Database Management System research in this period centers on real-time design that balances timing constraints with multilevel security, trading throughput for verifiable guarantees in real-time environments. Semantic modeling and schema transformation address heterogeneity and imperfect information to enable cross-database interoperability and conceptual clarity. Storage hierarchy and memory management explore hierarchical storage, tertiary memory, and main-memory approaches to optimize data access, while the field evolves toward autonomic computing and contract-based transactions, including migrations between relational and object-oriented models. Historical Significance: The introduction of the Skyline operator provided a practical framework for multi-criteria queries, catalyzing extensive research on preference queries and skyline computation. The emergence of moving objects databases formalized trajectory data management and indexing strategies, shaping early Location-Based Services. Data federation established federated approaches for integrating autonomous heterogeneous databases, and two-level serializability offered a compromise between correctness and local autonomy in distributed environments.