ComputerScienceExpert

(11)

$18/per page/

About ComputerScienceExpert

Levels Tought:
Elementary,Middle School,High School,College,University,PHD

Expertise:
Applied Sciences,Calculus See all
Applied Sciences,Calculus,Chemistry,Computer Science,Environmental science,Information Systems,Science Hide all
Teaching Since: Apr 2017
Last Sign in: 9 Weeks Ago, 3 Days Ago
Questions Answered: 4870
Tutorials Posted: 4863

Education

  • MBA IT, Mater in Science and Technology
    Devry
    Jul-1996 - Jul-2000

Experience

  • Professor
    Devry University
    Mar-2010 - Oct-2016

Category > Programming Posted 28 Apr 2017 My Price 9.00

compute the projection πspeed

  • For the following PC relation, suppose we compute the projection Ï€speed (PC). What is the value of this expression as a set? As a bag? What is the average value of tuples in this projection, when treated as a set? As a bag? (20 points)
  • model
  • speed
  • ram
  • hd
  • price
  • 1001
  • 2.66
  • 1024
  • 250
  • 2114
  • 1002
  • 2.10
  • 512
  • 250
  • 995
  • 1003
  • 1.42
  • 512
  • 80
  • 478
  • 1004
  • 2.80
  • 1024
  • 250
  • 649
  • 1005
  • 3.20
  • 512
  • 250
  • 630
  • 1006
  • 3.20
  • 1024
  • 320
  • 1049
  • 1007
  • 2.20
  • 1024
  • 200
  • 510
  • 1008
  • 2.20
  • 2048
  • 250
  • 770
  • 1009
  • 2.00
  • 1024
  • 250
  • 650
  • 1010
  • 2.80
  • 2048
  • 300
  • 770
  • 1011
  • 1.86
  • 2048
  • 160
  • 959
  • 1012
  • 2.80
  • 1024
  • 160
  • 649
  • 1013
  • 3.06
  • 512
  • 80
  • 529
  • For two relations:
  • R (A, B) = {(0,1), (2,3), (0,1), (2,4), (3,4)}
  • S(B, C) = {(0,1), (2,4), (2,5), (3,4), (0,2), (3,4)}
  • Compute the following: (40 points)
  • Ï€B+1,C-1 (S);      b) Ï„B,C (S);     c) δ(R);    d) γA,SUM(B) (R);    e) R OUTERJOIN R.B < S.B S   
  • List the isolation levels of transactions and explain their differences in your own words (10 points).
  • From the following base tables: (20 points)
  • MovieStar (name, address, gender, birthdate)
  • MovieExec (name, address, cert#, netWorth)
  • Studio (name, address, presC#)

Construct the following views:

  • A view  RichExec giving the name, address, certificate number and net worth of all executive with a net worth of at least $10,000,000.
  • A view StudioPres giving the name, address, and certificate number of all executive who are studio presidents.
  • For the same base tables in Question 5, declare indexes on the following attributes or combination of attributes (10 points).
  • address of MovieExec
  • gender and birthdate

Answers

(11)
Status NEW Posted 28 Apr 2017 02:04 AM My Price 9.00

-----------

Not Rated(0)