Question 1

How do I encrypt a Realm database in Swift?

Accepted Answer

Generate a random 64-byte key using SecRandomCopyBytes, add it to Realm.Configuration with the encryptionKey parameter, and open the realm with that config. This encrypts data both on disk and in memory, as shown in the code example with Dog queries.

Question 2

Is Realm better than Core Data for new iOS projects?

Accepted Answer

Realm offers a simpler, object-oriented API and built-in reactive updates with live objects, reducing boilerplate. However, Core Data is more deeply integrated with Apple's ecosystem and has broader third-party tooling. The choice depends on whether you prioritize ease of use over native framework adherence.

Question 3

How to use Realm with SwiftUI for a list that updates automatically?

Accepted Answer

Use the @ObservedResults property wrapper on your Realm object type in your SwiftUI view, as demonstrated in the ContactsView example. The list will automatically refresh when data changes, and you can bind actions like append or remove directly to UI elements.

Question 4

Can Realm handle background threading for database writes?

Accepted Answer

Yes, but it requires careful management: write transactions must be performed on the thread where the realm was opened, and objects cannot be passed between threads directly. Use thread-safe references or dispatch queues to avoid crashes, as noted in documentation about multithreading limitations.

Question 5

How to migrate from SQLite to Realm in an existing app?

Accepted Answer

You'll need to export data from SQLite, transform it to match your Realm object models, and import it into a new Realm file. Realm provides migration blocks for schema changes, but cross-database migration requires custom scripting and can be error-prone for complex datasets.

Question 6

Does Realm's live objects feature impact app performance?

Accepted Answer

Live objects use notification systems that are efficient for typical mobile use, but observing many objects or frequent updates can increase memory and CPU usage. It's best to limit observations to necessary scopes and clean up tokens to avoid leaks, as hinted in the observe example.

Realm

What is Realm?

Overview

Use Cases

Best For

Related Projects

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Open Source Alternative To

Frequently Asked Questions