In Oracle Fusion applications, there are two types of subject areas:
Subject areas whose names usually end with Real Time and access real-time (transactional) data
Subject areas whose names usually do not end with Real Time and access data warehouse data.
Many Fusion applications, especially dashboards, contain pre-built reports which do not access real-time data. Instead, they access data warehouse data. If you have not completed the post-provisioning steps to setup and configure a data warehouse, attempting to run a pre-built report in these Fusion applications will result in ODBC driver errors. For example, many dashboards pull data from the data warehouse and attempting to run a report from these dashboards, if the data warehouse has not been set up and configured, will generate errors.
You should run a report using a Real Time Subject Area only if a data warehouse has not been setup and configured for that subject area.