ABSTRACT
Part VI described security for distributed and heterogeneous database systems. In Chapter 15 we discussed discretionary security for distributed database systems. Essentially, we examined the security mechanisms discussed in Chapters 5 and 6 and extended them to a distributed environment. In Chapter 13 we discussed multilevel security for distributed database systems. Much of the discussion in this chapter is based on our own research on this topic in the 1990s. In Chapter 17 we discussed security for heterogeneous and federated database systems. We discussed architectures as well as challenges on integrating multiple security policies. We also discussed the inference problem both for distributed and heterogeneous database systems.
