You and Lazare are right on the money. And the thing with the database is that the code that inserts/updates it has to agree with all the querying code about wh

You and Lazare are right on the money. And the thing with the database is that the code that inserts/updates it has to agree with all the querying code about what the implicit schema should be - but it's implicit and scattered around your code - so on a large team it's very hard for everyone to understand that implicit contract and it's going to be a constant source of production bugs. Schemas don't change that much compared to code, having a strict schema enforced by the database saves you so much time and pain and downtime in the long run.