BI Connector users may face data mismatch issues in the calculated columns created in Power BI, when connected to an OBIEE data source in Direct Query mode. 


The solution to solve this issue is simple. However, before jumping to the solution, it is important to understand why this mismatch occurs. For this purpose, let's first take a brief look at how BI Connector works.


Whenever a visual is created in Power BI, a query is generated in the back-end to fetch the required data from the data source (which is OBIEE in this case). BI Connector, in turn, transforms this query into OBIEE query language, and fetches the required data. This data is then provided back to Power BI to show up in the visuals.


Now that we have seen how BI Connector works, let's see why the data mismatch occurs. When a calculated column is created in Power BI, it is non-existent in the OBIEE data source, and BI Connector ends up attempting to fetch data from a non-existent column in the data source. Hence, the data mismatch occurs.


The solution to eliminate this mismatch is to create the calculated columns in the data source (OBIEE's Business layer), instead of creating it in Power BI. This Oracle article contains the steps to create a derived column in OBIEE.  


When derived columns are created in OBIEE environment (instead of creating them in the Power BI environment), the data mismatch issue arising in the Direct Query mode will be eliminated.