MOLAP vs ROLAP (DOLAP)

The obvious differences between MOLAP and ROLAP are probably around performance (MOLAP is faster), maintenance (ROLAP is easier) and perhaps size (cubes may not scale well beyond some GB). However, there are some fundamental differences in functionality which we seem to miss out when deciding one way or the other. MOLAP inherently supports a lot of time-series analysis which can only be achieved using extensive analytic functions (if the DBMS supports it, that is) in ROLAP. So, if you have a smallish DW (less than 100 GB, say) and do extensive time-series analysis (e.g., YTD sales comparison), weighted averages, etc., read this and you may decide on MOLAP (or MOLAP + ROLAP)!