- Real-time: Instead of typical HTTP requests, the Firebase Real-time Database uses data synchronization—every time data changes, any connected device receives that update within milliseconds. Provide collaborative and immersive experiences without thinking about networking code.
- Offline: Firebase apps remain responsive even when offline because the Firebase Real-time Database SDK persists your data to disk. Once connectivity is reestablished, the client device receives any changes it missed, synchronizing it with the current server state.
- Accessible from Client Devices: The Firebase Real-time Database can be accessed directly from a mobile device or web browser; there’s no need for an application server. Security and data validation are available through the Firebase Real-time Database Security Rules, expression-based rules that are executed when data is read or written.
- Scale across multiple Databases: With Firebase Real-time Database on the Blaze pricing plan, you can support your app’s data needs at scale by splitting your data across multiple database instances in the same Firebase project. Streamline authentication with Firebase Authentication on your project and authenticate users across your database instances. Control access to the data in each database with custom Firebase Real-time Database Rules for each database instance.
How does it work?
The Firebase Real-time Database lets you build rich, collaborative applications by allowing secure access to the database directly from client-side code. Data is persisted locally, and even while offline, real-time events continue to fire, giving the end user a responsive experience. When the device regains connection, the Real-time Database synchronizes the local data changes with the remote updates that occurred while the client was offline, merging any conflicts automatically.
The Real-time Database provides a flexible, expression-based rules language, called Firebase Real-time Database Security Rules, to define how your data should be structured and when data can be read from or written to. When integrated with Firebase Authentication, developers can define who has access to what data, and how they can access it. Database API is designed to only allow operations that can be executed quickly.
The Realtime Database is a NoSQL database and as such has different optimizations and functionality compared to a relational database. This enables you to build a great Real-time experience that can serve millions of users without compromising on responsiveness. Because of this, it is important to think about how users need to access your data and then structure it accordingly.
- Integrate the Firebase Real-time Database SDKs
- Quickly include clients via Gradle, CocoaPods, or a script include.
- Create Realtime Database References
- Reference your JSON data, such as “users/user:1234/phone_number” to set data or subscribe to data changes.
3. Set Data and Listen for Changes
- Use these references to write data or subscribe to changes.
- Enable Offline Persistence
- Allow data to be written to the device’s local disk so it can be available while offline.
- Secure your data
- Use Firebase Real-time Database Security Rules to secure your data.
To Store Other types of data:
- Cloud Firestore is a flexible, scalable database for mobile, web, and server development from Firebase and Google Cloud Platform. To learn more about the differences between database options, see Choose a database: Cloud Firestore or Real-time Database.
- Firebase Remote Config stores developer specified key-value pairs to change the behavior and appearance of your app without requiring users to download an update.
- Cloud Storage stores files such as images, videos, and audio as well as other user-generated content.