Question: Why is it desirable to have a key be unique?

Why is it desirable to have a key be unique?

Step by Step Solution

★★★★★

3.43 Rating (153 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock

If there were several values for ... View full answer

blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Students Have Also Explored These Related Database Design Using Entity Relationship Diagrams Questions!

Q:

Why is it desirable to have the feet working only when the hands are occupied?

Q:

Why is it desirable to start thinking about jobs monthseven yearsbefore youll actually be on the market?

Q:

The concentration of a solution is measured six times by one operator using the same instrument. She obtains the following data: 63.2, 67.1, 65.8, 64.0, 65.1, and 65.3 (grams per liter). (a)...

Q:

What does it mean to say a field has unique values? Why is it desirable to have a key be unique?

Q:

Qestion: Reflect upon the desirable characteristics of a primary key that were presented in this weeks lecture. Choose one characteristic and discuss why you believe it would be undesirable if this...

Q:

the following relational algebra questions based on tables S1 and S2 (below) Question 1 What is the output of S1 S2 ? The row identified by sid 22 The rows identified by sid 31 and 58 The row...

Q:

Mr. Williams, the leather handbag buyer for an upscale menswear specialty retailer located in San Francisco, decides to review his vendor analysis report before making his forthcoming seasons...

Q:

PLEASE HELP I NEED IT. A. Lab #3 - Using Constraints Overview 1. This lab will introduce you to using constraints within a table. 2. What is Constraint? a. A constraint is a restriction placed on one...

Q:

Can you please format the answers like the example below: This is the book we use Fundamentals of Database Systems (Subseription) Shamkant B. Navathe, Ramez Elms This is the eBook of the prin codes,...

Q:

CHAPTER 3 1. Which of the following is a correct statement? a. You can restore the data deleted with the DROP COLUMN clause, but not the data deleted with the SET UNUSED clause. b. You cant create...

Q:

Use the information in Exercise 2-13 to prepare an August statement of owners equity for Tech Today. (The owner invested $84,000 cash in the company during the first week of August.)

Q:

In Review Question, instead of testing a hypothesis, you might prefer to construct a confidence interval for the mean weight of all 2-pound boxes of candy during a recent production shift. (a) Given...

Q:

5. An investor is thinking about buying some shares of FinComm-I at $60 a share. She expects the price of the stock to rise to $100 a share over the next 3 years. During that time, she also expects...

Q:

Which of the following procedures, by itself, is most effective at preventing employees from stealing cash? a. Restrictively endorsing all checks from customers upon receipt b. Having someone who has...

Q:

What is the Nyquist sampling rate for each of the following signals? a. A low-pass signal with bandwidth of 200 KHz? b. A band-pass signal with bandwidth of 200 KHz if the lowest frequency is 100 KHz?

Q:

What is the result of scrambling the sequence 11100000000000 using each of the following scrambling techniques? Assume that the last non-zero signal level has been positive. a. B8ZS b. HDB3 (The...

Q:

The input stream to a 4B/5B block encoder is 0100 0000 0000 0000 0000 0001 Answer the following questions: a. What is the output stream? b. What is the length of the longest consecutive sequence of...

Q:

Write MATLAB code to calculate the 5 fifth roots of - 1 .

Q:

I need help on these as soon as possible please!! Required information [The following information applies to the questions displayed below.] Martinez Company's relevant range of production is 7,500...

Q:

A company wants to determine how to decrease employee turnover. In order to do this, they test whether paying off an employees student debt will cause fewer employees to leave. The analytic testing...