This paper, the first step to connect relational databases with systems consequence, is concerned with the semantics of relational databases. It aims to study system consequence in the logical/semantic system of relational databases. The paper, which was inspired by and which extends a recent set of papers on the theory of relational database systems, is linked with work on the Information Flow Framework connected with the ontology tandards effort (SUO), since relational databases naturally embed into first order logic. The database semantics discussed here is concerned with the conceptual level of database architecture. The authors offer both an intuitive and technical discussion.