> This might cause the whole table to be locked and copied in SQL That was indeed the case in the past, but not so much anymore except for certain situations.

> This might cause the whole table to be locked and copied in SQL That was indeed the case in the past, but not so much anymore except for certain situations. MySQL, for example, has had support for in-place table alterations for a while [1]. I've used it in production and it works very well IME. [1] https://dev.mysql.com/doc/refman/8.0/en/innodb-online-ddl.html https://dev.mysql.com/doc/refman/8.0/en/innodb-online-ddl.ht...