In SQL Server 2012, there is a new data model called Tabular which is an addition to the existing Multidimensional Model.
So what are the limits for Tabular data model?
Feature | Multidimensional | Tabular |
Calculated measures | Yes | Yes |
Distinct count | Yes | Yes (via DAX) |
Hierarchies | Yes | Yes |
KPIs | Yes | Yes (not trends) |
Actions | Yes | No |
Linked objects | Yes | No |
Many-to-many relationships | Yes | No |
Parent-child hierarchies | Yes | Yes (via DAX) |
Partitions | Yes | Yes |
Perspectives | Yes | Yes |
Semi-additive measures | Yes | Yes |
Translations | Yes | No |
User-defined hierarchies | Yes | Yes |
Custom assemblies | Yes | No |
Custom rollups | Yes | No |
Writeback | Yes | No |
Data mining | Yes | No |
If you require data mining, writeback, or translations within a data model, this can only be facilitated by multidimensional data models.