Data Dependence Analysis for an Untrusted Transaction Manager

There are two components in the scheduler for multilevel-secure databases which use the replicated architecture; global and local schedulers. Since the global scheduler, which enforces data consistency among replicas, has to make scheduling decisions based on transactions (i.e., without any knowledge of actual data or physical layout of data), an accurate analysis technique which can detect conflicts among queries is needed. The data dependence analysis introduced here provides a method for precisely determining whether the portions of relations affected by various database operations overlap without the knowledge of actual data.