Mondrian

Mondrian is an Open Source Business Analytics engine that enables organizations of any size to give business users access to their data for interactive analysis. Users can build powerful Business Intelligence solutions with Mondrian as users’ Online Analytical Processing (OLAP) engine, enabling multidimensional queries against users’ business data, using the powerful MDX query language. Analyzing huge quantities of data has never been that easy.

With Mondrian, an open source Online Analytical Processing server (OLAP) written in JAVA, the system responds to queries fast enough to allow an interactive exploration of the data - even if they have millions of records, occupying several gigabytes. It brings multidimensional analysis to the masses, allowing users to examine business data by drilling and cross-tabulating information. There are several ways to use Mondrian in user application. If users have a fixed set of queries which users would like to display as HTML tables, use the tab library.

The JPivot project is a JSP-based pivot table, and will allow users to dynamically explore a data set over the web. Mondrian can handle large data sets if users’ RDBMS can. Mondrian delegates the aggregation to the RDBMS, and if users RDBMS happens to have materialized group by views created, users’ query will fly. And the next time users run the same or a similar query that will really fly, because the results will be in the aggregation cache. Mondrian's main API is olap4j, an extension to JDBC for OLAP applications. It also has a XML provider for Analysis.