diff --git a/amber/src/main/python/core/storage/iceberg/iceberg_utils.py b/amber/src/main/python/core/storage/iceberg/iceberg_utils.py
index f973c72fe81..844ef3e00ff 100644
--- a/amber/src/main/python/core/storage/iceberg/iceberg_utils.py
+++ b/amber/src/main/python/core/storage/iceberg/iceberg_utils.py
@@ -148,7 +148,7 @@ def create_postgres_catalog(
         catalog_name,
         **{
             "uri": f"postgresql+pg8000://{username}:{password}@{uri_without_scheme}",
-            "warehouse": f"file://{warehouse_path}",
+            "warehouse": warehouse_path,
         },
     )
 
diff --git a/amber/src/main/python/core/storage/iceberg/test_iceberg_utils_catalog.py b/amber/src/main/python/core/storage/iceberg/test_iceberg_utils_catalog.py
new file mode 100644
index 00000000000..902829d44c4
--- /dev/null
+++ b/amber/src/main/python/core/storage/iceberg/test_iceberg_utils_catalog.py
@@ -0,0 +1,98 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+from unittest.mock import patch
+
+from core.storage.iceberg import iceberg_utils
+from core.storage.iceberg.iceberg_utils import create_postgres_catalog
+
+
+class TestCreatePostgresCatalog:
+    """
+    Regression tests for `create_postgres_catalog`.
+
+    The Scala side (`IcebergUtil.createPostgresCatalog`) initializes the JDBC
+    catalog with a plain filesystem warehouse path (no URI scheme). PyIceberg
+    persists the `warehouse` property into table metadata, so if the Python
+    side registers the catalog with a `file://`-prefixed value, Iceberg tables
+    written from Python UDFs become unreadable from the Scala/Java engine
+    (and vice versa). These tests pin the Python side to the same plain-path
+    convention used on the Scala side.
+    """
+
+    def test_warehouse_is_passed_without_file_scheme(self):
+        """`warehouse` must be forwarded as-is, without a `file://` prefix."""
+        warehouse_path = "/tmp/texera/iceberg-warehouse"
+
+        with patch.object(iceberg_utils, "SqlCatalog") as mock_sql_catalog:
+            create_postgres_catalog(
+                catalog_name="texera_iceberg",
+                warehouse_path=warehouse_path,
+                uri_without_scheme="localhost:5432/texera_iceberg_catalog",
+                username="texera",
+                password="password",
+            )
+
+        assert mock_sql_catalog.call_count == 1
+        _, kwargs = mock_sql_catalog.call_args
+        assert kwargs["warehouse"] == warehouse_path
+        assert not kwargs["warehouse"].startswith("file://")
+
+    def test_windows_style_warehouse_is_passed_verbatim(self):
+        """
+        The Scala side strips the Windows drive colon (e.g. `C:/x` -> `C/x`)
+        before registering the catalog so PyArrow can parse the path. The
+        Python side should forward whatever it receives verbatim, so the two
+        runtimes agree on the warehouse string stored in Iceberg metadata.
+        """
+        warehouse_path = "C/Users/texera/iceberg-warehouse"
+
+        with patch.object(iceberg_utils, "SqlCatalog") as mock_sql_catalog:
+            create_postgres_catalog(
+                catalog_name="texera_iceberg",
+                warehouse_path=warehouse_path,
+                uri_without_scheme="localhost:5432/texera_iceberg_catalog",
+                username="texera",
+                password="password",
+            )
+
+        _, kwargs = mock_sql_catalog.call_args
+        assert kwargs["warehouse"] == warehouse_path
+        assert "file://" not in kwargs["warehouse"]
+
+    def test_postgres_uri_is_built_with_pg8000_scheme(self):
+        """The JDBC URI should be prefixed with `postgresql+pg8000://` and
+        include credentials; nothing about that should bleed into `warehouse`.
+        """
+        warehouse_path = "/var/lib/texera/warehouse"
+
+        with patch.object(iceberg_utils, "SqlCatalog") as mock_sql_catalog:
+            create_postgres_catalog(
+                catalog_name="texera_iceberg",
+                warehouse_path=warehouse_path,
+                uri_without_scheme="db.internal:5432/texera_iceberg_catalog",
+                username="texera",
+                password="s3cret",
+            )
+
+        args, kwargs = mock_sql_catalog.call_args
+        assert args == ("texera_iceberg",)
+        assert kwargs["uri"] == (
+            "postgresql+pg8000://texera:s3cret@db.internal:5432/texera_iceberg_catalog"
+        )
+        # And warehouse is still the plain path.
+        assert kwargs["warehouse"] == warehouse_path