How to change the database structure in production with long SQL queries?

Question

Software Deployment

It is necessary to change the structure of the database, respectively, to change the data a little. The process will take about 15 minutes. Some queries block the database.
There is a task: it is necessary that the site works while this process is going on.
From what I was offered: to create an exact copy of the site. On it, make all the changes, as it ends, send the web server there. So that there is no difference while the process is in progress, make sure that there is no entry in the database.

Answer 1

like a question from an interview)), but in general create a copy of the table, transfer the changes there, then rename the table