A large retail company keeps sales data local to the individual branches where sales transactions were performed. To compute overall sales statistics, the company wants to avoid sending the full sales data set to a central server. Instead, only aggregated sales information (sum, average, minimum, variance, median, maximum) is sent from each branch to the central site. Which of the following statements are correct? a) The overall sum can be derived from the sums per branch. b) The overall average can be derived from the averages per branch. c) The overall minimum can be derived from the minimums per branch.

A large retail company keeps sales data local to the individual branches where sales transactions were performed. To compute overall sales statistics, the company wants to avoid sending the full sales data set to a central server. Instead, only aggregated sales information (sum, average, minimum, variance, median, maximum) is sent from each branch to the central site. Which of the following statements are correct? a) The overall sum can be derived from the sums per branch. b) The overall average can be derived from the averages per branch. c) The overall minimum can be derived from the minimums per branch.

Database Systems: Design, Implementation, & Management

11th Edition

ISBN:9781285196145

Author:Steven, Steven Morris, Carlos Coronel, Carlos, Coronel, Carlos; Morris, Carlos Coronel and Steven Morris, Carlos Coronel; Steven Morris, Steven Morris; Carlos Coronel

Publisher:Steven, Steven Morris, Carlos Coronel, Carlos, Coronel, Carlos; Morris, Carlos Coronel and Steven Morris, Carlos Coronel; Steven Morris, Steven Morris; Carlos Coronel

Chapter11: Database Performance Tuning And Query Optimization

Section: Chapter Questions

Problem 20P

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