The focus of this thesis is a proprietary database interface for management tables in memory. At the beginning, there is given a short introduction to the databases. Then the concept of in-memory database systems is presented. Also the main advantages and disadvantages of this solution are discussed. The theoretical introduction is ended by brief overview of existing systems. After that the basic information about energetic management system RIS are presented together with system's in-memory database interface. Further the work aims at the specification and design of required modifications and extensions of the interface. Then the implementation details and tests results are presented. In conclusion the results are summarized and future development is discussed.