Abstract: A system and method for providing simultaneous or independent access to disparate data sources in a single login session. A user logs into a front-end application session using a custom responsibility. The user submits a query for accessing data from backend enterprise databases, which store current and archived data separately. The data query is channeled to an interoperable layer. The query is modified to a union query at the interoperable layer, to facilitate simultaneous access to current and archived data. This is done by constructing similar queries for accessing data from each of the multiple data sources. The queries are subsequently combined. Next, the union query is routed to the backend database servers which process the query and retrieve data from current as well as archive databases, in response to the query. The retrieved data is then integrated and presented to the user as an exhaustive search result.