1) Why should NULLS in a relation be avoided as much as possible? Discuss the problem...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
1) Why should NULLS in a relation be avoided as much as possible? Discuss the problem of spurious tuples and how we may prevent it. 2) Define 1st, 2nd, and 3rd normal forms when only primary keys are considered. 3) What undesirable dependencies are avoided when a relation is in 2NF? 4) What undesirable dependencies are avoided when a relation is in 3NF? 5) List all functional dependencies of the following relation: A B C TUPLE# 10 bl cl 1 10 b2 c2 2 11 b4 cl 3 12 b3 c4 4 13 bl cl 5 14 b3 c4 6 6) Consider the following relation: CAR SALE(Car#, Date_sold, Salesperson#, Commission%, Discount_amt) Assume that a car may be sold by multiple salespeople, and hence {Car#, Salesperson#} is the primary key. Additional dependencies are Date_sold Discount_amt and Salesperson# Commission% Based on the given primary key, is this relation in INF, 2NF, or 3NF? Why or why not? How would you successively normalize it completely? 1) Why should NULLS in a relation be avoided as much as possible? Discuss the problem of spurious tuples and how we may prevent it. 2) Define 1st, 2nd, and 3rd normal forms when only primary keys are considered. 3) What undesirable dependencies are avoided when a relation is in 2NF? 4) What undesirable dependencies are avoided when a relation is in 3NF? 5) List all functional dependencies of the following relation: A B C TUPLE# 10 bl cl 1 10 b2 c2 2 11 b4 cl 3 12 b3 c4 4 13 bl cl 5 14 b3 c4 6 6) Consider the following relation: CAR SALE(Car#, Date_sold, Salesperson#, Commission%, Discount_amt) Assume that a car may be sold by multiple salespeople, and hence {Car#, Salesperson#} is the primary key. Additional dependencies are Date_sold Discount_amt and Salesperson# Commission% Based on the given primary key, is this relation in INF, 2NF, or 3NF? Why or why not? How would you successively normalize it completely?
Expert Answer:
Related Book For
Fundamentals Of Database Systems
ISBN: 9780133970777
7th Edition
Authors: Ramez Elmasri, Shamkant Navathe
Posted Date:
Students also viewed these databases questions
-
Why should NULLs in a relation be avoided as much as possible? Discuss the problem of spurious tuples and how we may prevent it.
-
Question: Check you are in charge of the design of both hardware and software for a new (but fairly conventional) workstation which will have its peripherals (for example a disc drive and a printer)...
-
In Exercises 35 through 42, the slope f'(x) at each point (x, y) on a curve y = f(x) is given along with a particular point (a, b) on the curve. Use this information to find f(x). f'(x) = 3x 2 + 6x ...
-
Exercise 10.7 described an experiment in which 26 resistivity observations were made on each of six different concrete mixtures. The article cited there gave the following sample means: 14.18, 17.94,...
-
In this exercise, we numerically verify that the probabilities derived for European calls also work for other contracts by (i) valuing the contracts starting from the value of a call, and (ii) by...
-
What are the prospects for the future of humanity?
-
Roger R. and Michelle N. Stewart (ages 45 and 46) are married and live at 641 Cody Way, Casper, WY 82609. Roger is a consulting engineer, and Michelle is a paralegal. They file a joint return and use...
-
Victory Company uses weighted average process costing. The company has two production processes. Conversion cost is added evenly throughout each process. Direct materials are added at the beginning...
-
Pecos Company acquired 100 percent of Suaro's outstanding stock for $1,450,000 cash on 1/1/2014, when Suaro had the following balance sheet: Cash - $37,000 Liabilities - ($422,000) Receivables -...
-
Prove that the triple 42, +, is a commutative ring, but not an integral domain. . Prove or disprove: the commutative ring Zp, O, O> has no zero divisors for each prime PEP.
-
A distillation column is used to separate a mixture of methanol, ethanol, and isopropyl alcohol. The feed stream, with a mass flow rate of 300 kg/hr, has the following composition: Component Species...
-
Trey Monson starts a merchandising business on December 1 and enters into the following three inventory purchases. Monson uses a perpetual inventory system. Also, on December 15, Monson sells 15...
-
Four of the wavelengths of the Balmer series occur in the visible spectrum (656 nm, 486 nm, 434 nm, and 410 nm). In which region of the electromagnetic spectrum does the fifth line, with a wavelength...
-
5. You have a radio that you know uses an RLC-circuit. It is tuned to f = 101.9 MHz. You are using a 2.4 10-7 H solenoid in your circuit and a 12 2 resistor. What is the capacitance that should be...
-
ammonia gas can be prepared by the reaction of a basic oxide like calcium oxide with ammonium chloride, an acidic salt. if you isolate exactly 100 g of NH3, but should have isolated 136 g in theory,...
-
What are the ethical implications of the following interpretations? This is a very fair arrangementa classic case of share the pain, share the gain. Besides, it gives Westlund-Deenihan some room to...
-
Create a data model for one of the processes in the end-of-chapter Exercises for Chapter 4. Explain how you would balance the data model and process model.
-
Show the result of each of the sample queries in Section 8.5 as it would apply to the database state in Figure 5.6. Figure 5.6 MPLOYE Sen 123456789 1965-01-09 731 Fondren, Houston, TX M 30000...
-
What is a statistical database? Discuss the problem of statistical database security.
-
What is flow control as a security measure? What types of flow control exist?
-
For the data set a. Find the first and third quartiles. b. Find the IQR. c. Find the upper and lower outlier boundaries. d. List all the values, if any, that are classified as outliers. 15 7 2 4 4 3...
-
For the data set a. Find the 58th percentile. b. Find the 22nd percentile. c. Find the 78th percentile. d. Find the 15th percentile. 2134 2 2 16 29 26 2 19 20 52 5 7 8 8 9 9 14 14 21 22 22 24 24 27...
-
For the data set a. Find the 80th percentile. b. Find the 43rd percentile. c. Find the 18th percentile. d. Find the 65th percentile. 1 20 20 5 00 8 8 23 24 25 81 8 11 13 14 14 15 15 15 15 16 17 25 26...
Study smarter with the SolutionInn App