Fuzzy dependency and its applications in damage assessment and recovery

Fuzzy dependency in a database delineates a loose dependency relationship between two sets of attributes. It describes logical relationships among attributes in a database relation and those relationships can´t be fully specified by functional dependencies, which focus on database schema and data organization. This characteristic of the database schema can be used to perform damage assessment and also to build fuzzy recovery model. In this paper, we formally define the concept of fuzzy dependency and introduce several inference rules. Then we focus on recovery from information attacks. An architecture for fuzzy value generation during recovery, based on fuzzy dependency relationships, is also presented. Fuzzy dependency can accelerate the post attack recovery process because it can generate acceptable values for damaged data quicker compared to that in traditional recovery schemes. Although the generated fuzzy values may not offer the absolute accuracy, they are acceptable for many real-time applications, which require prompt response more than the data accuracy.