A Region Based Query Optimizer Through Cascades Query Optimizer Framework.
Fatma Özcan, Sena Nural, Pınar Köksal, Mehmet Altınel, Asuman Doğaç · 1995
The Cascades Query Optimizer Framework is a tool to help the database implementor (DBI) in constructing a query optimizer for a DBMS. It is data model independent and allows to code a query optimizer by providing the implementations of the subclasses of predefined interface classes. When the implementations of the required classes are provided properly, the generated optimizer produces the optimum execution plans for the queries. Although providing the complete set of rules and thus finding the optimum execution plans are beneficial for most of the queries, the query optimization time increases unacceptably for certain types of queries, e.g., for star queries. Hence it is important to be able to limit the number of alternative plans considered by the optimizer for specific types of queries by using the proper heuristics for each type. This leads to the concept of region based query optimization, where different types of queries are optimized by using different search strategies...