What's not a "living system"? You can update RDBMSes much more cleanly and reliably than almost all other software. Stored procedures (in a variety of languages

What's not a "living system"? You can update RDBMSes much more cleanly and reliably than almost all other software. Stored procedures (in a variety of languages) and the like do not necessitate changes to your data schema and the data that ends up in your schema belongs there, regardless of how its produced. That is a data design issue. Being able to roll forward and back with code and data (including an updated schema) that is synchronised and works is a huge win. In most places where I've worked with serious RDBMS systems developers have no access whatsoever to production. The fact that this isn't the case universally illustrates the strength of these RDBMS approaches.