As mentioned earlier, Mondrian is the core engine of OLAP, responsible for calculating, cache data from the relational database, responding to queries from the MS home MDX syntax from the performance layer. Specific performance form is a JAR, start with Tomcat.
After reading the Sample of the Foodmart, he did it.
First first step is to design the database structure of OLAP.
Because of the business database, OLAP needs redundant data to reach faster queries. Before designing, please pay attention to the classic "Full Dimension Design Guide", and the Chinese version will be probably. In fact, it is to remove the columns unrelated to the report, combine the order, order detail into a sales fact table, combined the product, product classification, two tables into a product dimension. Action. After the design, there should be a few factops with statistics and dimensional foreign keys, and several dimensions for classification, sorting, and filtering.
The second step is to guide the data in the business database.
There are a lot of ETL tools that make a large number of maps of mapping and transform class. But I still like to write SQL and shortcut directly, maybe I face it a day of a G's database.
The third step is to define the database structure that has just been designed into Schema.
The SCHEMA meta model includes dimensions, hierachies, levels, and members. Mondrian wants to aggregate data respond to the Query of the MDX syntax from the relational database.
Before this step, I remember to first install a Chinese version of SQL Server2000, and the HELP file inside has a detailed explanation. In addition, JProvit has a sub-project, which is this Schema's Eclipse Plug-in. Even without this plug-in, with its DTD, you can avoid spelling errors in other XML editors. Made blueml with Foodmart.xml in Sample, you can copy Paste from your own schema. Finally, note that Oracle's column name must be written.
Related Articles: Poor's General OLAP Solution I - General OLAP Solution I I - Mondrian Engine Poor III - JPivot Express Layer
