PlanetScale offers three-way merge for schema changes in its database model, making it simpler and safer to collaborate on schema changes. This is similar to Git's three-way merge concept but has a different implementation. The process involves creating a deployment request, which generates a semantic diff of the changes made between the main branch (production) and the developer's branch. Three-way merge compares these two branches using the main branch as a base and determines if there are conflicts, overlaps, or no impact from one another. This allows for more efficient collaboration and reduces friction in deploying schema changes to production, while also providing early warnings of potential conflicts. PlanetScale disregards index ordering and considers identical or partial overlap between diffs to further reduce developer friction.