In this paper we study the expressive power of the logical data model LDM Introduced in [KV84]. We show that even thong the logical data model is semantically powerful, it is not overly powerful so as to be intractable we demonstrate it from three aspects first we study the complexity of checking integrity constraints, and we show that is no more difficult than checking integrity constrains in the relational model secondly we show that the logic of the model is essentially fist-order that means for example that one can use a standard theorem-prover cither in the database design process on for deductive query answering.