IBM Cloudscape

Cloudscape is a relational database management engine implemented as a Java class library. Applications use the JDBC API to access data managed by the Cloudscape engine.

Embedded

The database engine is embeddable. This means that rather than running as a separate process, the database engine software can be part of the application so that the application and the database engine run in the same JVM. With an embedded database engine, the application uses the JDBC API to access the database. The embedded JDBC driver transfers data to and from the database engine without the need for network communication. Whether or not it is embedded, the database engine supports multiple simultaneous connections and access from multiple application threads.
Figure 1. Cloudscape embedded in an application

Network Server

It is also possible to deploy Cloudscape as a traditional client/server database server. To accomplish this, use Cloudscape embedded in a server framework (that is, a piece of software that can accept and process network communication). Cloudscape includes a Network Server, but you can also run Cloudscape in a server framework of your choice.
Figure 2. Cloudscape acts as a client/server DBMS within a server framework

Easy Integration

It is just as easy to embed Cloudscape inside a Java Web server, such as IBM WebSphere® Application Server. Figure 3 shows Cloudscape embedded in a Java Web server, with clients accessing the database through Hypertext Transfer Protocol (HTTP) requests to servlets.
Figure 3. Cloudscape embedded in a Web server

Data Persistence

Cloudscape provides persistence of data by storing data in disk files. A Cloudscape engine can manage one or more database files, but each database file can only be accessed by a single Cloudscape engine. In a client/server configuration, the engine provides multi-user access to the databases under its control. All threads that access the database do so through the database engine.

The data in the database disk files is stored in a portable format, so that databases can be easily transported from machine to machine regardless of the CPU architecture of each machine. For example, you can directly copy a Cloudscape database you developed on a Linux machine to a Windows machine -- or even to a small device running J2ME/CDC/FP. Cloudscape can also handle data files on read-only media. These characteristics make it easy to download Cloudscape applications together with their database or run them from a CD-ROM. The combination of portable database formats and the pure Java DBMS engine makes it possible to send a data-centric application anywhere, either on media or over a network.
Figure 4. Thread access to Cloudscape

Flexibility

Cloudscape provides a great deal of flexibility for system designers. Each Cloudscape instance can manage multiple databases, the databases can live on various media, and there's nothing to stop the application from connecting to other DBMS systems.
Figure 5. Flexible application architecture