Automatic vs Manual Schema Migration for Mid-Session Updates

When updating a small Android application using Realm, maintaining session continuity during a schema migration is critical to avoid runtime crashes. The goal is to determine the safest approach for applying schema changes without interrupting active user sessions.

Automatic migrations simplify deployment by handling schema changes at runtime, but they may trigger immediate schema checks that block the main thread or cause incompatibility if the existing Realm file does not align with the new model. Conversely, manual migration scripts provide explicit control over data transformations and versioning, though they introduce higher development overhead and a risk of version mismatch if the release is not perfectly synchronized.

Given these constraints, there is uncertainty regarding which strategy minimizes the risk of crashes during in-flight user sessions when a schema update is pushed.

• Does automatic migration provide sufficient stability for mid-session updates in small-scale applications?
• Under what specific conditions does manual migration outperform automatic migration in preventing runtime crashes during a version transition?