The ROLAP report can be useful for the following reasons:

• ROLAP report provides access to databases other than Analysis Services: Sql Server, Access, MySql, Oracle, and DB2.
• ROLAP report lets you design cubes online.
• ROLAP report can be useful for Data-Warehouse to Analysis Services data validation.
• Sometimes, for various reason, not all Data-Warehouse data gets into the Analysis Services. ROLAP report provides a way to see the missing data.
• ROLAP report can consume aggregation data that resides in the source system.
• Sometimes, SQL provides a faster alternative to Analysis Services when it comes to viewing detailed data.
• ROLAP report lets you specify filter types like Date Picker, Textbox or Textbox.
• For those who don’t understand MDX, SQL is easier to understand and manage.