From reporting perspective, OBIEE allows you to create a report from two Subject Areas.
But since the source data is in OLAP, a better approach will be to "join" the cubes together in AWM using Calculated Measures.
Lets say CUBE1 has dimensionality DIM1, DIM2, DIM3, DIM4
and CUBE2 has dimensionality DIM1, DIM2, DIM5, DIM6
Create a new cube (lets call it RPT_CUBE) with dimensionality DIM1, DIM2, DIM3, DIM4, DIM5, DIM6
This cube will not have any STORED measures.
It will only have calculated measures which are required for reporting.
In OBIEE, you should then import (and use) only RPT_CUBE. No need to expose and use CUBE1 and CUBE2 in OBIEE.
This is one of the best-practices for OBIEE - OLAP reporting.
Thank you, but what happens to the other reports which were using the old RPD once I upload the new one with the new reports. I guess my worry is that once I upload the new RPD I will have a broken link to the old reports?
Let me know how this is resolved
Newer rpd should be a superset of the older rpd i.e. keep old cubes CUBE1 and CUBE2 in your rpd in addition to modeling new cube RPT_CUBE in the rpd.
If older reports were using the cubes directly (all measures in report came from a single cube) then they would have worked earlier and will continue to work with new rpd.
Use new cube RPT_CUBE for all future report development work. You can modify and phase out the older reports and access RPT_CUBE alone at your convenience.