Building Analytical Applications

Java programming language

Java is the language of the Internet, and also the language of OLAP applications. Using Java, an application developer can write a standalone application or an applet, which is a program that can be included in an HTML page and executed in a browser. As an object-oriented, platform-independent, network-based, and secure language, Java is fast superseding C++ and Visual Basic as the language of choice for application developers:

• Object oriented. Java allows application developers to focus on the data and methods of manipulating that data, rather than on abstract procedures; the programmer defines the desired object rather than the steps needed to create that object. Almost everything in Java is defined as an object.

• Platform independent. The Java compiler creates byte code that is interpreted at runtime by the Java Virtual Machine (JVM). As the result, the same software can run on all Windows, Unix, and Macintosh platforms where the JVM has been installed. All major browsers have the JVM built in.

• Network based. Java was designed to work over a network, which allows Java programs to handle remote resources as easily as local resources.

• Secure. Java code is either trusted or untrusted, and access to system resources is determined by this characteristic. Local code is trusted to have full access to system resources, but downloaded remote code (that is, an applet) is not trusted.

  The Java "sandbox" security model provides a very restricted environment for untrusted code. For example, untrusted Java code cannot read to or write from files on the local file system, run programs, load libraries, define native method calls, or make network connections except to the originating host computer. A security manager determines the system resources that an applet can access. However, a signed applet, which identifies itself as being from a trusted source, has full access to system resources the same as local code.

JavaBeans for business intelligence

JavaBeans are the building blocks of application development. They are reusable pieces of Java code that can be assembled quickly into an application.

The BI Beans provide the basic building blocks for an OLAP application: Connecting to a database; authenticating user credentials; selecting and fetching data; and displaying the data in a variety of tabular and graphical formats. Using the BI Beans, you can create applications with a common "look and feel," enabling users to gain expertise quickly in the new product.

The Oracle OLAP API

The Oracle OLAP API is a Java application programming interface to OLAP Services. It is a querying language that selects and manipulates data in a data warehouse for display in a Java client. The analytical BI Beans are built using this API; you can extend (or even replace) the functionality provided by the BI Beans by using Java classes.

The Oracle OLAP DML

The Oracle OLAP DML is a data manipulation language that extends the analytic support of the OLAP API to include forecasting, modeling, and what-if scenarios. It operates on data that is stored (permanently or temporarily) in multidimensional objects in the analytic workspace.