Web Services for DB2 Cube Views has been released by IBM alphaWorks labs as the latest example of emerging 'alpha code' technologies. Web Services for DB2 Cube Views provides "access to multidimensional data stored in DB2. These Web services allow a client application to read data from the cubes and perform basic online analysis on multidimensional data and metadata through the Web, using XPath and XML. OLAP applications working on top of relational data must generate multipass SQL statements and then do further processing on rows returned. Web Services for DB2 Cube Views is an all-XML solution for querying OLAP metadata and data. It uses IBM DB2 Cube Views to retrieve OLAP metadata. Web Services for DB2 Cube Views can also be viewed as an extension to other XML-based database query processors, such as XML for Tables. While basic XML engines map plain relational tables into XML documents, Web Services for DB2 Cube Views add a multidimensional structure with aggregation hierarchies. The query language is still XML-based. Actually, XPath is reused as a query language for OLAP cubes. The client application, or, more specifically, the programmer of the application, is not required to understand a specialized OLAP query language. The similarity to other XML-based query systems is an important design goal."

Web Services for DB2 Cube Views: How It Works

Web Services for DB2 Cube Views is an XML SOAP application and can be accessed regardless of the platform or programming language you use. In order to interact with the Web Services for DB2 Cube Views provider, you will have to create a SOAP client using the the WSDL of the Web service. This WSDL is included in the package.

Since this operation requires strong knowledge of programming language and Web service architecture, the package also includes an "out-of-the-box" solution in the form of an HTML front end. We encourage you to use this front end to become familiar with the Web service. Please refer to the documentation for information on how to install and use this front end.

[In Web Services for DB2 Cube Views], "application queries are based on XPath. These are parsed by Web Services for DB2 Cube Views to generate SQL queries. Then the data is returned in XML format. The client application interacts with Web Services for DB2 Cube Views by the mean of three methods: Describe(): Allows a client to query OLAP metadata stored in DB2 Cube Views using XPath; Members(): Allows a client to query reference data (members) using XPath; Execute(): Allows a client to perform basic OLAP "slice-and-dice" queries using XPath.

Multidimensional Services: DB2 Cube Views provides a SQL-based and XML-based application programming interface (API) for OLAP tools and application developers. Through CLI, ODBC, or JDBC connections or by using embedded SQl to DB2, applications and tools can use a single stored procedure to create, modify, and retrieve metadata objects.

Definitions of OLAP cubes in DB2 can be maintained by the new product DB2 Cube Views. A short introduction of DB2 as a server for OLAP cubes is available in the DB2magazine article "The OLAP-Aware Database." [adapged from the FAQ and main website description]

System Requirements

Web Services for DB2 Cube Views requires a Java platform and computer with 512 MB of memory. Additionally: IBM DB2 8.1, Fixpack 2; IBM DB2 Cube Views -- includes sample database MDSAMPLE; IBM WebSphere Application Server 5.0 or Apache TOMCAT 4.1; Apache SOAP, but only if you are using Apache TOMCAT (not necessary with IBM WebSphere).