What is a split-brain?

To illustrate the problem, here's a quick diagram:

Split-brain

We can mitigate this problem by increasing the granularity of our data storage. In Chapter 4, Getting Online, the changes were made at the list level. Thus, two people making changes to the same list while offline would always have their changes conflicting. Thanks to the improvements that we made in Chapter 5, Be Honest about What's Happening, each person would have to make a change to the same description, map coordinate, or image for a conflict to occur.

This is vastly improved. However, when a conflict does occur, how do we resolve it? At its core, there are three basic answers. Either Change A wins, Change B wins, or both exist in perpetuity. In addition, depending on how much the owners and collaborators of a list trust each other, we could either allow a single person to resolve the conflict or require input from every person with edit privileges. Let's look at both of these scenarios...