Enabling ROLAP drilling for reports accessing Intelligent Cubes

Reports that access an Intelligent Cube can be granted full ROLAP access to the data warehouse through drilling. This means that you can enable drilling outside of the Intelligent Cube to access the full set of data available in the data warehouse.

While this extends the analysis and data access capabilities of reports that access Intelligent Cubes, drilling outside of an Intelligent Cube can require additional load on the Intelligence Server and data warehouse. This is because drilling outside of an Intelligent Cube requires a new report to be executed against the data warehouse.

All reports that access Intelligent Cubes can drill within the data included in an Intelligent Cube. This provides ROLAP-type analysis without having to re-execute against the data warehouse. For example, an Intelligent Cube includes Year and Quarter. A report accessing the Intelligent Cube only includes Year on the report. On the report, you can drill down from Year to Quarter, which returns the results without any extra load on the data warehouse or Intelligence Server.

The decision to enable or disable drilling outside of an Intelligent Cube depends on a few factors. You should consider the size and complexity of your Intelligent Cubes when deciding whether to enable drilling outside of an Intelligent Cube. While enabling drilling outside of relatively small Intelligent Cubes can give the benefit of ROLAP analysis through drilling, enabling this analysis on relatively large Intelligent Cubes has the potential to cause increased load on your data warehouse and Intelligence Server.

By enabling drilling outside of an Intelligent Cube, reports that access the Intelligent Cube have ROLAP access to data through drilling. For example, an Intelligent Cube includes Year but not Quarter. A report accessing the Intelligent Cube includes Year and drilling outside of the Intelligent Cube is enabled. On the report, you drill down from Year to Quarter. This causes a new report to be created and executed against the data warehouse.

The benefit of enabling this extra analysis can come with a performance cost. As mentioned above, when you drill outside of an Intelligent Cube a new report is created and executed against the data warehouse. This action does not take advantage of the data stored in the Intelligent Cube.

When this drilled-to report is created, only objects that were on the report layout of the report you drilled from are included in the drilled-to report. Any objects that are only in the Report Objects pane of the report you drilled from are not included in the drilled-to report. This can help reduce the size of the drilled-to report. However, if you are drilling from a report that accesses a large Intelligent Cube, it is possible that a user could include all objects of an Intelligent Cube on a report. Drilling outside of the Intelligent Cube on such a report could cause excessive load on the data warehouse and Intelligence Server.

The procedures below describe the steps to enable drilling outside of a specific Intelligent Cube, or any Intelligent Cubes in a project: