Storing data

Overview

There are several ways you can store, share, and manage data for your apps:

Data storage approach	Description and API
SQLite database	Store data in relational databases with the Database API.
File system	Store data in files and folders with the FileConnection API.
Persistent store	Save objects across smartphone restarts with the PersistentStore API.
Runtime store	Save objects nonpersistently, which is useful for sharing data between applications and creating system-wide singletons, with the RuntimeStore API.
Record store	Store data in the MIDP Record Management System with the RMS API.

Here's a comparison of the data storage approaches:

Features	SQLite database	File system	Persistent store	Runtime store	Record store
Data format	Relational database file	Any	Java object	Java object	Serialized
Storage locations	External media card, built-in media storage	Application storage, external media card, built-in media storage	Application storage	Application storage	Application storage
Maximum storage limit	Size of partitions the user has access to	Size of partitions the user has access to	Available application storage	Available application storage	Differs according to BlackBerry Device Software version
BlackBerry Device Software support	5.0 or later	4.2 or later	All	3.6 or later	All
Persists across device restarts	Yes	Yes	Yes	No	Yes
Applications can share data	Yes	Yes	Yes	Yes	Yes

When choosing a data storage approach, keep the following in mind:

The file system and SQLite databases are typically the most efficient storage location for large, read-only files such as videos or large graphics.
Memory on wireless devices can be very limited, so you should consider not storing all data on the smartphone. BlackBerry smartphones are frequently connected so your application can access data when needed. In many cases, the best approach is to store data across smartphone restarts only for data that is frequently accessed.
When you consider where to store essential data, keep in mind that microSD cards can be removed.
There is more latency in writing to application storage than there is in reading from it. For example, reading from the persistent store is relatively fast while commits are relatively slow.
The file system and record store are standards-based approaches, while the persistent store and runtime store are specific to BlackBerry smartphones. If you want your application to run on other Java MEcompatible devices, you should consider a standards-based approach.

Storage locations

Different BlackBerry smartphones support different places to store data. The following storage locations are available, depending on the smartphone model:

Application storage	This storage location is internal to the smartphone. It contains the operating system, the BlackBerry Java Virtual Machine, and an internal file system. Application storage is also called flash memory and on-board memory. Application storage is the only place on a BlackBerry smartphone from which apps can be run. All BlackBerry smartphones have application storage.
External media card storage	This storage location is a microSD card that BlackBerry smartphone users can insert to extend the amount of storage on their smartphones. It is optional and removable. A FAT file system is mounted on the media card. MicroSD cards are supported on all smartphones running BlackBerry Device Software 4.2 or later, with the exception of the BlackBerry 8700 Series.
Built-in media storage	This storage location is an embedded multimedia card called eMMC. It is not removable. A FAT file system is mounted on the built-in media card. Built-in media storage is also called internal media memory and on-board device memory. Built-in media storage is included on some BlackBerry smartphone models.

Storing data

Overview

Storage locations

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