Performance Evaluation and Optimization of Queries in Multi Databases

Sambit Kumar Mishra

ISBN 10: 3330079266 / ISBN 13: 9783330079267

Edité par LAP LAMBERT Academic Publishing, 2017

A propos de cet article

nach der Bestellung gedruckt Neuware - Printed after ordering - Modern database systems use a query optimizer to identify query plan to execute declarative SQL queries. Optimization is a mandatory exercise since the difference between the cost of the best plan and a random choice could be in orders of magnitude. The role of query optimizers is especially critical for the decision-support queries featured in data warehousing and data mining applications. For a query on a given database and system configuration, the optimizer's plan choice is primarily a function of the selectivities of the base relations participating in the query. In this chapter, it has been projected towards the cost of sub-query operations on the various sites, as well as the benefits achieved in the range of thirty to forty percent for various sub-operations like selection, projection and join. N° de réf. du vendeur 9783330079267

Détails bibliographiques

Titre : Performance Evaluation and Optimization of ...

Éditeur : LAP LAMBERT Academic Publishing

Date d'édition : 2017

Reliure : Taschenbuch

Etat : Neu

A propos de ce titre

Synopsis :

Modern database systems use a query optimizer to identify query plan to execute declarative SQL queries. Optimization is a mandatory exercise since the difference between the cost of the best plan and a random choice could be in orders of magnitude. The role of query optimizers is especially critical for the decision-support queries featured in data warehousing and data mining applications. For a query on a given database and system configuration, the optimizer’s plan choice is primarily a function of the selectivities of the base relations participating in the query. In this chapter, it has been projected towards the cost of sub-query operations on the various sites, as well as the benefits achieved in the range of thirty to forty percent for various sub-operations like selection, projection and join.