Fix VECTOR workaround: use nullable inner field

Author: BohuTANG

python/databend_udf/udf.py

@@ -1410,7 +1410,7 @@ def _type_str_to_arrow_field_inner(type_str: str) -> pa.Field:
         # This is a workaround because Databend UDF client might not support FixedSizeList yet.
         return pa.field(
             "",
-            pa.list_(pa.field("item", pa.float32(), nullable=False)),
+            pa.list_(pa.field("item", pa.float32(), nullable=True)),
             nullable=False,
             metadata={
                 EXTENSION_KEY: ARROW_EXT_TYPE_VECTOR,

python/pyproject.toml

@@ -7,7 +7,7 @@ classifiers = [
 description = "Databend UDF Server"
 license = { text = "Apache-2.0" }
 name = "databend-udf"
-version = "0.2.14"
+version = "0.2.15"
 readme = "README.md"
 requires-python = ">=3.7"
 dependencies = [

python/tests/test_vector_type.py

@@ -40,7 +40,7 @@ def test_vector_type_formatting():
     # Test that a List with VECTOR metadata is formatted as VECTOR(N)
     field = pa.field(
         "",
-        pa.list_(pa.field("item", pa.float32(), nullable=False)),
+        pa.list_(pa.field("item", pa.float32(), nullable=True)),
         nullable=False,
         metadata={
             b"Extension": b"Vector",
@@ -55,7 +55,7 @@ def test_vector_input_processing():
     # Input processing should handle List (which is what VECTOR is physically)
     field = pa.field(
         "",
-        pa.list_(pa.field("item", pa.float32(), nullable=False)),
+        pa.list_(pa.field("item", pa.float32(), nullable=True)),
         nullable=False,
         metadata={
             b"Extension": b"Vector",
@@ -74,7 +74,7 @@ def test_vector_output_processing():
     # Output processing should handle List
     field = pa.field(
         "",
-        pa.list_(pa.field("item", pa.float32(), nullable=False)),
+        pa.list_(pa.field("item", pa.float32(), nullable=True)),
         nullable=False,
         metadata={
             b"Extension": b"Vector",