remove arrow schema cast

Author: kevinjqliu

pyiceberg/table/__init__.py

@@ -484,10 +484,6 @@ def append(self, df: pa.Table, snapshot_properties: Dict[str, str] = EMPTY_DICT)
             )
 
         _check_schema_compatible(self._table.schema(), other_schema=df.schema)
-        # cast if the two schemas are compatible but not equal
-        table_arrow_schema = self._table.schema().as_arrow()
-        if table_arrow_schema != df.schema:
-            df = df.cast(table_arrow_schema)
 
         with self.update_snapshot(snapshot_properties=snapshot_properties).fast_append() as update_snapshot:
             # skip writing data files if the dataframe is empty
@@ -525,10 +521,6 @@ def overwrite(
             raise ValueError("Cannot write to partitioned tables")
 
         _check_schema_compatible(self._table.schema(), other_schema=df.schema)
-        # cast if the two schemas are compatible but not equal
-        table_arrow_schema = self._table.schema().as_arrow()
-        if table_arrow_schema != df.schema:
-            df = df.cast(table_arrow_schema)
 
         with self.update_snapshot(snapshot_properties=snapshot_properties).overwrite() as update_snapshot:
             # skip writing data files if the dataframe is empty