Pentaho is releasing olap4j 1.0, which provides an open source API for Java developers to access multiple OLAP (Online Analytical Processing) servers in business intelligence applications.

With the API, developers gain a single API for accessing the Mondrian OLAP server and Pentaho BI Server. Other servers supported include Microsoft SQL Server Analysis Services 2005 and 2008, SAP BW and Jedox Palo. Oracle's Essbase server may be supported at some point as well.

Pentaho likens olap4j to the  JDBC (Java Database Connectivity) API, except it is for business intelligence. "The API is designed to be as much like JDBC as possible," said Julian Hyde, chief architect at Pentaho and founder of Mondrian and olap4j. Java developers experienced with database programming will find the API familiar, according to Pentaho.

In development since 2006, olap4j 1.0 enables developers to use a standard API instead of having to use each OLAP vendor's API. Without this API, a developer building a sales analysis visualisation component, for example, would have to individually choose an OLAP server to access at the back end. Olap4j works with Mondrian and XMLA (XML for Analysis) drivers, which communicate with analytic databases. Other participants in developing olap4j 1.0 include SQL Power Group, Jedox, Matrix CPM Solutions, Saiku and Aschauer.

A user of olap4j found that it worked as a way to connect to different data sources. "Olap4j looked like the best way we could find to provide access to the largest number of multidimensional data sources," said Jonathan Fuerth. He said he had used the technology when working at business intelligence and data migration software company SQL Power. The API, however, proved "a bit awkward" in its extension of JDBC, Fuerth said. Olap4j extended JDBC to multidimensional databases, he said.