Kód: 16367521
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 o ... celý popis
Angličtina
32.10 €
Bežne: 37.70 €
Ušetríte 5.60 €

Nákupom získate 78 bodov
Anotácia knihy
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.
Parametre knihy
32.10 €
Angličtina
Osobný odber Bratislava a 12762 dalších
Copyright ©2008-26 najlacnejsie-knihy.sk Všetky práva vyhradenéSúkromieCookies
24 miliónov titulov
Vrátenie do mesiaca
02/210 210 99 (8-15.30h)Nákupný košík ( prázdny )