Renaming column in MariaDB 10.0.24/MariaDB 10.0.21/MariaDB 10.0.23-log is doing table copy

Hi Everyone !

I recently discovered that doing table's column renaming in MariaDB Versions like MariaDB 10.0.24/MariaDB 10.0.21/MariaDB do copy tmp table operation however in MySQL 5.6.28, The same doesn't happen and executes in mili seconds.

executed query : alter table table1 change column_name new_column_name varchar(255) not null;

Ideally this operation shouldn't take any time but on mentioned versions, This is causing complete table copy like operation. Please check attached snapshot for better understanding.

FYI : Both servers are having same amount of data in the table and charset/collation are also same at both. I've tried it on other versions of Mariadb like 10.0.24 and 10.0.21 however, copy operation is happening at these as well.