Suppose there are two relations r and s, such that the foreign key B of r references

Question:

Suppose there are two relations r and s, such that the foreign key B of r references the primary key A of s. Describe how the trigger mechanism can be used to implement the on delete cascade option, when a tuple is deleted from s.

Fantastic news! We've Found the answer you've been seeking!

Step by Step Answer:

Related Book For book-img-for-question

Database System Concepts

ISBN: 978-0072554816

4th Edition

Authors: Henry F. Korth, S. Sudarshan

See More Books

Question Posted: Jan 28, 2011 05:54 AM

See More Questions

Describe how effective job analysis can be used to satisfy each of the following statutes:
Describe how the bullwhip measure can be used to analyze supply chains.
Describe how the five forces can be used to determine the average expected profitability in an industry.
The CEO of Amazon, has publicly questioned the advisability of granting patents for business processes such as his companys 1-Click ordering process. Do such patents put a chilling effect on the...
Ruby Company manufactures and sells a single product. The company's sales and expenses for last year follow: Requirements 1. Fill in the missing numbers in the preceding table. Use the following...
Draw a project network from the following information. What activity(s) is a burst activity? What activity(s) is a merge activity? Predecessor Description ID None Identify topic A Research topic...
Models of transformational leadership treat the leader as a hero who can (singlehandedly) turn the organisation around and deliver it from a crisis, whereas empowering and post-heroic leadership...
Which, if any, of the following scenarios would support an employees claim of discrimination on the basis of national origin? a. A Dominican chambermaid in a hotel is denied promotion to front-desk...
The disadvantages of the Dividend Growth Model are: 1. Its Complicated 2. It does not explicitly consider risk 3. Sensitive to growth rates 4. Its difficult to use 5. Only applies to companies that...
A Gallup poll indicated that 20% of Americans had confidence in U.S. banks. Interestingly, 58% also said that they had confidence in their main or primary bank. (data extracted from D. Jacobs,...
SQL allows a foreign-key dependency to refer to the same relation, as in the following example: create table manager (employee-name char (20), manager-name char(20), primary key employee-name,...
Write an assertion for the bank database to ensure that the assets value for the Perryridge branch is equal to the sum of all the amounts lent by the Perryridge branch.
Pop (with the same properties as water) flows from a 4-in.-diameter pop container that contains three holes as shown in Fig. P3.103 (see Video 3.9). The diameter of each fluid stream is \(0.15...
4. What is the time complexity of the following procedure for in/2 to n do j 2 end for while (j
If the concentration of a constituent in the influent to the equalization basin is constant over the 24 h period, will the load of the constituent from the basin be constant? If the concentration of...
A three-phase transmission line of a 60 Hz circuit has a length of 370 km (230 miles). the conductors are of the 795,000cm (54/7) type with horizontal spacing of 25 feet between them. The load on the...
Simulate rolling a dice using Math.random() . Your roll function should allow the caller to specify any number of sides, but default to 6 if no side count is given: roll() assumes a 6 sided dice,...
Drama Read the excerpt from a play. Then, answer the question(s). (1) (2) Belle: Having trouble deciding what will make you look like both a power to be reckoned with and a fetching young lady while...
Follow up with details of what the recipient has to do; and
Define relevant costs and discuss: (1) whether all future costs are relevant for decision making and (2) whether variable costs are always relevant and fixed costs are always irrelevant
The decomposition of cyclohexane to benzene and hydrogen is mass transfer-limited at high temperatures. The reaction is carried out in a 5-cm-ID pipe 20 m in length packed with cylindrical pellets...
What is multifactor authentication? How does it help safeguard against stolen passwords?
Consider the Oracle Virtual Private Database (VPD) feature described in Section 9.8.5 and an application based on our university schema. a. What predicate (using a subquery) should be generated to...
A database relation may have the values of certain attributes encrypted for security. Why do database systems not support indexing on encrypted attributes? Using your answer to this question, explain...
Suppose you bought a bon with an annual coupon rate of 6.5 percent one year ago for $1,032. The bond sells for $1,020 today. a. Assuming a $1,000 face value, what was your total dollar return on this...
During the year 2021, William has a job as an accountant, he earns a salary of $100,000. He has done some cleaning services work on his own (self-employed), where he earned a net income of $50,000....
Fixed cost per unit is $7 when 25,000 units are produced and $5 when 35,000 units are produced. What is the total fixed cost when 30,000 units are produced? Group of answer choices $150,000....

Suppose there are two relations r and s, such that the foreign key B of r references

Question:

Step by Step Answer:

We define triggers for each relation whose primaryk...View the full answer

Database System Concepts

Students also viewed these Computer Sciences questions