The Intelligence Enterprise's weblog has a new article about Oracle 11g. One thing worth highlighted is the feature he feel impressed about on the advancement of OLAP.
"Materialized views are a technique for speeding multidimensional queries, such as those exploring sales across regions, products and customers. However, as the number of materialized views mounts along with query volumes and complexity, managing those views becomes difficult. In 11g, Oracle is using an OLAP cube to store up to millions of materialized views so they can be managed more efficiently."
One of the problems of the old materialized view is that you have to know the level you are going to reported by and create the materialized view accordingly. The benefit of using an OLAP engine is that the aggregation can be available at many different levels andyou do not need to created multiple specific materialized views for storing the summaries. However, the OLAP cubes was stored in a different technology and populated in different languages. You need to write codes to map the data from your source system or warehouse to the cubes. The process needs to be run periodically in order to have the refreshed data from OLAP. Also, querying the data from OLAP requires a different programming interface, unless you create the OLAP-to-Relational mapping view.
The new feature of 11g seems combining the best from both world and solve all the problems!
