General OLAP Solutions

Cloveretl

Cloveretl is a data ETL framework that extracts business data and converts it to the type required by OLAP. It is still stored in relational databases. Typically, the order and orderitem tables in the parent-child relationship need to be converted into a fact table. In orderitem, a large amount of redundant order data, such as date, customer, and branch, is required for statistics convenience. It seems that this is only a few lines in the cloveretl framework.Code, Three table structure definitions.

Mondrian

Mondrian, the core OLAP engine, is responsible for computing and caching data from relational databases and responding to queries from the presentation layer using the ms mdx syntax. The MDX Syntax of Microsoft is not difficult to learn. All SQL Server books are taught.
At this layer, You need to define a schema meta-model, including dimensions, hierarchies, levels, and members. Mondrian uses it to aggregate data from relational databases to respond to queries in the MDX syntax.

July

Olap jsp m tag library. Provides OLAP navigator and multi-dimensional data display, and supports chart generation and export to excel. Mondrian's premium presentation layer.