fix: default Python geospatial results to strings

Signed-off-by: Cathleen Yan <58714163+cathleeny@users.noreply.github.com>

Author: cathleeny

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Release History
 
 # Unreleased
-- Add the default-enabled, kernel-only `enable_geospatial_support` connection option. GEOMETRY / GEOGRAPHY results are exposed as `{"srid": int, "wkb": bytes}` values when true or WKT / EWKT strings when false.
+- Add the kernel-only `enable_geospatial_support` connection option (default `False`). GEOMETRY / GEOGRAPHY results are exposed as `{"srid": int, "wkb": bytes}` values when true or WKT / EWKT strings when false.
 - Add the `escape_catalog_name` connection parameter (default `False`) to opt in to escaping unescaped `_` in metadata catalog names on Thrift and kernel connections. Existing escapes and `%` wildcards are preserved.
 
 # 4.6.0 (2026-09-24)

src/databricks/sql/backend/kernel/client.py

@@ -171,7 +171,7 @@ def _kernel_session_accepts_kwarg(name: str) -> bool:
 
 
 def _kernel_geospatial_kwargs(value: bool) -> Dict[str, bool]:
-    """Build the default-enabled native geospatial-support kwarg.
+    """Build the explicit native geospatial-support kwarg.
 
     The value is always passed explicitly so the driver and kernel contracts
     cannot drift. Older kernel wheels do not declare
@@ -283,12 +283,12 @@ def __init__(
         # The kernel binding owns type and range validation.
         self._request_timeout_secs = kwargs.get("request_timeout_secs")
         self._max_connections = kwargs.get("max_connections")
-        # Default-enabled native GEOMETRY / GEOGRAPHY support. True requests
+        # Opt-in native GEOMETRY / GEOGRAPHY support. True requests
         # the canonical Arrow struct and surfaces as ``{"srid": int, "wkb":
         # bytes}`` through pyarrow; False requests WKT / EWKT strings. This is
         # intentionally separate from ``session_configuration``: it is never
         # forwarded to SEA.
-        self._enable_geospatial_support = kwargs.get("enable_geospatial_support", True)
+        self._enable_geospatial_support = kwargs.get("enable_geospatial_support", False)
         # Kernel telemetry phase 7 adds binding/runtime identity and
         # telemetry config kwargs directly to ``databricks_sql_kernel.Session``.
         self._telemetry_options = kwargs.get("telemetry_options") or {}

src/databricks/sql/client.py

@@ -194,7 +194,7 @@ def __init__(
                 decision. This is an intentional divergence from the
                 Thrift/SEA paths, where an explicit ``True`` can still
                 be suppressed by the feature flag.
-            :param enable_geospatial_support: `bool`, optional (default is True)
+            :param enable_geospatial_support: `bool`, optional (default is False)
                 Kernel backend only. Controls the public representation of
                 ``GEOMETRY`` and ``GEOGRAPHY`` result values. ``True`` returns
                 ``{"srid": int, "wkb": bytes}``; ``False`` returns WKT / EWKT

src/databricks/sql/session.py

@@ -332,7 +332,9 @@ def _create_backend(
                 retry_options=kernel_retry_options,
                 request_timeout_secs=kwargs.get("_socket_timeout"),
                 max_connections=kwargs.get("_pool_maxsize") or None,
-                enable_geospatial_support=kwargs.get("enable_geospatial_support", True),
+                enable_geospatial_support=kwargs.get(
+                    "enable_geospatial_support", False
+                ),
                 telemetry_options=kernel_telemetry_options,
                 escape_catalog_name=kwargs.get("escape_catalog_name", False),
             )

tests/unit/test_kernel_client.py

@@ -418,7 +418,7 @@ def fake_session(*, enable_geospatial_support=True, **kw):
     assert captured["enable_geospatial_support"] is enabled
 
 
-def test_open_session_enables_geospatial_support_by_default(monkeypatch):
+def test_open_session_disables_native_geospatial_support_by_default(monkeypatch):
     captured = {}
 
     def fake_session(**kw):
@@ -437,7 +437,7 @@ def fake_session(**kw):
 
     c.open_session(session_configuration=None, catalog=None, schema=None)
 
-    assert captured["enable_geospatial_support"] is True
+    assert captured["enable_geospatial_support"] is False
 
 
 def test_open_session_rejects_explicit_geospatial_option_with_old_kernel(

tests/unit/test_session.py

@@ -877,6 +877,42 @@ def _connect(self, **overrides):
         args.update(overrides)
         return databricks.sql.connect(**args)
 
+    @pytest.mark.parametrize("route", ["explicit", "recovery", "cached"])
+    @pytest.mark.parametrize(
+        "geospatial_kwargs, expected",
+        [
+            pytest.param({}, False, id="default"),
+            pytest.param({"enable_geospatial_support": False}, False, id="disabled"),
+            pytest.param({"enable_geospatial_support": True}, True, id="enabled"),
+        ],
+    )
+    @patch("%s.session.ThriftDatabricksClient" % PACKAGE)
+    def test_kernel_routing_preserves_geospatial_representation(
+        self, mock_thrift, route, geospatial_kwargs, expected
+    ):
+        from databricks.sql.backend import reyden_warehouse_cache
+
+        mock_thrift.return_value.open_session.side_effect = self._reject()
+        if route == "cached":
+            reyden_warehouse_cache.mark_reyden(self.HOST, "wh-reyden")
+        if route == "explicit":
+            geospatial_kwargs = {**geospatial_kwargs, "use_kernel": True}
+
+        with self._fake_kernel() as mock_kernel:
+            conn = self._connect(**geospatial_kwargs)
+            try:
+                assert conn.session.use_kernel is True
+                assert (
+                    mock_kernel.call_args.kwargs["enable_geospatial_support"]
+                    is expected
+                )
+                if route == "recovery":
+                    mock_thrift.return_value.open_session.assert_called_once()
+                else:
+                    mock_thrift.return_value.open_session.assert_not_called()
+            finally:
+                conn.close()
+
     @patch("%s.session.ThriftDatabricksClient" % PACKAGE)
     def test_thrift_rejection_recovers_onto_kernel(self, mock_thrift):
         mock_thrift.return_value.open_session.side_effect = self._reject()