XML/A (XML for Analysis) is a de facto standard method to work with OLAP data sources using a (SOAP) webservice protocol. What this boils down to is that you can use ordinary HTTP client requests, such as those emitted by common internet browsers, to discover the structure of OLAP cubes, and to execute MDX queries. While HTTP is used as communication protocol, XML/A uses XML documents as the actual carrier of the information.
Being a de facto standard, XML/A is broadly implemented by OLAP servers from different vendors, such as Microsoft, SAP, SAS, and also Pentaho/Mondrian. Some vendors support XML/A simply as compatibility feature next to a proprietary binary communication protocol, while other vendors use XML/A as the principal gateway for OLAP clients.
Typically, XML/A is not directly visible to end users and application developers alike. End user tools like cube browsers will usually work with OLAP datasources through an API that shields the application from creating and interpreting the XML/A SOAP messages. One example of such a library is the org.olap4j.driver.xmla java package, which implements the olap4j to XML for Analysis bridge (see: http://www.olap4j.org/api/index.html).
- discovery (OLAP metadata) as well as execution (MDX queries)
- supports synchronous an asynchronous communication
Xmla4Js is available under the terms of the LGPL license. It is hosted as a google code project at http://code.google.com/p/xmla4js/
In the presentation, I will show the basics of connecting to mondrian using Xmla4Js, discovering data sources, issuing MDX queries, and consuming results. Using a simple application, I will show how you can use Xmla4Js in your own web applications to deliver rich, provider independent OLAP.
Xmla4js.pdf - PDF format
The recording is now available on the WebEx service site. Click the link below to download or play it:
Pentaho Community Techncal WebEx - OLAP and Analysis for web applications using XMLA-20100113 1502
Wednesday, January 13, 2010 10:02 am New York (Eastern Time, GMT-05:00)
1 Hour 6 Minutes
Project with source code, doc and samples http://code.google.com/p/xmla4js/