ACM Transactions on Database Systems

A modularization discipline for database schemas is first described. The dicipline incorporates both a strategy for enforcing integrity constraints and a tactic for organizing large sets of database structures, integrity constraints, and operations. A ...

Not all queries in relational calculus can be answered sensibly when disjunction, negation, and universal quantification are allowed. The class of relation calculus queries or formulas that have sensible answers is called the domain independent class ...

Consider the class of distributed database systems consisting of a set of nodes connected by a high bandwidth network. Each node consists of a processor, a random access memory, and a slower but much larger memory such as a disk. There is no shared ...

We present a dynamic external hash method that allows retrieval of a record by only one access to mass storage while maintaining a high load factor. The hash function is based on generalized spiral storage. Both primary and overflow records are allocated ...

A remote backup database system tracks the state of a primary system, taking over transaction processing when disaster hits the primary site. The primary and backup sites are physically isolated so that failures at one site are unlikely to propogate to ...