diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
index 6f302d3d0250..a5cf7196b21e 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/SessionCatalog.scala
@@ -20,7 +20,6 @@ package org.apache.spark.sql.catalyst.catalog
 import javax.annotation.concurrent.GuardedBy
 
 import scala.collection.mutable
-import scala.util.{Failure, Success, Try}
 
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.Path
@@ -1099,25 +1098,15 @@ class SessionCatalog(
   def listFunctions(db: String, pattern: String): Seq[(FunctionIdentifier, String)] = {
     val dbName = formatDatabaseName(db)
     requireDbExists(dbName)
-    val dbFunctions = externalCatalog.listFunctions(dbName, pattern).map { f =>
-      FunctionIdentifier(f, Some(dbName)) }
-    val loadedFunctions =
-      StringUtils.filterPattern(functionRegistry.listFunction(), pattern).map { f =>
-        // In functionRegistry, function names are stored as an unquoted format.
-        Try(parser.parseFunctionIdentifier(f)) match {
-          case Success(e) => e
-          case Failure(_) =>
-            // The names of some built-in functions are not parsable by our parser, e.g., %
-            FunctionIdentifier(f)
-        }
-      }
+    val dbFunctions = externalCatalog.listFunctions(dbName, pattern)
+      .map { f => FunctionIdentifier(f, Some(dbName)) }
+    val loadedFunctions = StringUtils.filterPattern(functionRegistry.listFunction(), pattern)
+      .map { f => FunctionIdentifier(f) }
     val functions = dbFunctions ++ loadedFunctions
-    // The session catalog caches some persistent functions in the FunctionRegistry
-    // so there can be duplicates.
     functions.map {
       case f if FunctionRegistry.functionSet.contains(f.funcName) => (f, "SYSTEM")
       case f => (f, "USER")
-    }.distinct
+    }
   }
 
 
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala
index 75272d295b16..ea5398761c46 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/command/functions.scala
@@ -208,6 +208,8 @@ case class ShowFunctionsCommand(
           case (f, "USER") if showUserFunctions => f.unquotedString
           case (f, "SYSTEM") if showSystemFunctions => f.unquotedString
         }
-    functionNames.sorted.map(Row(_))
+    // The session catalog caches some persistent functions in the FunctionRegistry
+    // so there can be duplicates.
+    functionNames.distinct.sorted.map(Row(_))
   }
 }
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 9368d0ba8ef6..78c80dacb9fa 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
@@ -539,23 +539,6 @@ class HiveUDFSuite extends QueryTest with TestHiveSingleton with SQLTestUtils {
       checkAnswer(testData.selectExpr("statelessUDF() as s").agg(max($"s")), Row(1))
     }
   }
-
-  test("Show persistent functions") {
-    val testData = spark.sparkContext.parallelize(StringCaseClass("") :: Nil).toDF()
-    withTempView("inputTable") {
-      testData.createOrReplaceTempView("inputTable")
-      withUserDefinedFunction("testUDFToListInt" -> false) {
-        val numFunc = spark.catalog.listFunctions().count()
-        sql(s"CREATE FUNCTION testUDFToListInt AS '${classOf[UDFToListInt].getName}'")
-        assert(spark.catalog.listFunctions().count() == numFunc + 1)
-        checkAnswer(
-          sql("SELECT testUDFToListInt(s) FROM inputTable"),
-          Seq(Row(Seq(1, 2, 3))))
-        assert(sql("show functions").count() == numFunc + 1)
-        assert(spark.catalog.listFunctions().count() == numFunc + 1)
-      }
-    }
-  }
 }
 
 class TestPair(x: Int, y: Int) extends Writable with Serializable {