Android is a persistent form of data storage for mobile devices, allowing applications to continue functioning even when the device is disconnected due to its local storage capabilities.
SQLite is included in the SDK, making it the most commonly used database due to its integration within the platform.
What to Look for in a Mobile Database?
While databases generally offer data storage, querying, and processing capabilities, not all databases are the same.
Before looking at types of databases, consider the following points:
What type of data are you storing?
Structured/unstructured data or large files? Should the data be shared among users or stored only on the device?
How will you access your data?
Do you need complex queries to merge data from multiple sources?
Hosting Method:
How will users interact with your application’s data?
Do users expect real-time collaboration without noticeable delays? Should data be shared between users and devices?
Different Types of Android Databases:
Having learned what to consider in a database, let’s look at some types of Android databases.
They are broadly categorized into three: relational, key-value, and object-oriented.
Relational Database:
Uses keys to establish relationships between tables and shared columns. The most common example is SQLite, found within the Android SDK.
Key-Value Database:
Utilizes a key for storing information in a single value mapping. Often used in Android databases for storing things like user preferences; an example would be Shared Preferences for Android.
Object-Oriented Database:
Works with complex data objects similar to object-oriented programming languages. Allows for fast queries with complex data. Code in the database is often simpler because the code and objects in the database are close to each other.
Example: Realm is an object-oriented database.
Considerations for Hosting and Functionality of a Database:
Local Storage:
The most significant feature in mobile apps is storing data locally for offline use. Continuously available data enhances user experience, although mobile devices can have inconsistent network connections due to their portability.
Cloud Data Storage:
Many mobile apps and devices necessitate data sharing, which isn’t supported by local storage solutions. Hence, developers need to store application data on a server, leading to cloud data storage.
There are various advantages to a cloud database. For instance, MongoDB.
However, the driver used to communicate with the database always requires network access, which can make the experience suboptimal for mobile usage scenarios where device connectivity is sporadic.
Server:
You may prefer to maintain your data by using your servers or data centers. However, consider a self-hosted and mobile-friendly database solution. Yet, it will still require internet access for access.
Keeping the Database on the Device or in the Cloud:
Two options handle connection issues and provide real-time data sharing. These are cloud databases and local databases.
