diff --git a/plugin/src/main/java/org/opensearch/ml/sdkclient/DDBOpenSearchClient.java b/plugin/src/main/java/org/opensearch/ml/sdkclient/DDBOpenSearchClient.java
index e4ed9dc019..4c8819f2cd 100644
--- a/plugin/src/main/java/org/opensearch/ml/sdkclient/DDBOpenSearchClient.java
+++ b/plugin/src/main/java/org/opensearch/ml/sdkclient/DDBOpenSearchClient.java
@@ -233,29 +233,13 @@ public CompletionStage<UpdateDataObjectResponse> updateDataObjectAsync(
                 String source = Strings.toString(MediaTypeRegistry.JSON, request.dataObject());
                 JsonNode jsonNode = OBJECT_MAPPER.readTree(source);
                 Map<String, AttributeValue> updateItem = JsonTransformer.convertJsonObjectToDDBAttributeMap(jsonNode);
-                updateItem.remove(HASH_KEY);
+                updateItem.remove(TENANT_ID);
                 updateItem.remove(RANGE_KEY);
                 Map<String, AttributeValue> updateKey = new HashMap<>();
                 updateKey.put(HASH_KEY, AttributeValue.builder().s(tenantId).build());
                 updateKey.put(RANGE_KEY, AttributeValue.builder().s(request.id()).build());
-                UpdateItemRequest.Builder updateItemRequestBuilder = UpdateItemRequest.builder().tableName(request.index()).key(updateKey);
-                Map<String, String> expressionAttributeNames = new HashMap<>();
-                expressionAttributeNames.put("#seqNo", SEQ_NO_KEY);
-                expressionAttributeNames.put("#source", SOURCE);
-                Map<String, AttributeValue> expressionAttributeValues = new HashMap<>();
-                expressionAttributeValues.put(":incr", AttributeValue.builder().n("1").build());
-                expressionAttributeValues.put(":source", AttributeValue.builder().m(updateItem).build());
-                updateItemRequestBuilder.updateExpression("SET #seqNo = #seqNo + :incr, #source = :source ");
-                if (request.ifSeqNo() != null) {
-                    // Get current document version and put in attribute map. Ignore primary term on DDB.
-                    updateItemRequestBuilder.conditionExpression("#seqNo = :currentSeqNo");
-                    expressionAttributeValues.put(":currentSeqNo", AttributeValue.builder().n(Long.toString(request.ifSeqNo())).build());
-                }
-                updateItemRequestBuilder
-                    .expressionAttributeNames(expressionAttributeNames)
-                    .expressionAttributeValues(expressionAttributeValues);
-                UpdateItemRequest updateItemRequest = updateItemRequestBuilder.build();
-                Long sequenceNumber = updateItemWithRetryOnConflict(updateItemRequest, request);
+
+                Long sequenceNumber = updateItemWithRetryOnConflict(updateKey, updateItem, request);
                 String simulatedUpdateResponse = simulateOpenSearchResponse(
                     request.index(),
                     request.id(),
@@ -275,10 +259,41 @@ public CompletionStage<UpdateDataObjectResponse> updateDataObjectAsync(
         }), executor);
     }
 
-    private Long updateItemWithRetryOnConflict(UpdateItemRequest updateItemRequest, UpdateDataObjectRequest request) {
+    private Long updateItemWithRetryOnConflict(
+        Map<String, AttributeValue> updateKey,
+        Map<String, AttributeValue> updateItem,
+        UpdateDataObjectRequest request
+    ) {
         int retriesRemaining = request.retryOnConflict();
         do {
             try {
+                UpdateItemRequest.Builder updateItemRequestBuilder = UpdateItemRequest.builder().tableName(request.index()).key(updateKey);
+                updateItemRequestBuilder.updateExpression("SET #seqNo = #seqNo + :incr, #source = :source ");
+                // Get current document version and put in attribute map. Ignore primary term on DDB.
+                updateItemRequestBuilder.conditionExpression("#seqNo = :currentSeqNo");
+                Map<String, String> expressionAttributeNames = new HashMap<>();
+                expressionAttributeNames.put("#seqNo", SEQ_NO_KEY);
+                expressionAttributeNames.put("#source", SOURCE);
+                Map<String, AttributeValue> expressionAttributeValues = new HashMap<>();
+                expressionAttributeValues.put(":incr", AttributeValue.builder().n("1").build());
+                // Fetch current item and extract data object
+                Map<String, AttributeValue> currentItem = dynamoDbClient
+                    .getItem(GetItemRequest.builder().tableName(request.index()).key(updateKey).build())
+                    .item();
+                Map<String, AttributeValue> dataObject = new HashMap<>(currentItem.get(SOURCE).m());
+                // Update existing with changes
+                dataObject.putAll(updateItem);
+                expressionAttributeValues.put(":source", AttributeValue.builder().m(dataObject).build());
+                // Use seqNo from the object we got to make sure we're updating the same thing
+                if (request.ifSeqNo() != null) {
+                    expressionAttributeValues.put(":currentSeqNo", AttributeValue.builder().n(Long.toString(request.ifSeqNo())).build());
+                } else {
+                    expressionAttributeValues.put(":currentSeqNo", currentItem.get(SEQ_NO_KEY));
+                }
+                updateItemRequestBuilder
+                    .expressionAttributeNames(expressionAttributeNames)
+                    .expressionAttributeValues(expressionAttributeValues);
+                UpdateItemRequest updateItemRequest = updateItemRequestBuilder.build();
                 UpdateItemResponse updateItemResponse = dynamoDbClient.updateItem(updateItemRequest);
                 if (updateItemResponse != null
                     && updateItemResponse.attributes() != null