Mobile computing devices (e.g., smartphones and PDAs) store and share data over a mobile network, or a database which is actually stored by the mobile device. This could be a list of contacts, price information, distance travelled, or any other information.[1]
Many applications require the ability to download information from an information repository and operate on this information even when out of range or disconnected. An example of this is your contacts and calendar on the phone. In this scenario, a user would require access to update information from files in the home directories on a server or customer records from a database. This type of access and work load generated by such users is different from the traditional workloads seen in client–server systems of today.
Mobile databases are not used solely for the revision of company contacts and calendars, but used in a number of industries.
This is in database theory known as "replication", and good mobile database system should provide tools for automatic replication that takes into account that others may have modified the same data as you while you were away, and not just the last update is kept, but also supports "merge" of variants.
Commercially available mobile databases include those shown on this comparison chart.
| Name | Developer | Type | Sync Central | Sync P2P | Description | License | |
|---|---|---|---|---|---|---|---|
| Couchbase Lite | Couchbase | JSON Document | Yes | Yes | Embedded/portable database, can synchronize with multiple stationary database and/or mobile devices. | Apache 2.0 License | |
| InterBase | Embarcadero Technologies | Relational | Dependent | Dependent | IoT embedded/portable database, can synchronize with multiple stationary database and/or mobile devices | Proprietary | |
| ObjectBox | ObjectBox Inc. | Object Database | Dependent | ? | Edge database for local data persistence | Apache 2.0 / MIT | |
| Realm | MongoDB Inc. | Object Database | Dependent | No | Portable local database, has a synchronized mode that synchronizes (real-time) with stationary database | Core Apache 2.0 License, Sync Proprietary | |
| SQL Anywhere | Sybase iAnywhere | Relational | Dependent | No | Embedded/portable database, can synchronize with stationary database | Proprietary | |
| DB2 Everyplace | IBM | Relational | Dependent | No | Portable, can synchronize with stationary database | Proprietary EULA | |
| SQL Server Compact | Microsoft | Relational | No | No | Small-footprint embedded/portable database for Microsoft Windows mobile devices and desktops, supports synchronization with Microsoft SQL Server | Proprietary | |
| SQL Server Express | Microsoft | Relational | No | No | Embedded database, free download | Proprietary | |
| Oracle Database Lite | Oracle Corporation | Relational | No | No | Portable, can synchronize with stationary database | Proprietary | |
| SQLite | D. Richard Hipp | Relational | No | No | C programming library | Public domain | |
| SQLBase | Gupta Technologies LLC of Redwood Shores, California | No | No | Proprietary | |||
| Sparksee | Sparsity Technologies | Graph Database | No | No | Graph database written in C++. | Proprietary |