cannot run for all supported catalogs are located in more
+ * specific test suites:
+ *
+ *   - V2 table catalog tests: `org.apache.spark.sql.execution.command.v2.DescribeNamespaceSuite`
+ *   - V1 table catalog tests:
+ *     `org.apache.spark.sql.execution.command.v1.DescribeNamespaceSuiteBase`
+ *     - V1 In-Memory catalog: `org.apache.spark.sql.execution.command.v1.DescribeNamespaceSuite`
+ *     - V1 Hive External catalog:
+*        `org.apache.spark.sql.hive.execution.command.DescribeNamespaceSuite`
+ */
+trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils with CommandTestUtils {
+  override val command = "DESCRIBE NAMESPACE"
+
+  test("namespace does not exists") {
+    val databaseNames = Seq("db1", "`database`")
+    databaseNames.foreach { dbName =>
+      val dbNameWithoutBackTicks = cleanIdentifier(dbName)
+      val message = intercept[AnalysisException] {
+        sql(s"DESCRIBE NAMESPACE EXTENDED $catalog.$dbName")
+      }.getMessage
+
+      val prefix = if (catalogVersion == "V2") "Namespace" else "Database"
+      assert(message.contains(s"$prefix '$dbNameWithoutBackTicks' not found"))
+
+      sql(s"DROP NAMESPACE IF EXISTS $catalog.$dbName")
+    }
+  }
+}
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala
new file mode 100644
index 000000000000..e29999a552f7
--- /dev/null
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala
@@ -0,0 +1,60 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command.v1
+
+import org.apache.spark.sql.Row
+import org.apache.spark.sql.catalyst.catalog.CatalogUtils
+import org.apache.spark.sql.execution.command
+
+/**
+ * This base suite contains unified tests for the `DESCRIBE NAMESPACE` command that checks V1
+ * table catalogs. The tests that cannot run for all V1 catalogs are located in more
+ * specific test suites:
+ *
+ *   - V1 In-Memory catalog: `org.apache.spark.sql.execution.command.v1.DescribeNamespaceSuite`
+ *   - V1 Hive External catalog:
+ *     `org.apache.spark.sql.hive.execution.command.DescribeNamespaceSuite`
+ */
+trait DescribeNamespaceSuiteBase extends command.DescribeNamespaceSuiteBase {
+  test("basic") {
+    val namespaceNames = Seq("db1", "`database`")
+    withNamespace(namespaceNames: _*) {
+      namespaceNames.foreach { ns =>
+        val dbNameWithoutBackTicks = cleanIdentifier(ns)
+        val location = getDBPath(dbNameWithoutBackTicks)
+
+        sql(s"CREATE NAMESPACE $ns")
+
+        checkAnswer(
+          sql(s"DESCRIBE NAMESPACE EXTENDED $ns")
+            .toDF("key", "value")
+            .where("key not like 'Owner%'"), // filter for consistency with in-memory catalog
+          Row("Database Name", dbNameWithoutBackTicks) ::
+            Row("Comment", "") ::
+            Row("Location", CatalogUtils.URIToString(location)) ::
+            Row("Properties", "") :: Nil)
+      }
+    }
+  }
+}
+
+/**
+ * The class contains tests for the `DESCRIBE NAMESPACE` command to check V1 In-Memory
+ * table catalog.
+ */
+class DescribeNamespaceSuite extends DescribeNamespaceSuiteBase with CommandSuiteBase
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala
new file mode 100644
index 000000000000..5a096401d50a
--- /dev/null
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala
@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.execution.command.v2
+
+import org.apache.spark.sql.Row
+import org.apache.spark.sql.connector.catalog.SupportsNamespaces
+import org.apache.spark.sql.execution.command
+import org.apache.spark.sql.types.{BooleanType, MetadataBuilder, StringType, StructType}
+import org.apache.spark.util.Utils
+
+/**
+ * The class contains tests for the `DESCRIBE NAMESPACE` command to check V2 table catalogs.
+ */
+class DescribeNamespaceSuite extends command.DescribeNamespaceSuiteBase with CommandSuiteBase {
+  test("DescribeNamespace using v2 catalog") {
+    withNamespace("test_catalog.ns1.ns2") {
+      sql("CREATE NAMESPACE IF NOT EXISTS test_catalog.ns1.ns2 COMMENT " +
+        "'test namespace' LOCATION '/tmp/ns_test'")
+      val descriptionDf = sql("DESCRIBE NAMESPACE test_catalog.ns1.ns2")
+      assert(descriptionDf.schema.map(field => (field.name, field.dataType)) ===
+        Seq(
+          ("info_name", StringType),
+          ("info_value", StringType)
+        ))
+      val description = descriptionDf.collect()
+      assert(description === Seq(
+        Row("Namespace Name", "ns2"),
+        Row(SupportsNamespaces.PROP_COMMENT.capitalize, "test namespace"),
+        Row(SupportsNamespaces.PROP_LOCATION.capitalize, "/tmp/ns_test"),
+        Row(SupportsNamespaces.PROP_OWNER.capitalize, Utils.getCurrentUserName()))
+      )
+    }
+  }
+
+  test("SPARK-34577: drop/add columns to a dataset of `DESCRIBE NAMESPACE`") {
+    withNamespace("ns") {
+      sql("CREATE NAMESPACE ns")
+      val description = sql(s"DESCRIBE NAMESPACE ns")
+      val noCommentDataset = description.drop("info_name")
+      val expectedSchema = new StructType()
+        .add(
+          name = "info_value",
+          dataType = StringType,
+          nullable = true,
+          metadata = new MetadataBuilder()
+            .putString("comment", "value of the namespace info").build())
+      assert(noCommentDataset.schema === expectedSchema)
+      val isNullDataset = noCommentDataset
+        .withColumn("is_null", noCommentDataset("info_value").isNull)
+      assert(isNullDataset.schema === expectedSchema.add("is_null", BooleanType, false))
+    }
+  }
+}
diff --git a/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/command/DescribeNamespaceSuite.scala b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/command/DescribeNamespaceSuite.scala
new file mode 100644
index 000000000000..866cc178012d
--- /dev/null
+++ b/sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/command/DescribeNamespaceSuite.scala
@@ -0,0 +1,26 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.hive.execution.command
+
+import org.apache.spark.sql.execution.command.v1
+
+/**
+ * The class contains tests for the `DESCRIBE NAMESPACE` command to check V1 Hive external
+ * table catalog.
+ */
+class DescribeNamespaceSuite extends v1.DescribeNamespaceSuiteBase with CommandSuiteBase

From 69ab022108a1586b44227d0d3ea30101529579c1 Mon Sep 17 00:00:00 2001
From: Terry Kim <yuminkim@gmail.com>
Date: Sun, 24 Oct 2021 11:44:23 -0700
Subject: [PATCH 2/8] address PR comments

---
 .../sql/execution/command/DDLSuite.scala      | 44 +++++++++----------
 .../DescribeNamespaceParserSuite.scala        |  3 ++
 .../command/DescribeNamespaceSuiteBase.scala  | 20 ++++-----
 .../command/v1/DescribeNamespaceSuite.scala   | 31 +++++++------
 .../command/v2/DescribeNamespaceSuite.scala   |  8 ++--
 5 files changed, 53 insertions(+), 53 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
index 798b0f2c8ada..1b09a5dd6a45 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
@@ -225,29 +225,7 @@ class InMemoryCatalogedDDLSuite extends DDLSuite with SharedSparkSession {
   }
 }
 
-trait CommandTestUtils extends SQLTestUtils {
-  private val escapedIdentifier = "`(.+)`".r
-
-  /**
-   * Strip backticks, if any, from the string.
-   */
-  protected def cleanIdentifier(ident: String): String = {
-    ident match {
-      case escapedIdentifier(i) => i
-      case plainIdent => plainIdent
-    }
-  }
-
-  /**
-   * Returns the path to the database of the given name.
-   */
-  protected def getDBPath(dbName: String): URI = {
-    val warehousePath = makeQualifiedPath(spark.sessionState.conf.warehousePath)
-    new Path(CatalogUtils.URIToString(warehousePath), s"$dbName.db").toUri
-  }
-}
-
-abstract class DDLSuite extends QueryTest with CommandTestUtils {
+abstract class DDLSuite extends QueryTest with SQLTestUtils {
 
   protected val reversedProperties = Seq(PROP_OWNER)
 
@@ -261,6 +239,8 @@ abstract class DDLSuite extends QueryTest with CommandTestUtils {
       isDataSource: Boolean = true,
       partitionCols: Seq[String] = Seq("a", "b")): CatalogTable
 
+  private val escapedIdentifier = "`(.+)`".r
+
   private def dataSource: String = {
     if (isUsingHiveMetastore) {
       "HIVE"
@@ -278,6 +258,16 @@ abstract class DDLSuite extends QueryTest with CommandTestUtils {
     assert(normalizeCatalogTable(actual) == normalizeCatalogTable(expected))
   }
 
+  /**
+   * Strip backticks, if any, from the string.
+   */
+  protected def cleanIdentifier(ident: String): String = {
+    ident match {
+      case escapedIdentifier(i) => i
+      case plainIdent => plainIdent
+    }
+  }
+
   private def assertUnsupported(query: String): Unit = {
     val e = intercept[AnalysisException] {
       sql(query)
@@ -314,6 +304,14 @@ abstract class DDLSuite extends QueryTest with CommandTestUtils {
     catalog.createPartitions(tableName, Seq(part), ignoreIfExists = false)
   }
 
+  /**
+   * Returns the path to the database of the given name.
+   */
+  protected def getDBPath(dbName: String): URI = {
+    val warehousePath = makeQualifiedPath(spark.sessionState.conf.warehousePath)
+    new Path(CatalogUtils.URIToString(warehousePath), s"$dbName.db").toUri
+  }
+
   test("alter table: set location (datasource table)") {
     testSetLocation(isDatasourceTable = true)
   }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
index 5b0ed9f90e9f..f6254da23a21 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
@@ -25,9 +25,12 @@ class DescribeNamespaceParserSuite extends AnalysisTest {
   test("describe namespace") {
     val sql1 = "DESCRIBE NAMESPACE EXTENDED a.b"
     val sql2 = "DESCRIBE NAMESPACE a.b"
+    val sql3 = "DESCRIBE NAMESPACE cat.`database`"
     comparePlans(parsePlan(sql1),
       DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
     comparePlans(parsePlan(sql2),
       DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = false))
+    comparePlans(parsePlan(sql3),
+      DescribeNamespace(UnresolvedNamespace(Seq("cat", "database")), extended = false))
   }
 }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
index 4ff6d2fc8737..3e58be07f5d0 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
@@ -31,21 +31,19 @@ import org.apache.spark.sql.{AnalysisException, QueryTest}
  *     - V1 Hive External catalog:
 *        `org.apache.spark.sql.hive.execution.command.DescribeNamespaceSuite`
  */
-trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils with CommandTestUtils {
+trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils {
   override val command = "DESCRIBE NAMESPACE"
 
+  protected def notFoundMsgPrefix: String
+
   test("namespace does not exists") {
-    val databaseNames = Seq("db1", "`database`")
-    databaseNames.foreach { dbName =>
-      val dbNameWithoutBackTicks = cleanIdentifier(dbName)
-      val message = intercept[AnalysisException] {
-        sql(s"DESCRIBE NAMESPACE EXTENDED $catalog.$dbName")
-      }.getMessage
+    val dbName = "db1"
+    val message = intercept[AnalysisException] {
+      sql(s"DESCRIBE NAMESPACE EXTENDED $catalog.$dbName")
+    }.getMessage
 
-      val prefix = if (catalogVersion == "V2") "Namespace" else "Database"
-      assert(message.contains(s"$prefix '$dbNameWithoutBackTicks' not found"))
+    assert(message.contains(s"$notFoundMsgPrefix '$dbName' not found"))
 
-      sql(s"DROP NAMESPACE IF EXISTS $catalog.$dbName")
-    }
+    sql(s"DROP NAMESPACE IF EXISTS $catalog.$dbName")
   }
 }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala
index e29999a552f7..a86e4a51b052 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v1/DescribeNamespaceSuite.scala
@@ -18,7 +18,6 @@
 package org.apache.spark.sql.execution.command.v1
 
 import org.apache.spark.sql.Row
-import org.apache.spark.sql.catalyst.catalog.CatalogUtils
 import org.apache.spark.sql.execution.command
 
 /**
@@ -31,24 +30,24 @@ import org.apache.spark.sql.execution.command
  *     `org.apache.spark.sql.hive.execution.command.DescribeNamespaceSuite`
  */
 trait DescribeNamespaceSuiteBase extends command.DescribeNamespaceSuiteBase {
+  override def notFoundMsgPrefix: String = "Database"
+
   test("basic") {
-    val namespaceNames = Seq("db1", "`database`")
-    withNamespace(namespaceNames: _*) {
-      namespaceNames.foreach { ns =>
-        val dbNameWithoutBackTicks = cleanIdentifier(ns)
-        val location = getDBPath(dbNameWithoutBackTicks)
+    val ns = "db1"
+    withNamespace(ns) {
+      sql(s"CREATE NAMESPACE $ns")
 
-        sql(s"CREATE NAMESPACE $ns")
+      val result = sql(s"DESCRIBE NAMESPACE EXTENDED $ns")
+        .toDF("key", "value")
+        .where("key not like 'Owner%'") // filter for consistency with in-memory catalog
+        .collect()
 
-        checkAnswer(
-          sql(s"DESCRIBE NAMESPACE EXTENDED $ns")
-            .toDF("key", "value")
-            .where("key not like 'Owner%'"), // filter for consistency with in-memory catalog
-          Row("Database Name", dbNameWithoutBackTicks) ::
-            Row("Comment", "") ::
-            Row("Location", CatalogUtils.URIToString(location)) ::
-            Row("Properties", "") :: Nil)
-      }
+      assert(result.length == 4)
+      assert(result(0) === Row("Database Name", ns))
+      assert(result(1) === Row("Comment", ""))
+      // Check only the key for "Location" since its value depends on warehouse path, etc.
+      assert(result(2).getString(0) === "Location")
+      assert(result(3) === Row("Properties", ""))
     }
   }
 }
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala
index 5a096401d50a..a98c6a486ae5 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/v2/DescribeNamespaceSuite.scala
@@ -27,11 +27,13 @@ import org.apache.spark.util.Utils
  * The class contains tests for the `DESCRIBE NAMESPACE` command to check V2 table catalogs.
  */
 class DescribeNamespaceSuite extends command.DescribeNamespaceSuiteBase with CommandSuiteBase {
+  override def notFoundMsgPrefix: String = "Namespace"
+
   test("DescribeNamespace using v2 catalog") {
-    withNamespace("test_catalog.ns1.ns2") {
-      sql("CREATE NAMESPACE IF NOT EXISTS test_catalog.ns1.ns2 COMMENT " +
+    withNamespace(s"$catalog.ns1.ns2") {
+      sql(s"CREATE NAMESPACE IF NOT EXISTS $catalog.ns1.ns2 COMMENT " +
         "'test namespace' LOCATION '/tmp/ns_test'")
-      val descriptionDf = sql("DESCRIBE NAMESPACE test_catalog.ns1.ns2")
+      val descriptionDf = sql(s"DESCRIBE NAMESPACE $catalog.ns1.ns2")
       assert(descriptionDf.schema.map(field => (field.name, field.dataType)) ===
         Seq(
           ("info_name", StringType),

From 002b4e718ac5d7407ce3e1405057eb56a1006a27 Mon Sep 17 00:00:00 2001
From: Terry Kim <yuminkim@gmail.com>
Date: Sun, 24 Oct 2021 11:45:49 -0700
Subject: [PATCH 3/8] minor fix

---
 .../org/apache/spark/sql/execution/command/DDLSuite.scala  | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
index 1b09a5dd6a45..a3868666f979 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DDLSuite.scala
@@ -261,7 +261,7 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
   /**
    * Strip backticks, if any, from the string.
    */
-  protected def cleanIdentifier(ident: String): String = {
+  private def cleanIdentifier(ident: String): String = {
     ident match {
       case escapedIdentifier(i) => i
       case plainIdent => plainIdent
@@ -304,10 +304,7 @@ abstract class DDLSuite extends QueryTest with SQLTestUtils {
     catalog.createPartitions(tableName, Seq(part), ignoreIfExists = false)
   }
 
-  /**
-   * Returns the path to the database of the given name.
-   */
-  protected def getDBPath(dbName: String): URI = {
+  private def getDBPath(dbName: String): URI = {
     val warehousePath = makeQualifiedPath(spark.sessionState.conf.warehousePath)
     new Path(CatalogUtils.URIToString(warehousePath), s"$dbName.db").toUri
   }

From 2640444646e41788788fd28ba604fe706eedb974 Mon Sep 17 00:00:00 2001
From: Terry Kim <yuminkim@gmail.com>
Date: Sun, 24 Oct 2021 11:47:16 -0700
Subject: [PATCH 4/8] update variable name

---
 .../execution/command/DescribeNamespaceSuiteBase.scala    | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
index 3e58be07f5d0..fe484fc76be2 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
@@ -37,13 +37,13 @@ trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils {
   protected def notFoundMsgPrefix: String
 
   test("namespace does not exists") {
-    val dbName = "db1"
+    val ns = "db1"
     val message = intercept[AnalysisException] {
-      sql(s"DESCRIBE NAMESPACE EXTENDED $catalog.$dbName")
+      sql(s"DESCRIBE NAMESPACE EXTENDED $catalog.$ns")
     }.getMessage
 
-    assert(message.contains(s"$notFoundMsgPrefix '$dbName' not found"))
+    assert(message.contains(s"$notFoundMsgPrefix '$ns' not found"))
 
-    sql(s"DROP NAMESPACE IF EXISTS $catalog.$dbName")
+    sql(s"DROP NAMESPACE IF EXISTS $catalog.$ns")
   }
 }

From 174aeddcc2ced1e014b9ab2ce8d7d4ded7e42bf4 Mon Sep 17 00:00:00 2001
From: Wenchen Fan <cloud0fan@gmail.com>
Date: Mon, 25 Oct 2021 17:00:16 +0800
Subject: [PATCH 5/8] Update DescribeNamespaceParserSuite.scala

---
 .../command/DescribeNamespaceParserSuite.scala  | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
index f6254da23a21..7d054e76f46d 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
@@ -23,14 +23,17 @@ import org.apache.spark.sql.catalyst.plans.logical.DescribeNamespace
 
 class DescribeNamespaceParserSuite extends AnalysisTest {
   test("describe namespace") {
-    val sql1 = "DESCRIBE NAMESPACE EXTENDED a.b"
-    val sql2 = "DESCRIBE NAMESPACE a.b"
-    val sql3 = "DESCRIBE NAMESPACE cat.`database`"
-    comparePlans(parsePlan(sql1),
+    def check(sql: String, expected: LogicalPlan): Unit = {
+      comparePlans(parsePlan(sql), expected)
+      comparePlans(parsePlan(sql.replace("NAMESPACE", "DATABASE")), expected)
+      comparePlans(parsePlan(sql.replace("NAMESPACE", "SCHEMA")), expected)
+    }
+    
+    check("DESCRIBE NAMESPACE EXTENDED a.b",
       DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
-    comparePlans(parsePlan(sql2),
+    check("DESCRIBE NAMESPACE a.b",
       DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = false))
-    comparePlans(parsePlan(sql3),
-      DescribeNamespace(UnresolvedNamespace(Seq("cat", "database")), extended = false))
+    check("DESCRIBE NAMESPACE `a.b`",
+      DescribeNamespace(UnresolvedNamespace(Seq("a.b")), extended = false))
   }
 }

From cecd0a65b6472de6baea362f30887d4f19028845 Mon Sep 17 00:00:00 2001
From: Wenchen Fan <cloud0fan@gmail.com>
Date: Mon, 25 Oct 2021 17:00:27 +0800
Subject: [PATCH 6/8] Update
 sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala

---
 .../sql/execution/command/DescribeNamespaceSuiteBase.scala      | 2 --
 1 file changed, 2 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
index fe484fc76be2..d8462a2c9618 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
@@ -43,7 +43,5 @@ trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils {
     }.getMessage
 
     assert(message.contains(s"$notFoundMsgPrefix '$ns' not found"))
-
-    sql(s"DROP NAMESPACE IF EXISTS $catalog.$ns")
   }
 }

From a5c1492bfcaf55613039b4343f9e3f8c4303cc47 Mon Sep 17 00:00:00 2001
From: Terry Kim <yuminkim@gmail.com>
Date: Mon, 25 Oct 2021 09:22:30 -0700
Subject: [PATCH 7/8] fix compilation error

---
 .../sql/execution/command/DescribeNamespaceParserSuite.scala  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
index 7d054e76f46d..93da7aa0248f 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceParserSuite.scala
@@ -19,7 +19,7 @@ package org.apache.spark.sql.execution.command
 
 import org.apache.spark.sql.catalyst.analysis.{AnalysisTest, UnresolvedNamespace}
 import org.apache.spark.sql.catalyst.parser.CatalystSqlParser.parsePlan
-import org.apache.spark.sql.catalyst.plans.logical.DescribeNamespace
+import org.apache.spark.sql.catalyst.plans.logical.{DescribeNamespace, LogicalPlan}
 
 class DescribeNamespaceParserSuite extends AnalysisTest {
   test("describe namespace") {
@@ -28,7 +28,7 @@ class DescribeNamespaceParserSuite extends AnalysisTest {
       comparePlans(parsePlan(sql.replace("NAMESPACE", "DATABASE")), expected)
       comparePlans(parsePlan(sql.replace("NAMESPACE", "SCHEMA")), expected)
     }
-    
+
     check("DESCRIBE NAMESPACE EXTENDED a.b",
       DescribeNamespace(UnresolvedNamespace(Seq("a", "b")), extended = true))
     check("DESCRIBE NAMESPACE a.b",

From a8820abd45be0c10a7296acc00a66aa54020df60 Mon Sep 17 00:00:00 2001
From: Terry Kim <yuminkim@gmail.com>
Date: Mon, 25 Oct 2021 09:35:36 -0700
Subject: [PATCH 8/8] add back with TODO

---
 .../sql/execution/command/DescribeNamespaceSuiteBase.scala     | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
index d8462a2c9618..727bb90bb0cf 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/command/DescribeNamespaceSuiteBase.scala
@@ -43,5 +43,8 @@ trait DescribeNamespaceSuiteBase extends QueryTest with DDLCommandTestUtils {
     }.getMessage
 
     assert(message.contains(s"$notFoundMsgPrefix '$ns' not found"))
+
+    // TODO: Move this to DropNamespaceSuite when the test suite is introduced.
+    sql(s"DROP NAMESPACE IF EXISTS $catalog.$ns")
   }
 }