Then perhaps the larger concern is just the overall processing time to perform the task. If the migration is an ALL ABOARD scenario (meaning all the data, all at once), then unless there's a reason for this to take hours, there may not be too much reason to worry about performance, but as the environment hasn't been discussed, we have nothing to go on. Alternatively, you could be migrating in steps, and might have limited windows within which to operate, so you may need to then test such a process and see how long it takes so you can then judge how large the pieces of the migration need to be.