Heterogeneous distributed database management: The HD-DBMS

The proliferation of different DBMS and advances in computer networking and communications have led to increasing heterogeneous distributed DBMS network scenarios. Major heterogeneity problems and challenges include: different database models, syntactically and semantically different DBMS, different types of controls (recovery, etc.), etc. We address herein the long-range goal for a heterogeneous distributed DBMS (HD-DBMS) to be able to support a network in which any user in any node can be given an integrated and tailored view or schema, while in reality the data may reside in one single database or in physically separated databases, managed individually by the same type of DBMS (by the only one the user understands) or by different DBMS. We cite the major approaches to data sharing and accessing: from the primitive commercial file and database unload/load and PC download, to common interfaces on top of existing DBMS, to the R&D and prototype efforts toward the long-range desires. Commercial availability of the more encompassing thrusts may become a reality with the mounting problems, opportunity costs, and demand for data sharing in the heterogeneous world. Major research and development projects in this arena are leading toward some partial attainment of the long-range objective. The UCLA HD-DBMS project is highlighted herein, with a presentation of its status, progress, and plans. It is a longer range project, with the unique feature of allowing any user in the network to use a preferred database model and DML to access or update any data in the heterogeneous network. HD-DBM5 is to provide a multilingual interface to heterogeneous distributed databases.