Good question. What are you trying to change in the data? It may be more appropriate to come up with another editing process for it.
In my shop, we can use FileManager to edit large datasets, but it does "window" them which can get tricky. It basically loads all the records it can at once, then lets you work with them.
I'd bet you a small coffee though that you'd be better off doing it in batch, using a tool designed for the job.