> But I think the more complicated of a transformation you need, the less of a difference there is -- once you start writing a lot of code it doesn't matter if you are modifying a static schema or a dynamic one.
I agree with your general points but disagree with this. Since SQL provides excellent tools for set operations and integrity constraints even very complex migrations are simpler if you have SQL + a schema. SQL features like temporary tables, window functions, inserts using a select as source, CTEs, all help out when doing the really tricky transformations.
Th exception is of course if you have millions of rows of data which you need to do a complex migration for. Then I do not think it ever can be easy, schema or not.
I agree with your general points but disagree with this. Since SQL provides excellent tools for set operations and integrity constraints even very complex migrations are simpler if you have SQL + a schema. SQL features like temporary tables, window functions, inserts using a select as source, CTEs, all help out when doing the really tricky transformations.
Th exception is of course if you have millions of rows of data which you need to do a complex migration for. Then I do not think it ever can be easy, schema or not.