Migrating blocks field

[siccifolium]

What is the best approach when I have a collection with a blocks field with a couple of different blocks and at one point in time I need to change the shape/structure of one of the blocks. How do I update the already existing documents which make use of this block type?
So far my approach is to implement a migration file which loops over all documents in a collection and then reads the blocks field and manually iterates through all the blocks and migrates the data. Then the updated document is updated via the payload local api.
Is there a better approach to this problem? Am I overseeing a more obvious solution?
My suggested solutions has some downsides, for example for every migration a new version of the document is created.

[andershermansen]

Depending on your database. If it's mongodb you could write an aggregation pipeline to update the database directly.

https://www.mongodb.com/docs/manual/core/aggregation-pipeline/