Thesis from 2008 in the field of Computer Science - Programming, grade: 1.0, University of Koblenz-Landau (Institute for Software Engineering), 10 sources in the bibliography, language: German. Abstract: This thesis designs and implements an optimizer for the TGraph query language GReQL2. GReQL2 essentially consists of three components: the parser, the evaluator, and the optimizer. The parser has already been implemented by Katrin Marchewka, and the evaluator is the result of Daniel Bildhauer's thesis. The optimizer developed in this work includes a component for logging evaluation metrics, a cost model that can estimate the evaluation costs of a query based on the logged empirical data, a mechanism for reusing already optimized syntax graphs, and a series of transformations.