А. С. Лопатенко Technical Report, 2004. , 12.2004  Аннотация In this paper we investigate different optimization techniques for query processing in networks of autonomous data sources, interconnected by means of GLAV mapping rules at the schema level. There are no restrictions on the topology of the network, in particular, cyclic networks are allowed. We have shown that knowledge of network structure may help to significantly improve the efficiency of query processing, both in the number of exchanged messages and in the time to get a complete answer. However, our optimization methods do not require advance knowledge of this topology, since the topology is discovered during query processing. The contributions of this paper include a definition of soundness and completeness for query processing in dynamic networks. Moreover, the query answering algorithm is shown to be efficient with respect to changes of the network. In particular, when the size of the change during query processing is sensibly less than the size of the network itself, query processing time is comparable to that of query processing in a stable network. The assumption that a change is small with respect to the size of whole network is reasonable for large scale networks. The results of experimental evaluation of the algorithm are presented.