feat: record the namespace a view's unqualified names resolve against

A view outlives the session that declared it, so the namespace path its
query resolved against travels with it, beside the database. Without it
a reader would resolve an unqualified name against its own default and
read a different table.

`ViewDescription` carries `default_namespace_path`; it crosses the wire
as `default_namespace`, a path like `namespace`, absent for the root.

python/python/lancedb/_lancedb.pyi

@@ -170,10 +170,10 @@ class Connection(object):
     ) -> Tuple[str, int, int]: ...
     async def create_view(
         self, name: str, query: str, namespace_path: Optional[List[str]] = None
-    ) -> Tuple[str, List[str], str, str, pa.Schema]: ...
+    ) -> Tuple[str, List[str], str, str, List[str], pa.Schema]: ...
     async def describe_view(
         self, name: str, namespace_path: Optional[List[str]] = None
-    ) -> Tuple[str, List[str], str, str, pa.Schema]: ...
+    ) -> Tuple[str, List[str], str, str, List[str], pa.Schema]: ...
     async def drop_view(
         self, name: str, namespace_path: Optional[List[str]] = None
     ) -> None: ...

python/python/lancedb/db.py

@@ -98,16 +98,24 @@ from .namespace_utils import (
 
 
 def _view_description(
-    described: Tuple[str, List[str], str, str, "pa.Schema"],
+    described: Tuple[str, List[str], str, str, List[str], "pa.Schema"],
 ) -> ViewDescription:
     """Name the fields the binding returns positionally."""
-    name, namespace_path, query, default_database, schema = described
+    (
+        name,
+        namespace_path,
+        query,
+        default_database,
+        default_namespace_path,
+        schema,
+    ) = described
     return ViewDescription(
         name=name,
         query=query,
         default_database=default_database,
         schema=schema,
         namespace_path=namespace_path,
+        default_namespace_path=default_namespace_path,
     )
 
 

python/python/lancedb/view.py

@@ -31,3 +31,10 @@ class ViewDescription:
     """The schema the defining query resolved to when the view was created."""
     namespace_path: List[str] = field(default_factory=list)
     """The namespace holding the view; empty is the root namespace."""
+    default_namespace_path: List[str] = field(default_factory=list)
+    """The namespace path those unqualified names resolve against.
+
+    Recorded with the view because it outlives the session that declared it: a
+    reader resolving the query against its own default namespace could read a
+    different table than the view was defined over.
+    """

python/python/tests/test_remote_db.py

@@ -2766,6 +2766,7 @@ def test_view_crud_addresses_its_own_routes():
                 "namespace": ["analytics"],
                 "query": "SELECT name FROM people",
                 "default_database": "dev",
+                "default_namespace": ["analytics"],
                 "schema": {
                     "fields": [
                         {"name": "name", "nullable": True, "type": {"type": "utf8"}}
@@ -2785,6 +2786,7 @@ def test_view_crud_addresses_its_own_routes():
         assert view.namespace_path == ["analytics"]
         assert view.query == "SELECT name FROM people"
         assert view.default_database == "dev"
+        assert view.default_namespace_path == ["analytics"]
         assert view.schema == pa.schema([pa.field("name", pa.utf8(), nullable=True)])
 
         described = db.describe_view("adults", namespace_path=["analytics"])

python/src/connection.rs

@@ -106,7 +106,7 @@ fn parse_default_namespace_path(path: Option<Bound<'_, PyAny>>) -> PyResult<Vec<
 
 /// A view description on its way to Python: name, namespace, query, default
 /// database, and the schema as pyarrow renders it.
-type PyViewDescription = (String, Vec<String>, String, String, Py<PyAny>);
+type PyViewDescription = (String, Vec<String>, String, String, Vec<String>, Py<PyAny>);
 
 /// A view description as a plain tuple, with the schema converted to the
 /// pyarrow schema the caller would get from any other lancedb API. The Python
@@ -120,6 +120,7 @@ fn view_description_to_py(view: lancedb::view::ViewDescription) -> PyResult<PyVi
             view.namespace_path,
             view.query,
             view.default_database,
+            view.default_namespace_path,
             schema,
         ))
     })