Techniques to dynamically select data sources for users and to direct queries for the users to the proper data sources. Initially, user information (e.g., user name) for each user is received and used to determine a data source designated for the user. The designated data source may be determined via a look-up table or by running a query with the user information to obtain the identity (e.g., the logical name) of the data source. A data source variable for each user can then be set to the identity of the designated data source. Thereafter, queries for each user are directed to the user's designated data source by determining database connection information for the designated data source based on the data source variable and using this information to direct the queries.