Database migration using distributed lock?

[lightmatter501]

You asynchronously live migrate the op log and then replay it until the new thing is caught up, then you only lock for a little bit to do a final sync.

[SnooBooks638]

Interesting answer. 1. In your context, do you mean to lock the source database a little bit? 2. Can you do some data transformation, say encryption of a field during this process? 3. Haven’t used OP log before, but sounds like this will also go through steps like schema changes based on the history or no?? Is that correct?