Provenance in Dynamic Data Systems

Most digital data sets are subject to modifications. For example, scientific data may be updated according to the new experimental results, and sales data updated periodically according to new sales made. We often have data derived from these digital data sets. Our concern in this paper is the provenance of such derived data. Can we explain what a particular derived datum depends on, even if a value used in its derivation has since been modified. Can we determine if a particular derived value is still valid without performing full view maintenance. Questions of this sort are likely to arise when we derive results from modifiable data. We present in this paper an overview of problems that arise in this context, with regard to fine-grain data provenance, and outline solutions to some of these problems.