diff --git a/spark-sql-application/src/main/java/org/opensearch/sql/FlintDelegatingSessionCatalog.java b/spark-sql-application/src/main/java/org/opensearch/sql/FlintDelegatingSessionCatalog.java
index 86c4caba8..6ed9fa980 100644
--- a/spark-sql-application/src/main/java/org/opensearch/sql/FlintDelegatingSessionCatalog.java
+++ b/spark-sql-application/src/main/java/org/opensearch/sql/FlintDelegatingSessionCatalog.java
@@ -39,6 +39,9 @@ public final void setDelegateCatalog(CatalogPlugin delegate) {
     // do nothing
   }
 
+  /**
+   * Using V2SessionCatalog name: spark_catalog.
+   */
   @Override
   public String name() {
     return delegate.name();
@@ -46,10 +49,8 @@ public String name() {
 
   @Override
   public final void initialize(String name, CaseInsensitiveStringMap options) {
-    delegate = SparkSession.getActiveSession()
-        .get()
-        .sessionState()
-        .catalogManager().v2SessionCatalog();
+    this.delegate =
+        SparkSession.getActiveSession().get().sessionState().catalogManager().v2SessionCatalog();
   }
 
   @Override
diff --git a/spark-sql-application/src/test/scala/org/opensearch/sql/FlintDelegatingSessionCatalogTest.scala b/spark-sql-application/src/test/scala/org/opensearch/sql/FlintDelegatingSessionCatalogTest.scala
index 7bd8d0397..f6be0b1c3 100644
--- a/spark-sql-application/src/test/scala/org/opensearch/sql/FlintDelegatingSessionCatalogTest.scala
+++ b/spark-sql-application/src/test/scala/org/opensearch/sql/FlintDelegatingSessionCatalogTest.scala
@@ -10,6 +10,7 @@ import org.apache.spark.sql.test.SharedSparkSessionBase
 
 class FlintDelegatingSessionCatalogTest extends QueryTest with SharedSparkSessionBase {
   private val testTable = "mycatalog.default.flint_sql_test"
+  private val testTableWithoutCatalog = "default.flint_sql_test"
 
   override def beforeAll(): Unit = {
     super.beforeAll()
@@ -18,30 +19,34 @@ class FlintDelegatingSessionCatalogTest extends QueryTest with SharedSparkSessio
       "spark.sql.catalog.mycatalog",
       "org.opensearch.sql.FlintDelegatingSessionCatalog")
 
-    // Create test table
-    spark.sql(s"""
-           | CREATE TABLE $testTable
-           | (
-           |   name STRING,
-           |   age INT
-           | )
-           | USING CSV
-           | OPTIONS (
-           |  header 'false',
-           |  delimiter '\t'
-           | )
-           |""".stripMargin)
-
-    spark.sql(s"""
-           | INSERT INTO $testTable
-           | VALUES ('Hello', 30)
-           | """.stripMargin)
+    sql(s"""
+                 | CREATE TABLE $testTable
+                 | (
+                 |   name STRING,
+                 |   age INT
+                 | )
+                 | USING CSV
+                 | OPTIONS (
+                 |  header 'false',
+                 |  delimiter '\t'
+                 | )
+                 |""".stripMargin)
+
+    sql(s"""
+                 | INSERT INTO $testTable
+                 | VALUES ('Hello', 30)
+                 | """.stripMargin)
   }
 
-  test("test read from customized catalog") {
+  test("query with customized catalog name") {
+    var result = sql(s"SELECT name, age FROM $testTable")
+    checkAnswer(result, Seq(Row("Hello", 30)))
+  }
 
-    val result = spark.sql(s"SELECT name, age FROM $testTable")
+  test("query without catalog name") {
+    sql("use mycatalog")
+    assert(sql("SHOW CATALOGS").collect === Array(Row("mycatalog")))
 
-    checkAnswer(result, Seq(Row("Hello", 30)))
+    checkAnswer(sql(s"SELECT name, age FROM $testTableWithoutCatalog"), Seq(Row("Hello", 30)))
   }
 }