diff --git a/docarray/array/storage/base/backend.py b/docarray/array/storage/base/backend.py
index 0fcb2416df0..8caace91e54 100644
--- a/docarray/array/storage/base/backend.py
+++ b/docarray/array/storage/base/backend.py
@@ -22,7 +22,9 @@ def _init_storage(
     ):
         self._load_offset2ids()
 
-    def _init_subindices(self, *args, **kwargs):
+    def _init_subindices(
+        self, _docs: Optional['DocumentArraySourceType'] = None, *args, **kwargs
+    ):
         self._subindices = {}
         subindex_configs = kwargs.get('subindex_configs', None)
         if subindex_configs:
@@ -39,7 +41,12 @@ def _init_subindices(self, *args, **kwargs):
                     config, config_subindex, config_joined, name
                 )
                 self._subindices[name] = self.__class__(config=config_joined)
-                self._subindices[name].extend(self.traverse_flat(name[1:]))
+                if _docs:
+                    from docarray import DocumentArray
+
+                    self._subindices[name].extend(
+                        DocumentArray(_docs).traverse_flat(name[1:])
+                    )
 
     @abstractmethod
     def _ensure_unique_config(
diff --git a/tests/unit/array/test_backend_configuration.py b/tests/unit/array/test_backend_configuration.py
index cec6326c4eb..8255375e6d2 100644
--- a/tests/unit/array/test_backend_configuration.py
+++ b/tests/unit/array/test_backend_configuration.py
@@ -1,7 +1,20 @@
+import os
+import random
+
 import pytest
 import requests
 
-from docarray import DocumentArray, Document
+from docarray import Document, DocumentArray, dataclass
+from docarray.typing import Image, Text
+
+
+@dataclass
+class MyDocument:
+    image: Image
+    paragraph: Text
+
+
+cur_dir = os.path.dirname(os.path.abspath(__file__))
 
 
 def test_weaviate_hnsw(start_storage):
@@ -138,3 +151,50 @@ def test_cast_columns_qdrant(start_storage, type_da, type_column, request):
     index.extend(docs)
 
     assert len(index) == N
+
+
+def test_random_subindices_config():
+    database_index = random.randint(0, 100)
+    database_name = "jina" + str(database_index) + ".db"
+    table_index = random.randint(0, 100)
+    table_name = "test" + str(table_index)
+    subindice_image_index = random.randint(0, 100)
+    subindice_image_name = "test" + str(subindice_image_index)
+    subindice_paragraph_index = random.randint(0, 100)
+    subindice_paragraph_name = "test" + str(subindice_paragraph_index)
+    sqlite3_config = {'connection': database_name, 'table_name': table_name}
+
+    common_subindex_config = {
+        '@.[image]': {'connection': database_name, 'table_name': subindice_image_name},
+        '@.[paragraph]': {
+            'connection': database_name,
+            'table_name': subindice_paragraph_name,
+        },
+    }
+    # extend with Documents, including embeddings
+    _docs = [
+        (
+            MyDocument(
+                image=os.path.join(cur_dir, '../document/toydata/test.png'),
+                paragraph='hello world',
+            )
+        )
+    ]
+
+    da = DocumentArray(
+        storage='sqlite',  # use SQLite as vector database
+        config=sqlite3_config,
+        subindex_configs=common_subindex_config,  # set up subindices for image and description
+    )
+    da.summary()
+
+    for item in _docs:
+        d = Document(item)
+        da.append(d)
+
+    da = DocumentArray(
+        storage='sqlite',  # use SQLite as vector database
+        config=sqlite3_config,
+        subindex_configs=common_subindex_config,  # set up subindices for image and description
+    )
+    da.summary()