How does Realm DB differ from Room Database for Android Studio?

Introduction to Realm DB in Android with Kotlin

When developing Android applications, choosing the right database solution is crucial for performance, ease of use, and maintainability. Realm DB is an increasingly popular mobile database that stands out for its speed and simplicity. In this blog, we’ll explore what Realm DB is, how it differs from Room Database, and why it might be the better choice for your next Android project.

What is Realm DB?

Realm DB is a mobile database solution designed to provide high performance and ease of use. Unlike traditional databases, Realm is not built on top of SQLite. Instead, it uses its own persistence engine, which allows for faster read and write operations. Realm’s main selling points are its simplicity, speed, and cross-platform capabilities.

How is Realm Different from Room Database?

Room Database, part of the Android Jetpack library, is an abstraction layer over SQLite. While both Room and Realm serve the same purpose — storing and managing data — they differ significantly in their approach and features.

Key Differences

Architecture

• Room: Built on top of SQLite, requiring SQL queries and annotations to map data to objects.
• Realm: Uses its own engine, with data objects directly mapped to Realm models, avoiding the need for SQL.

Performance

• Room: Performance is generally good, but complex queries and large data sets can impact speed due to SQLite’s limitations.
• Realm: Known for superior performance, especially with large datasets and complex queries, thanks to its efficient data handling and zero-copy architecture.

Ease of Use

• Room: Requires writing boilerplate code, including DAOs (Data Access Objects) and SQL queries.
• Realm: Simplifies data operations with less boilerplate code. Models are simple classes, and data operations are straightforward.

Data Handling

• Room: Data is fetched as plain objects and can be manipulated outside the database context.
• Realm: Data is live and reactive, meaning any changes in the database are immediately reflected in the UI without additional code.

Threading

• Room: Requires explicit handling of threading, often needing LiveData or RxJava to manage async operations.
• Realm: Built-in support for multithreading and reactive programming, making it easier to manage data across different threads.

Why Use Realm Over Room?

1. Simplicity and Productivity

Realm’s straightforward API allows developers to get up and running quickly. You don’t need to write extensive boilerplate code or complex SQL queries. This makes development faster and reduces the potential for bugs.

2. Performance

For applications that require handling large datasets or complex queries, Realm offers better performance. Its underlying engine is optimized for speed, making it a suitable choice for performance-critical applications.

3. Reactive Architecture

With Realm, your data is always up-to-date. Changes in the database are instantly available in the UI, simplifying the implementation of reactive architectures. This is particularly useful for real-time applications such as chat apps or live data feeds.

4. Cross-Platform Support

Realm supports both Android and iOS, enabling developers to share the same database schema across platforms. This can be a significant advantage for teams building cross-platform applications.

Conclusion

While Room Database is a solid choice for many applications, Realm DB stands out for its performance, simplicity, and powerful features. If you’re looking to streamline your development process and build high-performance mobile applications, Realm is definitely worth considering. In the next sections of this blog, we’ll dive into setting up Realm in an Android project, defining models, and performing basic CRUD operations using Kotlin.

Stay tuned and happy coding!