Index structures in object-oriented database management systems should support selections not only with respect to physical object attributes, but also with respect to derived attributes. A simple example arises, if we assume the object types Company, Division, and Employee, with the relationships has-division born Company to Division, and employsfrom Division to Employee. In this case the index structureshould allow to support queries for companies specifying thenumber of employees of the company. Unfortunately, there is one main problem with indexstructures addressing derived attributes, namely the question: Which entries in which index structures have to beupdated after a certain update in the object base? In the example above, the creation of a new employee must trigger an index update for the corresponding company. In the present paper we propose a practical solution for this problem. This solution is based on so-called index update definitions which comprise (1) an event description for the event causing the need for the index update, (2) a reference for the affected index structure, (3) a query determining the elements for which the respective index entries have to be updated, and (4) the corresponding tipdnte operation. Using these index update definitions we can handle complex derived attributes defined e.g. employing regular path expressions. The paper first describes the environment for our considerations originating from the fields of software engineering environments and information retrieval. Thereafter the use of our approach is demonstrated by the help of a comprehensive example. Finally we sketch the implementation of our approach based on a multi-thread architecture