Select Data Storage (Usage-Based Optimization Wizard)
In this step of the wizard, you specify the type of data storage you want to use to store the data and aggregations for your cube or partition. This step appears if you selected Replace the existing aggregations in the previous step of the wizard.
Options
MOLAP
Select to store the data for your cube or partition in a multidimensional structure. The aggregations you design for this storage type will also be stored with the multidimensional data.
Multidimensional OLAP (MOLAP) storage provides the potential for the most rapid query response times, depending only on the percentage and design of the cube's aggregations. In general, MOLAP is more appropriate for cubes that are used frequently and which require rapid query response.
ROLAP
Select to keep the data for your cube or partition in the existing relational data store. The aggregations you design for this storage type will also be stored in the relational database, rather than in a multidimensional structure.
Relational OLAP (ROLAP) query response is generally slower than that available with the other two options. A typical use of ROLAP is for large datasets that are infrequently queried, such as historical data from less recent years.
HOLAP
Select to keep the data for your cube or partition in the existing relational data store and your aggregations in a multidimensional structure.
For queries that access summary data, hybrid OLAP (HOLAP) is the equivalent of MOLAP. Queries that access base data, such as a drill-down to a single fact, must retrieve data from the relational database and will not be as fast as if the base data were stored in the MOLAP structure. Cubes stored as HOLAP are smaller than equivalent MOLAP cubes and respond faster than ROLAP cubes for queries involving summary data. HOLAP storage is generally suitable for cubes that require rapid query response for summaries based on a large amount of base data.