Abstract. Bottom-up evaluation is a central part of query evaluation / program execution in deductive databases. It is used after a source code optimization like magic sets or SLDmagic that ensures that only facts relevant for the query can be derived. Then bottomup evaluation simply performs the iteration of the standard TP -operator to compute the minimal model. However, there are different ways to implement bottom-up evaluation efficiently. Since this is most critical for the performance of a deductive database system, and since performance is critical for the acceptance of deductive database technology, this question deserves a thorough analysis. In this paper we start this work by discussing several different implementation alternatives. Especially, we propose a new implementation of bottom-up evaluation called “Push-Method”.