Android Room vs Realm: What are the differences?

Introduction

Android Room and Realm are both popular database libraries for Android development. They provide an easy way to handle database operations and eliminate the need for writing raw SQL queries. However, there are several key differences between these two libraries. In this article, we will explore and compare the main differences between Android Room and Realm.

1. Architecture

Android Room is based on the SQLite database engine and follows the architecture components guidelines. It uses annotations to generate the necessary code for creating and handling SQLite databases. Realm, on the other hand, is a NoSQL database, which means it does not use tables and SQL queries. It stores data as objects directly within its own format.

2. Performance

When it comes to performance, Realm is generally faster than Android Room. Since Realm does not use SQL queries or SQLite, it can optimize operations and provide faster data access and manipulation. Android Room, being based on SQLite, has some overhead associated with it, which can affect performance in certain scenarios.

3. Real-time Updates

Realm supports real-time updates out of the box. It has a feature called Live Objects, which allows automatic notifications when data changes. This means that any changes made to the Realm database will be immediately reflected in the app without the need for manual refresh or reload. Android Room, on the other hand, does not provide built-in real-time updates.

4. Cross-platform Support

Realm has excellent cross-platform support and can be used not only in Android but also in iOS, React Native, Xamarin, and other platforms. This makes it a versatile choice for projects that require multi-platform development. Android Room, on the other hand, is specific to Android and does not have official support for other platforms.

5. Data Migration

Android Room provides built-in support for database migrations. It has a Migration class that allows developers to define how the database should be migrated when the schema changes. This makes it easy to handle schema changes without losing data. Realm, on the other hand, does not provide a built-in migration mechanism. Data migration in Realm requires writing custom code to handle the migration process.

6. Offline Support

Realm provides powerful offline support through its synchronization feature. It allows users to work with data even when the device is not connected to the internet. Realm can synchronize data automatically when the device goes online. Android Room, on the other hand, does not have built-in offline support. Offline data handling needs to be implemented manually.

Summary

In summary, the key differences between Android Room and Realm are their architecture, performance, real-time update support, cross-platform compatibility, data migration capabilities, and offline support options.