On Query Optimization in Relational Databases

TL;DR: According to the experiments, several factors (the design of database, the difference between DBMSs, the selection of indexes) could be the reasons of the system performance and should be considered when implementing the optimization.

TL;DR: A multi query shareability algorithm which can efficiently detect the common sub-expressions among the multiple queries and share the output among the queries was proposed and algorithm for optimal order of those queries was also proposed.

TL;DR: This paper will introduce the reader to the most basic concepts of server performance tuning, query processing and optimization of queryprocessing and hope this paper will provide an adequate support to Database Administrator(s) (DBAs) who are working on Sybase and researchers who is working on Database Server performance tuning and query optimization.

TL;DR: This work presents efficient techniques that are able to guarantee the choice of an optimal plan over the desired execution space for both the naive algorithm as well as for the optimization algorithm with complete rank-ordering, without compromising optimality.

TL;DR: Experiments show that all three of f, DFBB, and dynamic query ordering help to improve the perfor-mance of the authors' h4Q0 algorithm, and compared hexisting methods which use A* and static query order-ing.

TL;DR: A new heuristic function (hc), dynamic query ordering heuristics, and Depth-First Branch-and-Bound (DFBB) are defined and experimentally evaluated, and compared with existing methods which use A* and static query ordering.

TL;DR: This chapter discusses database models, access methods, and performance in the context of a relational database.