diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/aws/delta/AwsS3DeltaReaderFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/aws/delta/AwsS3DeltaReaderFactory.java
index 8dc820b..d29cd40 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/aws/delta/AwsS3DeltaReaderFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/aws/delta/AwsS3DeltaReaderFactory.java
@@ -91,7 +91,7 @@
             throws AlgebricksException, HyracksDataException {
         this.configuration = configuration;
         Configuration conf = new Configuration();
-        configurationBuilder(configuration, conf);
+        applyConfiguration(configuration, conf);
         String tableMetadataPath = S3Constants.HADOOP_S3_PROTOCOL + "://"
                 + configuration.get(ExternalDataConstants.CONTAINER_NAME_FIELD_NAME) + '/'
                 + configuration.get(ExternalDataConstants.DEFINITION_FIELD_NAME);
@@ -189,7 +189,7 @@
         partitionWorkLoadsBasedOnSize.addAll(workloadQueue);
     }
 
-    public static void configurationBuilder(Map<String, String> configuration, Configuration conf) {
+    public static void applyConfiguration(Map<String, String> configuration, Configuration conf) {
         conf.set(S3Constants.HADOOP_ACCESS_KEY_ID, configuration.get(S3Constants.ACCESS_KEY_ID_FIELD_NAME));
         conf.set(S3Constants.HADOOP_SECRET_ACCESS_KEY, configuration.get(S3Constants.SECRET_ACCESS_KEY_FIELD_NAME));
         if (configuration.get(S3Constants.SESSION_TOKEN_FIELD_NAME) != null) {
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/util/ExternalDataUtils.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/util/ExternalDataUtils.java
index 19c1979..12ce22d 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/util/ExternalDataUtils.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/util/ExternalDataUtils.java
@@ -519,11 +519,16 @@
         String tableMetadataPath = null;
         if (configuration.get(ExternalDataConstants.KEY_EXTERNAL_SOURCE_TYPE)
                 .equals(ExternalDataConstants.KEY_ADAPTER_NAME_AWS_S3)) {
-            AwsS3DeltaReaderFactory.configurationBuilder(configuration, conf);
+            AwsS3DeltaReaderFactory.applyConfiguration(configuration, conf);
             tableMetadataPath = S3Constants.HADOOP_S3_PROTOCOL + "://"
                     + configuration.get(ExternalDataConstants.CONTAINER_NAME_FIELD_NAME) + '/'
                     + configuration.get(ExternalDataConstants.DEFINITION_FIELD_NAME);
+        } else {
+            throw new CompilationException(ErrorCode.EXTERNAL_SOURCE_ERROR,
+                    "Delta format is not supported for the external source type: "
+                            + configuration.get(ExternalDataConstants.KEY_EXTERNAL_SOURCE_TYPE));
         }
+
         Engine engine = DefaultEngine.create(conf);
         io.delta.kernel.Table table = io.delta.kernel.Table.forPath(engine, tableMetadataPath);
         try {