Evolutionary techniques for updating query cost models in a dynamic multidatabase environment

Developing Evolutionary Cost Models for Query Optimization in a Dynamic Multidatabase Environment

Deriving local cost models for query optimization in a multidatabase system (MDBS) is a challenging issue due to local autonomy. It becomes even more difficult when dynamic environmental factors are taken into consideration. In this paper, we study how to evolve a cost model to capture a slowly-changing dynamic MDBS environment so that the cost model is kept up-to-date all the time. We propose ...

Global Query Optimization Based on Multistate Cost Models for a Dynamic Multidatabase System

Global query optimization in a multidatabase system (MDBS) is a challenging issue since some local optimization information such as local cost models may not be available at the global level due to local autonomy. It becomes even more difficult when dynamic environmental factors are taken into consideration. In our previous work, a qualitative approach was suggested to build so-called multistat...

Developing Cost Models with Qualitative Variables for Dynamic Multidatabase Environments

A major challenge for global query optimization in a multidatabase system (MDBS) is lack of local cost information at the global level due to local autonomy. A number of methods to derive local cost models have been suggested recently. However, these methods are only suitable for a static multidatabase environment. In this paper, we propose a new multi-states query sampling method to develop lo...

A New Framework For Query Optimization In Multidatabase System Environment

Due to the changing business environment, the need arises to integrate the pre-existing database system in federated way. A great effort had been done to enhance the performance of the Multidatabase management system (MDBMS). The most critical issue considered in this area is the query optimization that can be considered as the backbone of any successful database. Reviewing the most recent rela...

Dynamic Query Optimization and Query Processing in Multidatabase Systems