public static Schema changeFieldNameToLowercase(Schema schema) {
    Types.StructType struct =
        TypeUtil.visit(
                schema.asStruct(), new ChangeFieldName(ChangeFieldName.ChangeType.TO_LOWERCASE))
            .asStructType();
    return new Schema(struct.fields(), schema.identifierFieldIds());
  }
Change the field name in schema to lowercase.

@param schema The original schema to change
@return An new schema with lowercase field name
amoro-format-mixed/amoro-mixed-hive/src/main/java/org/apache/amoro/hive/utils/HiveSchemaUtil.java