An algorithm for maintenance of functional relationships

The computational complexity of the problem of the determination of keys and functional dependencies for a relational schema is, in the worst case, exponential with respect to the number of attributes involved in the description of an application. The algorithm presented computes the set of functional dependencies from a static sample set of objects. However, usually in real-life applications, the data availability for such an analysis is subject to some dynamic changes. A facility to support such behaviour is built into the presented algorithm. This is based on the strategy of the maintenance of the set of FDs-providing their necessary modifications, which are triggered by an expansion of the set of objects. The algorithm is demonstrated in a nontrivial example. The significance of the offered solution is twofold; avoidance of the repetition of the whole (standard) procedure for the dynamically changing data, and an improvement in the execution time in comparison to the standard methods. The results presented are of an importance for any automation efforts in information analysis such as a construction of a CASE tool