With market giants like Walmart, Bloomberg, and SoundCloud adopting React Native, it has received the most support among all cross-platform app development frameworks.

Because of its status as the ‘future of mobile apps’, there is a lot of curiosity among developers about the right choice of database for building React Native apps.

As apps grow in complexity, it increases the demands on database performance. To decide a database for your React Native app, the app development team must consider several factors. 

Factors that affect React Native database selection

1. Data complexity

Key-value storage is the default option for many client-side and server-side scripting languages. Both keys and values have to be serialized into strings, either by the programmer or internally by the library. Serialization can put serious dents on the performance of your application, which operates in a limited resources environment of a smartphone.

To help you store more complex data than key-value pairs, such as objects and full documents, select a database that provides complex data types.

2. Ease of use 

If it takes you 20 lines of code to write a simple CRUD operation, that database should be the last choice for any application. Not only will this database make coding too complicated, but it will also affect the performance of the database itself heavily. Processing so many lines of code will slow down your app down.

So don’t use a database with an advanced functionality if it comes at the cost of your app’s user experience or the release velocity.

3. Synchronization of offline data

If you are building a simple offline app that doesn’t offer multi-user collaboration, the database can get away with simplified synchronization. These kinds of apps can just sync with the server whenever they get an internet connection.

With collaboration as the central feature of the app, the synchronization demands on the database get more complex. Apps like Trello can’t show two users different versions of the same project/document/shared resource. So your database must allow perfect synchronization even when it’s running on patchy connections.

4. Concurrency and handling of data conflicts

The more collaboration features you introduce into your app, the higher is the possibility of data conflicts. Look for databases that explicitly share their conflict-handling policy on their website or repository pages. An example of poor conflict resolution policy would sound like ‘last write wins’.

Read through their documents to get more aware of how the database handles conflicts and synchronization. Go through the trade-offs they make and what would be the potential effect of them on your app. 

5. Memory management

Poor memory handling practices of the databases can cause frequent app crashes. Compaction is a proactive process of memory management where data or documents that are never going to be used again are cleared off the memory.

This is similar to ‘garbage collection’ in programming and it ensures there is a good amount of free memory available for your app.

Related: Flutter vs React Native

Options for database in a React Native app

There are a lot of options for a local database with React Native. Most of them are free and open-source, while some have paid variants for enterprise apps.

1. Realm

What makes Realm different is that its an object-oriented database, not a relational database. This means 10-times faster, query-free usage of the database. 

Realm is customized for iOS, Android, and JavaScript. It has its own database engine with support for complex data types for offline and real-time applications. 

The background synchronization services in Realm make servicing of local requests possible. User interaction requests are saved offline and synched when the device goes online. This was demonstrated with its Draw app. 

Custom security protocols for each of the different device platforms is also one of the strengths of Realm.

2. Firebase 

Firebase is a Google-owned, cloud-hosted database that lets you host and sync data across multiple devices in real-time. This feature makes Firebase perfectly suitable for multi-user, hyper-collaborative apps with high availability requirements. 

With its minimal-setup cross-platform API, you can create serverless apps that access the Firebase database very easily. 

Firebase takes care of data security as it transports all data over SSL (Secure Socket Layer). This is similar to serving your website over HTTPS instead of HTTP. 

3. SQLite

SQLite is the “lite” version of the original relational database SQL. It built specifically for the resource-constricted environment of a mobile device and has a much easier setup. 

SQLite being a basic relational database, meaning that synchronization and concurrency are left to the developer. Anything beyond basic CRUD apps will need some major work to design database access protocols. 

For offline persistence with SQLite, you will need to work with the react-native-sqlite-storage plugin. Security in SQLite is implemented through SQLLite Encryption Extension (SEE) or plugins like SQLiteCrypt and SQLCipher

Selecting a React Native Database for your offline app

React Native is arguably the best technology to build your next cross-platform Android and iOS app. To select the right database for your next mobile app and to integrate it with your offline app requires strategic planning and highly skilled developers. 

With over 10 years of experience in designing and developing native and cross-platform mobile apps, Arkenea – a mobile application development company, is best positioned to help you design and develop your next React Native mobile app. Contact us for a free consultation.