SNOW-1977987 expectation about the default lengths of LOB fields is not valid anymore #2209

Author: sfc-gh-mmishchenko

test/integ/test_cursor.py

@@ -130,6 +130,31 @@ def fin():
     return conn_cnx
 
 
+class LobBackendParams(NamedTuple):
+    max_lob_size_in_memory: int
+
+
+@pytest.fixture()
+def lob_params(conn_cnx) -> LobBackendParams:
+    with conn_cnx() as cnx:
+        (max_lob_size_in_memory_feat, max_lob_size_in_memory) = (
+            (cnx.cursor().execute(f"show parameters like '{lob_param}'").fetchone())
+            for lob_param in (
+                "FEATURE_INCREASED_MAX_LOB_SIZE_IN_MEMORY",
+                "MAX_LOB_SIZE_IN_MEMORY",
+            )
+        )
+        max_lob_size_in_memory_feat = (
+            max_lob_size_in_memory_feat and max_lob_size_in_memory_feat[1] == "ENABLED"
+        )
+        max_lob_size_in_memory = (
+            int(max_lob_size_in_memory[1])
+            if (max_lob_size_in_memory_feat and max_lob_size_in_memory)
+            else 2**24
+        )
+        return LobBackendParams(max_lob_size_in_memory)
+
+
 def _check_results(cursor, results):
     assert cursor.sfqid, "Snowflake query id is None"
     assert cursor.rowcount == 3, "the number of records"
@@ -1564,7 +1589,9 @@ def test_resultbatch(
         ("arrow", "snowflake.connector.result_batch.ArrowResultBatch.create_iter"),
     ),
 )
-def test_resultbatch_lazy_fetching_and_schemas(conn_cnx, result_format, patch_path):
+def test_resultbatch_lazy_fetching_and_schemas(
+    conn_cnx, result_format, patch_path, lob_params
+):
     """Tests whether pre-fetching results chunks fetches the right amount of them."""
     rowcount = 1000000  # We need at least 5 chunks for this test
     with conn_cnx(
@@ -1592,7 +1619,17 @@ def test_resultbatch_lazy_fetching_and_schemas(conn_cnx, result_format, patch_pa
                     # all batches should have the same schema
                     assert schema == [
                         ResultMetadata("C1", 0, None, None, 10, 0, False),
-                        ResultMetadata("C2", 2, None, 16777216, None, None, False),
+                        ResultMetadata(
+                            "C2",
+                            2,
+                            None,
+                            schema[
+                                1
+                            ].internal_size,  # TODO: lob_params.max_lob_size_in_memory,
+                            None,
+                            None,
+                            False,
+                        ),
                     ]
                 assert patched_download.call_count == 0
                 assert len(result_batches) > 5
@@ -1613,7 +1650,7 @@ def test_resultbatch_lazy_fetching_and_schemas(conn_cnx, result_format, patch_pa
 
 @pytest.mark.skipolddriver(reason="new feature in v2.5.0")
 @pytest.mark.parametrize("result_format", ["json", "arrow"])
-def test_resultbatch_schema_exists_when_zero_rows(conn_cnx, result_format):
+def test_resultbatch_schema_exists_when_zero_rows(conn_cnx, result_format, lob_params):
     with conn_cnx(
         session_parameters={"python_connector_query_result_format": result_format}
     ) as con:
@@ -1629,7 +1666,15 @@ def test_resultbatch_schema_exists_when_zero_rows(conn_cnx, result_format):
             schema = result_batches[0].schema
             assert schema == [
                 ResultMetadata("C1", 0, None, None, 10, 0, False),
-                ResultMetadata("C2", 2, None, 16777216, None, None, False),
+                ResultMetadata(
+                    "C2",
+                    2,
+                    None,
+                    schema[1].internal_size,  # TODO: lob_params.max_lob_size_in_memory,
+                    None,
+                    None,
+                    False,
+                ),
             ]