Query Optimization - Duke Computer Science
This simple set of tools allows us to greatly improve the execution time of queries by optimizing RA plans!
Relational algebra, Codd's theorem - DATA Lab @ Northeastern? Use a cost model to estimate the cost of each plan. ? Select the ?cheapest? plan. ? We focus on cost-based optimizers. Magda Balazinska - CSE ... Query Optimization Algorithm Lessons Outline Relational Algebra ...a physical plan for a query is a relational algebra expression with choice of implementation for every operator the choices leave room for query ... Foundations of DatabasesGiven a relational algebra expression e, find another expression e0 equivalent to e that is easier (faster) to evaluate. ? Basic question: Given two relational ...
Autres Cours: