fix: identify missing blob row IDs in batch errors

python/python/lancedb/table.py

@@ -1937,6 +1937,8 @@ class Table(ABC):
         ``row_ids`` may be a list, an integer Arrow array or chunked array,
         or a query table with row ids. ``_rowid`` values stay valid after
         compaction when the table has stable row ids.
+        One missing or deleted row ID rejects the entire batch; no partial
+        results are returned.
 
         Convenience for small payloads. For large values use
         :meth:`fetch_blob_files`.
@@ -1958,6 +1960,8 @@ class Table(ABC):
 
         ``_rowid`` values stay valid after compaction when the table has stable
         row ids.
+        One missing or deleted row ID rejects the entire batch; no partial
+        results are returned.
 
         Row IDs can be obtained from a query with ``with_row_id(True)``. This
         API is currently supported only by local tables.
@@ -1979,6 +1983,8 @@ class Table(ABC):
 
         ``_rowid`` values stay valid after compaction when the table has stable
         row ids.
+        One missing or deleted row ID rejects the entire batch; no partial
+        handles are returned.
         """
 
     @abstractmethod

python/python/tests/test_blob.py

@@ -74,15 +74,19 @@ def _assert_missing_blob_row_ids(exc_info):
 
 
 def _assert_fetch_apis_reject_missing_row_ids(table, row_ids):
+    expected = f"first missing row ids: [{row_ids[0]}]"
     with pytest.raises(ValueError) as exc_info:
         table.fetch_blobs("image", row_ids)
     _assert_missing_blob_row_ids(exc_info)
+    assert expected in str(exc_info.value)
     with pytest.raises(ValueError) as exc_info:
         table.fetch_blob_files("image", row_ids)
     _assert_missing_blob_row_ids(exc_info)
+    assert expected in str(exc_info.value)
     with pytest.raises(ValueError) as exc_info:
         table.fetch_blob_ranges("image", [(row_id, 0, 1) for row_id in row_ids])
     _assert_missing_blob_row_ids(exc_info)
+    assert expected in str(exc_info.value)
 
 
 def test_blob_factory_declares_v2_field():