As with any exam, it will vary from person to person as to what is deemed to be difficult. Be sure you are familiar with each of the topics in the exam objectives listed below.
OLAP databases are designed to speed up the retrieval of data. They contain two basic types of data: measures and dimensions. Measures are numeric data[md]the quantities, and averages that you use to make informed business decisions. Dimensions are the categories that you use to organize these measures. OLAP databases help you to organize data by many levels of detail, using the same categories that you are familiar with to analyze the data.
A Cube is a data structure that aggregates the measures by the levels and hierarchies of each of the dimensions to be analyzed. Cubes combine several dimensions, such as time, product lines, and geography with summarized data.
Adding role members in the development environment can overwrite changes made in production to the list of role members when you deploy. The easiest way to test dynamic security is to add role members. These role members should be removed before you deploy the model.
OLAP data can be stored in MOLAP and ROLAP data architectures on disk. In MOLAP architecture, data is stored on disk in an optimized multidimensional format with typical 3x compression. In ROLAP, data is stored in the source relational database.