To the end users, the interface is the system. A better interface not only facilitates end user interaction with the database, it also enables them to formulate queries more efficiently and effectively. Two of the most important user-database interfaces are the conceptual and logical interfaces. With the conceptual interface, the user communicates with the database system in terms of entities, objects and relationships. On the other hand, the current user-database interaction is mainly based on the logical interface where the user expresses the queries in terms of relations and join operations. Because the concepts at the logical interface are abstract and convoluted to ordinary users, many researchers argue that end users will be better off with the conceptual interface. This research will test this claim by comparing the effects of coneeptual and logical interfaces on the visual query performance of end users. The experimental study involves three tests: an initial test, a retention test and a relearning test. This allows us to assess the learning effect over time. The results show that users of the conceptual interface achieve higher accuracy, are more confident in their answers, and spend less time on the queries than users of the logical interface in all three tests.