You want to run a transaction in production and you're unsure about the impact because it might take a lock and block other transactions for some time. In that

You want to run a transaction in production and you're unsure about the impact because it might take a lock and block other transactions for some time. In that case you may want to spin up a separate database with fake data and test it there first. You could create a new database and restore a production backup instead of using fake data but that might not be allowed or require some kind of approval due to rules protecting the privacy of customers or employees.