Engineering
Engineering, 11.12.2019 05:31, drdeb7766

Exercise 19.10 suppose you are given a relation r(a, b, c, d). for each of the following sets of fds, assuming they are the only dependencies that hold for r, do the following: (a) identify the candidate key(s) for r. (b) state whether or not the proposed decomposition of r into smaller relations is a good decomposition and briefly explain why or why not. 1. b --+ c, d --+ a; decornpose into bc and ad. 2. ab -+ c, c -~~ a, c d; decompose into a cd and be. ~~. a bc, c -+ ad; decornpose into abc and ad. 4. a b, b c, c '-1 d; decornpose into ab and a cd. 5. a --+ b, b -+ c, c d; decoinpose into ab, ad and cd.

answer
Answers: 2

Other questions on the subject: Engineering

image
Engineering, 04.07.2019 18:10, hadellolo8839
Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false
Answers: 3
image
Engineering, 04.07.2019 18:10, jojoangelique13
The flow rate of air through a through a pipe is 0.02 m5/s. a pitot static tube is placed in the flow. the radius of the pitot static tube is 1 mm. assuming the flow to be steady and the air to be at 300k, calculate the difference in total and static pressure if the diameter of the pipe is: (a) d 0.1 m d 0.05 m (c) d 0.01 m
Answers: 2
image
Engineering, 04.07.2019 18:10, mamasbug4285
An air compression refrigeration system is to have an air pressure of 100 psia in the brine tank and an allowable air temperature increase of 60°f for standard vapor compression cycle temperatures of 77 f entering the expansion cylinder and 14 f entering the compression cylinder, calculate the coefficient of performance a. 2.5 b 3.3 c. 4.0 d. 5.0
Answers: 3
image
Engineering, 04.07.2019 18:20, hayleymckee
Steam enters a converging nozzle at 3.0 mpa and 500°c with a at 1.8 mpa. for a nozzle exit area of 32 cm2, determine the exit velocity, mass flow rate, and exit mach number if the nozzle: negligible velocity, and it exits (a) is isentropic (b) has an efficiency of 94 percent
Answers: 2
Do you know the correct answer?
Exercise 19.10 suppose you are given a relation r(a, b, c, d). for each of the following sets of fds...

Questions in other subjects: