On the linkage of dynamic tables in relational DBMSs

Abstract

Tables and operations over tables are at the center of the relational model and have been at the core of the Structured Query Language (SQL) since its development in the 1970s. As database applications have grown rapidly, the conceptof tables has been generalized in database languages. The new generalized table conceptin the SQL standard and in some commercial databases includes explicitly defined derived tables, such as user-defined temporary tables, transition tables, user-defined table functions, and table locators, that can be manipulated by users. We call them dynamic tables, because their entities exist only at run time. The challenges that these dynamic tables pose to existing relational engines lie in the linkage between the creation of the derived table and its references. In this paper, we describe a uniform framework for compile-time and run-time processing of dynamic tables. We also give a thorough explanation of how such a generic framework can be realized in existing relational database management systems, such as IBM DATABASE 2™ Common Server. Our experience with our prototype has shown the simplicity, generality, and efficiency of our approach.