chore: clean it

VectorStore cannot actually migrate to or from qdrant yet. _init_backend_store constructs QdrantStore without connecting or selecting a collection, so reads raise a Collection not initialized error, and the facade store_vectors dispatches only to add/add_vectors while QdrantStore exposes insert_vectors, so writes raise NotImplementedError.

Both are pre-existing facade gaps that nothing had exposed, since migrate previously only allowed faiss/sqlite/pgvector. Adding qdrant to the allowlist claimed support that does not work end to end, so it is removed along with the dimension inference that only fires for backends missing a .dimension attribute. Tracked separately; this PR keeps just the iter_all primitive.

semantica/vector_store/pinecone_store.py

@@ -299,6 +299,44 @@ class PineconeSearch:
         )
 
 
+def _pinecone_listed_ids(response: Any) -> List[str]:
+    """Extract vector IDs from a list_paginated() response.
+
+    Accepts record objects, bare id strings and dicts, since what listing
+    returns has changed across pinecone SDK major versions.
+    """
+    records = getattr(response, "vectors", None)
+    if records is None and isinstance(response, dict):
+        records = response.get("vectors")
+
+    ids: List[str] = []
+    for record in records or []:
+        if isinstance(record, str):
+            ids.append(record)
+        elif isinstance(record, dict):
+            if record.get("id") is not None:
+                ids.append(record["id"])
+        else:
+            record_id = getattr(record, "id", None)
+            if record_id is not None:
+                ids.append(record_id)
+    return ids
+
+
+def _pinecone_next_token(response: Any) -> Optional[str]:
+    """Return the continuation token, or None when the listing is exhausted."""
+    pagination = getattr(response, "pagination", None)
+    if pagination is None and isinstance(response, dict):
+        pagination = response.get("pagination")
+    if pagination is None:
+        return None
+
+    token = getattr(pagination, "next", None)
+    if token is None and isinstance(pagination, dict):
+        token = pagination.get("next")
+    return token or None
+
+
 class PineconeStore:
     """
     Pinecone store for vector storage and similarity search.
@@ -735,6 +773,84 @@ class PineconeStore:
             self.logger.warning(f"Failed to filter Pinecone vectors by metadata: {e}")
             return []
 
+    def iter_all(self, batch_size: int = 500, namespace: str = ""):
+        """
+        Iterate over every stored vector by listing IDs then fetching them.
+
+        Paginates with an opaque continuation token, which is why this exists
+        instead of scan_vectors(offset, limit): the token for page N cannot be
+        constructed without walking there.
+
+        Needs two calls per page, unlike the other backends, because listing
+        returns IDs only. Both calls are namespace scoped and must agree, and
+        listing covers one namespace rather than the whole index.
+
+        Args:
+            batch_size: IDs to request per list_paginated() call
+            namespace: Namespace to enumerate (default: the default namespace)
+
+        Yields:
+            Result dicts with 'id', 'metadata', and 'vector', in listing order
+
+        Raises:
+            ProcessingError: If the index is not initialized, if the installed
+                SDK does not expose list_paginated(), or if the listing stops
+                advancing.
+        """
+        if self.index is None or not PINECONE_AVAILABLE:
+            raise ProcessingError(
+                "Index not initialized. Call create_index() or get_index() first."
+            )
+
+        # list_paginated() rather than list(): list() is an auto-paging
+        # iterator in current SDKs but reads as plain id lists in older
+        # examples. Threading the token explicitly is version-agnostic.
+        list_paginated = getattr(self.index.index, "list_paginated", None)
+        if not callable(list_paginated):
+            raise ProcessingError(
+                "This pinecone SDK version does not expose Index.list_paginated(), "
+                "which full enumeration requires."
+            )
+
+        token = None
+        while True:
+            kwargs: Dict[str, Any] = {"limit": batch_size, "namespace": namespace}
+            if token is not None:
+                kwargs["pagination_token"] = token
+
+            response = list_paginated(**kwargs)
+            vector_ids = _pinecone_listed_ids(response)
+            if not vector_ids:
+                return
+
+            fetched = self.index.fetch_vectors(vector_ids, namespace=namespace)
+            vectors = fetched.get("vectors") or {}
+
+            for vector_id in vector_ids:
+                entry = vectors.get(vector_id)
+                if entry is None:
+                    # fetch() omits ids it cannot find: deleted since listing.
+                    continue
+                values = entry.get("values")
+                yield {
+                    "id": vector_id,
+                    "metadata": entry.get("metadata") or {},
+                    "vector": np.array(values) if values is not None else None,
+                }
+
+            next_token = _pinecone_next_token(response)
+            if not next_token:
+                return
+            if next_token == token:
+                # Distinct from exhaustion above: a partial scan here would be
+                # indistinguishable from a complete one.
+                raise ProcessingError(
+                    "Pinecone returned the same pagination token twice, so the "
+                    "listing is not advancing. Refusing to return a truncated "
+                    "scan."
+                )
+            token = next_token
+
     def fetch_vectors(
         self, vector_ids: List[str], namespace: str = "", **options
     ) -> Dict[str, Any]:

semantica/vector_store/qdrant_store.py

@@ -604,6 +604,62 @@ class QdrantStore:
             self.logger.warning(f"Failed to scroll Qdrant points by metadata filter: {e}")
             return []
 
+    def iter_all(self, batch_size: int = 500):
+        """
+        Iterate over every stored point using Qdrant's native scroll cursor.
+
+        Qdrant paginates by point-ID cursor, not by row offset, so this is
+        exposed instead of scan_vectors(offset, limit). An integer passed to
+        scroll()'s offset is a point ID rather than a rank, so there is no way
+        to seek to "the Nth record" without walking from the start.
+        VectorStore.iter_vectors() prefers this method when it is present.
+
+        Assumes a single unnamed vector per point, matching how insert_vectors()
+        writes them and how get_vector() reads them back. Collections configured
+        with named or multi-vectors are not handled here.
+
+        Args:
+            batch_size: Points to request per scroll call
+
+        Yields:
+            Result dicts with 'id', 'metadata', and 'vector', in scroll order
+
+        Raises:
+            ProcessingError: If the collection or client is not initialized.
+                Errors are raised rather than swallowed because a scan that
+                silently yields nothing is indistinguishable from an empty
+                source, which would let a caller such as `store migrate`
+                report success having copied nothing (issue #1083).
+        """
+        if self.collection is None or self.client is None or not QDRANT_AVAILABLE:
+            raise ProcessingError(
+                "Collection not initialized. Call create_collection() or get_collection() first."
+            )
+
+        next_offset = None
+        while True:
+            records, next_offset = self.client.scroll(
+                collection_name=self.collection.collection_name,
+                limit=batch_size,
+                offset=next_offset,
+                with_payload=True,
+                with_vectors=True,
+            )
+
+            for rec in records:
+                yield {
+                    "id": str(rec.id),
+                    "metadata": rec.payload or {},
+                    "vector": np.array(rec.vector) if rec.vector is not None else None,
+                }
+
+            # The final page can carry records while already reporting no next
+            # cursor, so those records are yielded above before stopping here.
+            # Calling scroll() again with offset=None would restart from the
+            # beginning rather than continue past the end.
+            if next_offset is None or not records:
+                return
+
     def delete_vectors(
         self, point_ids: List[Union[str, int]], **options
     ) -> Dict[str, Any]:

semantica/vector_store/vector_store.py

@@ -867,12 +867,25 @@ class VectorStore:
         """
         Iterate over every stored vector, one page at a time.
 
+        Backends whose native pagination is cursor based (Qdrant, Pinecone,
+        Milvus, Weaviate) cannot honestly implement the positional
+        scan_vectors(offset, limit) contract, so they expose iter_all()
+        instead and it is preferred here when present. Backends with real
+        positional access (inmemory, FAISS, SQLite-vec, PgVector) fall
+        through to the offset loop below.
+
         Args:
-            batch_size: Number of vectors to fetch per underlying scan_vectors() call
+            batch_size: Number of vectors to fetch per underlying call
 
         Yields:
             Result dicts with 'id', 'metadata', and 'vector', in scan order
         """
+        if self.backend != "inmemory" and self._backend_store is not None:
+            iter_all = getattr(self._backend_store, "iter_all", None)
+            if callable(iter_all):
+                yield from iter_all(batch_size=batch_size)
+                return
+
         offset = 0
         while True:
             page = self.scan_vectors(offset=offset, limit=batch_size)

tests/vector_store/test_pinecone_store.py

@@ -249,6 +249,166 @@ class TestPineconeIndex(unittest.TestCase):
         mock_index.query.assert_called_once()
 
 
+class TestPineconeIterAll(unittest.TestCase):
+    """PineconeStore.iter_all() list-then-fetch enumeration."""
+
+    def _page(self, ids, next_token):
+        """Stand-in for a list_paginated() response."""
+        response = MagicMock()
+        response.vectors = [MagicMock(id=vector_id) for vector_id in ids]
+        response.pagination = MagicMock(next=next_token)
+        return response
+
+    def _store(self, pages, fetch_results):
+        store = PineconeStore()
+        wrapper = MagicMock()
+        raw_index = MagicMock()
+        raw_index.list_paginated.side_effect = list(pages)
+        wrapper.index = raw_index
+        wrapper.fetch_vectors.side_effect = list(fetch_results)
+        store.index = wrapper
+        return store, wrapper, raw_index
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_threads_pagination_token_across_pages(self):
+        store, _, raw_index = self._store(
+            [self._page(["a", "b"], "token-1"), self._page(["c"], None)],
+            [
+                {"vectors": {"a": {"values": [0.1], "metadata": {}},
+                             "b": {"values": [0.2], "metadata": {}}}},
+                {"vectors": {"c": {"values": [0.3], "metadata": {}}}},
+            ],
+        )
+
+        result = list(store.iter_all(batch_size=2))
+
+        self.assertEqual([item["id"] for item in result], ["a", "b", "c"])
+        calls = raw_index.list_paginated.call_args_list
+        self.assertNotIn("pagination_token", calls[0][1])
+        self.assertEqual(calls[1][1]["pagination_token"], "token-1")
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_hydrates_listed_ids_with_a_fetch(self):
+        """Listing returns ids only, so each page needs a fetch()."""
+        store, wrapper, _ = self._store(
+            [self._page(["a"], None)],
+            [{"vectors": {"a": {"values": [0.1, 0.2], "metadata": {"tag": "x"}}}}],
+        )
+
+        item = list(store.iter_all())[0]
+
+        self.assertEqual(item["id"], "a")
+        self.assertEqual(item["metadata"], {"tag": "x"})
+        np.testing.assert_allclose(item["vector"], np.array([0.1, 0.2]))
+        wrapper.fetch_vectors.assert_called_once_with(["a"], namespace="")
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_list_and_fetch_use_the_same_namespace(self):
+        store, wrapper, raw_index = self._store(
+            [self._page(["a"], None)],
+            [{"vectors": {"a": {"values": [0.1], "metadata": {}}}}],
+        )
+
+        list(store.iter_all(namespace="prod"))
+
+        self.assertEqual(raw_index.list_paginated.call_args[1]["namespace"], "prod")
+        wrapper.fetch_vectors.assert_called_once_with(["a"], namespace="prod")
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_skips_ids_deleted_between_list_and_fetch(self):
+        """fetch() omits ids it cannot find rather than returning blanks."""
+        store, _, _ = self._store(
+            [self._page(["a", "gone"], None)],
+            [{"vectors": {"a": {"values": [0.1], "metadata": {}}}}],
+        )
+
+        result = list(store.iter_all())
+
+        self.assertEqual([item["id"] for item in result], ["a"])
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_raises_when_pagination_token_repeats(self):
+        """A stalled token must not loop forever, nor quietly return a partial
+        scan that reads as a complete one."""
+        store, _, raw_index = self._store(
+            [self._page(["a"], "same"), self._page(["b"], "same")],
+            [
+                {"vectors": {"a": {"values": [0.1], "metadata": {}}}},
+                {"vectors": {"b": {"values": [0.2], "metadata": {}}}},
+            ],
+        )
+
+        with self.assertRaises(ProcessingError):
+            list(store.iter_all())
+
+        self.assertEqual(raw_index.list_paginated.call_count, 2)
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_empty_listing_yields_nothing_without_fetching(self):
+        store, wrapper, _ = self._store([self._page([], None)], [])
+
+        self.assertEqual(list(store.iter_all()), [])
+        wrapper.fetch_vectors.assert_not_called()
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_accepts_plain_string_ids_from_listing(self):
+        """SDK generations differ on what listing yields."""
+        store, _, _ = self._store(
+            [self._page([], None)],
+            [{"vectors": {"a": {"values": [0.1], "metadata": {}}}}],
+        )
+        response = MagicMock()
+        response.vectors = ["a"]
+        response.pagination = MagicMock(next=None)
+        store.index.index.list_paginated.side_effect = [response]
+
+        self.assertEqual([item["id"] for item in store.iter_all()], ["a"])
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_handles_missing_values_and_metadata(self):
+        store, _, _ = self._store(
+            [self._page(["a"], None)],
+            [{"vectors": {"a": {"values": None, "metadata": None}}}],
+        )
+
+        item = list(store.iter_all())[0]
+
+        self.assertIsNone(item["vector"])
+        self.assertEqual(item["metadata"], {})
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_raises_when_list_paginated_unavailable(self):
+        store = PineconeStore()
+        wrapper = MagicMock()
+        wrapper.index = MagicMock(spec=["query", "fetch"])
+        store.index = wrapper
+
+        with self.assertRaises(ProcessingError):
+            list(store.iter_all())
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_raises_when_index_not_initialized(self):
+        """Must fail loudly: an empty scan reads the same as an empty source."""
+        with self.assertRaises(ProcessingError):
+            list(PineconeStore().iter_all())
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', False)
+    def test_raises_when_pinecone_unavailable(self):
+        store = PineconeStore()
+        store.index = MagicMock()
+
+        with self.assertRaises(ProcessingError):
+            list(store.iter_all())
+
+    @patch('semantica.vector_store.pinecone_store.PINECONE_AVAILABLE', True)
+    def test_propagates_listing_errors(self):
+        store, _, raw_index = self._store([], [])
+        raw_index.list_paginated.side_effect = RuntimeError("connection reset")
+
+        with self.assertRaises(RuntimeError):
+            list(store.iter_all())
+
+
 if __name__ == '__main__':
     print("DEBUG: Starting unittest.main()")
     unittest.main()

tests/vector_store/test_qdrant_store.py

@@ -0,0 +1,152 @@
+"""Tests for QdrantStore.iter_all() cursor enumeration.
+
+Qdrant is not installed in this environment, so these drive the real
+QdrantStore against a MagicMock standing in for the qdrant_client, following
+the pattern already used for qdrant in test_backend_metadata_filtering.py.
+"""
+
+from unittest.mock import MagicMock, patch
+
+import numpy as np
+import pytest
+
+from semantica.utils.exceptions import ProcessingError
+from semantica.vector_store.qdrant_store import QdrantStore
+
+
+def _record(point_id, payload=None, vector=None):
+    """Build a stand-in for a qdrant_client Record."""
+    rec = MagicMock()
+    rec.id = point_id
+    rec.payload = payload
+    rec.vector = vector
+    return rec
+
+
+def _store_with_scroll(*pages):
+    """QdrantStore whose client.scroll() returns the given (records, cursor) pages."""
+    store = QdrantStore()
+    store.client = MagicMock()
+    store.client.scroll.side_effect = list(pages)
+    store.collection = MagicMock()
+    store.collection.collection_name = "test_collection"
+    return store
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_threads_cursor_across_pages():
+    """The next call must continue from the previous page's next_page_offset."""
+    store = _store_with_scroll(
+        ([_record(1), _record(2)], "cursor-1"),
+        ([_record(3)], None),
+    )
+
+    result = list(store.iter_all(batch_size=2))
+
+    assert [item["id"] for item in result] == ["1", "2", "3"]
+    calls = store.client.scroll.call_args_list
+    assert len(calls) == 2
+    assert calls[0][1]["offset"] is None
+    assert calls[0][1]["limit"] == 2
+    assert calls[1][1]["offset"] == "cursor-1"
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_yields_final_page_that_reports_no_next_cursor():
+    """Qdrant can return records and a null cursor on the same page.
+
+    Those records must still be yielded. Treating a null cursor as "stop
+    before this page" would silently drop the tail of every scan.
+    """
+    store = _store_with_scroll(([_record(1), _record(2)], None))
+
+    result = list(store.iter_all(batch_size=10))
+
+    assert [item["id"] for item in result] == ["1", "2"]
+    assert store.client.scroll.call_count == 1
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_converts_records_to_the_shared_result_shape():
+    store = _store_with_scroll(
+        ([_record(7, payload={"tag": "x"}, vector=[0.1, 0.2, 0.3])], None),
+    )
+
+    item = list(store.iter_all())[0]
+
+    assert item["id"] == "7"
+    assert item["metadata"] == {"tag": "x"}
+    np.testing.assert_allclose(item["vector"], np.array([0.1, 0.2, 0.3]))
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_handles_missing_payload_and_vector():
+    store = _store_with_scroll(([_record(1, payload=None, vector=None)], None))
+
+    item = list(store.iter_all())[0]
+
+    assert item["metadata"] == {}
+    assert item["vector"] is None
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_empty_collection_yields_nothing():
+    store = _store_with_scroll(([], None))
+
+    assert list(store.iter_all()) == []
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_stops_on_empty_page_even_with_a_cursor():
+    """Defensive: an empty page ends the scan rather than looping forever."""
+    store = _store_with_scroll(([], "cursor-that-never-clears"))
+
+    assert list(store.iter_all()) == []
+    assert store.client.scroll.call_count == 1
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_raises_when_collection_not_initialized():
+    """Must fail loudly, not yield nothing.
+
+    An empty scan is indistinguishable from an empty source, which would let
+    `store migrate` report success having copied nothing (issue #1083).
+    """
+    store = QdrantStore()
+
+    with pytest.raises(ProcessingError, match="Collection not initialized"):
+        list(store.iter_all())
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", False)
+def test_iter_all_raises_when_qdrant_unavailable():
+    store = QdrantStore()
+    store.client = MagicMock()
+    store.collection = MagicMock()
+
+    with pytest.raises(ProcessingError):
+        list(store.iter_all())
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_propagates_scroll_errors():
+    store = QdrantStore()
+    store.client = MagicMock()
+    store.client.scroll.side_effect = RuntimeError("connection reset")
+    store.collection = MagicMock()
+    store.collection.collection_name = "test_collection"
+
+    with pytest.raises(RuntimeError, match="connection reset"):
+        list(store.iter_all())
+
+
+@patch("semantica.vector_store.qdrant_store.QDRANT_AVAILABLE", True)
+def test_iter_all_requests_payload_and_vectors():
+    store = _store_with_scroll(([], None))
+
+    list(store.iter_all())
+
+    kwargs = store.client.scroll.call_args[1]
+    assert kwargs["with_payload"] is True
+    assert kwargs["with_vectors"] is True
+    assert kwargs["collection_name"] == "test_collection"

tests/vector_store/test_vector_manager_persistent.py

@@ -26,6 +26,7 @@ from unittest.mock import MagicMock, patch
 
 import numpy as np
 
+from semantica.utils.exceptions import ProcessingError
 from semantica.vector_store.vector_store import VectorStore, VectorManager
 
 
@@ -138,6 +139,38 @@ class _NonScanningBackendStore:
     """Fake persistent backend store without any scan capability."""
 
 
+class _IterAllBackendStore:
+    """Fake cursor-based backend store exposing iter_all() but not scan_vectors().
+
+    Mirrors qdrant/pinecone/milvus/weaviate, which cannot honour a positional
+    offset and therefore expose native iteration instead.
+    """
+
+    def __init__(self, items):
+        self._items = items
+        self.batch_sizes = []
+
+    def iter_all(self, batch_size=500):
+        self.batch_sizes.append(batch_size)
+        for item in self._items:
+            yield item
+
+    def scan_vectors(self, offset=0, limit=100):
+        raise AssertionError("scan_vectors() must not be called when iter_all() exists")
+
+
+class _MisShapedIterAllBackendStore:
+    """Backend store whose ``iter_all`` attribute is not callable."""
+
+    iter_all = 42  # plain attribute, not a method
+
+    def __init__(self, items):
+        self._items = items
+
+    def scan_vectors(self, offset=0, limit=100):
+        return self._items[offset:offset + limit]
+
+
 class VectorStoreScanVectorsTests(unittest.TestCase):
     """VectorStore.scan_vectors() / iter_vectors() backend-agnostic accessors."""
 
@@ -192,6 +225,81 @@ class VectorStoreScanVectorsTests(unittest.TestCase):
         self.assertEqual(list(store.iter_vectors(batch_size=2)), [])
 
 
+# ---------------------------------------------------------------------------
+# VectorStore.iter_vectors() preference for a native iter_all()
+# ---------------------------------------------------------------------------
+
+class VectorStoreIterAllDispatchTests(unittest.TestCase):
+    """iter_vectors() prefers a backend's native iter_all() when present.
+
+    Cursor-based backends cannot implement scan_vectors(offset, limit)
+    honestly, so they expose iter_all() instead and iter_vectors() routes to
+    it rather than walking offsets.
+    """
+
+    def _persistent_store(self, backend_store, backend_name="qdrant"):
+        store = VectorStore(backend="inmemory", dimension=2)
+        store.backend = backend_name
+        store._backend_store = backend_store
+        return store
+
+    def test_iter_vectors_uses_iter_all_when_available(self):
+        items = [
+            {"id": "a", "vector": None, "metadata": {"n": 1}},
+            {"id": "b", "vector": None, "metadata": {"n": 2}},
+        ]
+        backend = _IterAllBackendStore(items)
+        store = self._persistent_store(backend)
+
+        self.assertEqual(list(store.iter_vectors(batch_size=7)), items)
+
+    def test_iter_vectors_forwards_batch_size_to_iter_all(self):
+        backend = _IterAllBackendStore([])
+        store = self._persistent_store(backend)
+
+        list(store.iter_vectors(batch_size=32))
+
+        self.assertEqual(backend.batch_sizes, [32])
+
+    def test_iter_vectors_falls_back_to_scan_vectors_without_iter_all(self):
+        items = [{"id": "a", "vector": None, "metadata": {}}]
+        store = self._persistent_store(_ScanningBackendStore(items))
+
+        self.assertEqual(list(store.iter_vectors(batch_size=2)), items)
+
+    def test_iter_vectors_falls_back_when_iter_all_not_callable(self):
+        # A mis-shaped adapter exposing a non-callable ``iter_all`` must not be
+        # invoked; the offset path still has to work. Mirrors the count()
+        # precedent in _MisShapedBackendStore.
+        items = [{"id": "a", "vector": None, "metadata": {}}]
+        store = self._persistent_store(_MisShapedIterAllBackendStore(items))
+
+        self.assertEqual(list(store.iter_vectors(batch_size=2)), items)
+
+    def test_iter_vectors_inmemory_ignores_iter_all(self):
+        store = VectorStore(backend="inmemory", dimension=2)
+        store.store_vectors([np.array([1.0, 0.0])], [{"type": "a"}])
+        store._backend_store = _IterAllBackendStore([{"id": "wrong"}])
+
+        collected = list(store.iter_vectors(batch_size=2))
+
+        self.assertEqual([item["metadata"] for item in collected], [{"type": "a"}])
+
+    def test_iter_vectors_propagates_iter_all_errors(self):
+        # A scan that silently yields nothing is indistinguishable from an
+        # empty source, which would let `store migrate` report success having
+        # copied nothing (issue #1083).
+        class _FailingIterAll:
+            def iter_all(self, batch_size=500):
+                raise ProcessingError("backend unreachable")
+                yield  # pragma: no cover - makes this a generator
+
+        store = self._persistent_store(_FailingIterAll())
+
+        with self.assertRaises(ProcessingError):
+            list(store.iter_vectors(batch_size=2))
+
+
 # ---------------------------------------------------------------------------
 # VectorManager tests — inmemory backend
 # ---------------------------------------------------------------------------