Abstract. The majority of database benchmarks currently in use in the

industry were designed for relational databases. A different class of

benchmarks became required for object oriented databases once they

appeared on the market. None of the currently existing benchmarks were designed to adequately exploit the distinctive features native to the

semantic databases. A new semantic benchmark is proposed which allows evaluation of the performance of the features characteristic of semantic database applications. An application used in the benchmark represents a class of problems requiring databases with sparse data, complex inheritances and many-to-many relations. Such databases can be naturally accommodated by semantic databases. A predefined implementation is not enforced allowing a designer to choose the most efficient structures available in the DBMS tested. The second part of this paper compares the performance of Sem-ODB binary semantic database vs. one of the leading relational databases. The results of the benchmark are analyzed.