Ask HN: Have you ever changed your DBMS for a site running in production? I've worked for places that write straight SQL & places that use an ORM for all the things. I know one benefit of using an ORM is being able to switch to a different DBMS, but I'm wondering how often that's happened. I've been writing web apps for almost 20 years, and have yet to see it happen. I'm just wondering if anyone has actually done it, and what the reasons were? |
The switch in code was trivial as we were making full use of the Django ORM and the migration script we created was simple as they were both Relational DB's. However most of our time was spend testing and creating fail safes as changing a production DB if done wrong can have dire consequences.
That said, the original reason I encountered for a db abstraction layer (orm or otherwise) was if you were selling software to be hosted on a clients stack. The more dbs you could support the better.
I tend to abhor full ORMs that require layering deep knowledge of the ORM's idioms on top of my existing knowledge of SQL and the underlying SQL implementation. An ORM doesn't magically free me from understanding the actual implementation and the additional overhead often isn't worth it.