Global Optimization and Parallelization of Integrity Constraint Checks.
Uwe Herzog, Jörg Schlösser · 1995
In this paper we consider the problem of efficiently checking integrity constraints. We concentrate on a combination of two optimization techniques: global optimization and parallelization. The primary objective of global optimization is to produce a global execution plan for a group of constraints where common subexpressions can be shared. Since parallelism is a promising strategy for improving efficiency in database systems we apply parallelism to integrity constraint checking. In a first step we compile the declarative constraints into appropriate constraint checks using an extended relational algebra. Then, the algebraic expressions are forwarded to our optimizer. Because many constraints have to be checked at the same time, considerable savings are possible in a second step by identifying common subexpressions in order to evaluate them only once. In a third step we generate parallel constraint execution plans, that are to be executed by a parallel constraint engine whi...