Thanks for the reply. My question was specifically about the MVCC feature that creates new rows for updates like this. If you're backfilling data into a new column then you'll likely end up creating new rows for the entire table and the space for the old rows will be marked for re-use via auto-vacuuming. Anyway, bloat like this is a big pain for me when make migrations on huge tables. It doesn't sound like this type of bloat cleanup is a goal for pgroll. Regardless, it's always great to have more options in this space. Thanks for your work!