Questions and Answers of Principles Of Database Management

E Recently, a new social network site, Facepage, was founded. Given the current trends, the managers of Facepage are convinced that this will be the new hype in the near future. When new users want
Consider this rule: “An employee of a department can never earn more than the manager of the department.” This is an example of a:a. Syntactical integrity rule.b. Semantical integrity rule.
Which of these is part of the query processor in the architecture of a DBMS?a. DDL compiler.b. DML compiler.c. Transaction manager.d. Security manager.
What are the key components of a DBMS architecture and how do they collaborate?
Which of these is not part of the storage manager in the DBMS architecture?a. Connection manager.b. Transaction manager.c. Buffer manager.d. Recovery manager.
What is the difference between procedural and declarative DML?
Which statement(s) is/are correct? Statement A: The DDL compiler compiles data definitions specified in DDL. It is possible that there is only one DDL with three instruction sets. Statement B: The
Given the ER model above, which of the following statements is correct?a. A movie can have as many lead actors as there are actors in the movie.b. PRODUCER is an existence-dependent entity
Which statement(s) is/are correct? Statement A: Native XML DBMSs map the hierarchical structure of an XML document to a physical storage structure, because they are able to use the intrinsic
In the movie ER model above, we focus on the binary relationship “PRODUCES”. Suppose we add an attribute type that indicates the time that each producer spent on producing each movie called
Fitness company “Conan” wants to set-up a database for its members and trainers. One of the aims is to record information about which members participated in which sessions and which trainers
Recently, the European Union made funds available to set-up a crossnational research database that stores information concerning scientific articles of researchers working at institutions in the EU.
Which statement is correct?a. In the case a ternary relationship type is represented as three binary relationship types, then semantics will get lost.b. A ternary relationship type can always be
One of your (hipster) acquaintances thinks he has the next billion-dollar startup idea for an app: Pizza Delivery with Entertainment. He heard from other people that you are following the course on
Which statements are correct?a. A weak entity type can only have one attribute type.b. A weak entity type is always existence-dependent.c. An existence-dependent entity type is always a weak
Given the following ER model:which statement is not correct?a. The ER model does not enforce that a supplier can only have purchase orders outstanding for products he/she can actually supply.b. The
Attracted by the success of Spotify, a group of students wants to build its own music streaming website called Musicmatic. Being economists, they are unaware of the specificities of databases and
Given the following EER specialization:which of the following statements is correct?a. A supermarket product can be a food and non-food product at the same time.b. There are certain supermarket
Given the following EER categorization: which statement is correct?a. All men and women are patients.b. A patient only inherits the “Name” and “Date of birth” attribute types from the
Which one of the following is an example of a disjoint and partial specialization?a. HUMAN → VEGETARIAN + NON-VEGETARIANb. HUMAN → BLONDE + BRUNETTEc. HUMAN → LOVES FISH + LOVES
Which of the following statements is correct?a. An aggregation cannot have attribute types.b. An aggregation cannot participate in a relationship type.c. An aggregation should both have attribute
Which statement is correct?a. A class is an instance of an object.b. A class only has variables.c. Inheritance is not supported in object orientation.d. Information hiding (also referred to as
Which variable types are not directly supported in UML?a. Composite variables.b. Multi-valued variables.c. Variables with unique values (similar to key attribute types in the ER model).d. Derived
Which of the following statements is not correct?a. In UML, access modifiers can be used to specify who can have access to a variable or method.b. A private access modifier (denoted by the symbol
Which statement is correct?a. An association is an instance of a link.b. Only binary associations are supported in the UML class diagram.c. An association is always bidirectional.d. Qualified
A composite aggregation…a. Has a maximum multiplicity of 1 and a minimum multiplicity of 0 or 1 at the composite side.b. Has a maximum multiplicity of n and a minimum multiplicity of 0 at the
Which statement is not correct?a. The changeability property specifies the type of operations that are allowed on either variable values or links.b. OCL constraints are defined in a procedural
Which of the following statements is correct?a. The catalog forms the heart of a database. It can be an integral part of the DBMS or a standalone component.b. The catalog makes sure the database
Discuss the importance of metadata modeling and catalogs.
A data steward notices that part of the database contains values in a different language. Which type of data quality error is this?a. Intrinsic.b. Contextual.c. Representational.d. Accessibility.
Define data quality and discuss why it is an important concept. What are the most important data quality dimensions? Illustrate with examples.
Is the following statement true or false? “The accuracy of a database depends on its representational and contextual characteristics.”a. True.b. False.
Discuss the Total Data Quality Management (TDQM) data governance framework and illustrate with examples.
Why can data incompleteness prove to be useful information?a. We can track down faults in the database model, such as updating errors that cause inconsistencies.b. We can track down the source of
Discuss and contrast the various roles in data management. Clearly indicate the key activities and skills required. Discuss which job profiles can be combined.
Which of the following statements is not correct?a. Subjectivity can cause data quality issues.b. Consistency issues can arise due to sharing data across multiple departments.c. Data quality can
Contrast the hierarchical model with the CODASYL model in terms of• Attribute types supported;• Relationship types and cardinalities supported.
A bank needs to store the following information: customer names, customer addresses, city of a branch, number of accounts, account IDs, and account balances. How many record types do you need to
Make a hierarchical and CODASYL model for the fitness company “Conan” discussed in Chapter 3. Contrast both models and discuss their limitations. Give examples of semantics that cannot be
If a hierarchical model contains N:M relationship types that have been integrated by repeating the child nodes where necessary, what are the dangers of updating the database?a. Slower retrieval of
Consider the following (normalized) relational model (primary keys are underlined, foreign keys are in italics). EMPLOYEE(SSN, ENAME, EADDRESS, SEX, DATE OF BIRTH, SUPERVISOR, DNR) SUPERVISOR:
The human resources department of a university wants to make sure that every course has exactly one main professor. How can they implement this constraint using the CODASYL framework?a. They
In CODASYL, a multi-valued composite attribute type can be represented as a …a. record type.b. data item.c. vector.d. repeated group.
A library database records the authors and the publisher of each book. Normalize the following relation and indicate the primary and foreign key attribute types:R (ISBN, title, author(name,
How can the CODASYL framework correctly model a family tree, taking into account that every child has to have (at least) two parents?a. Use a set type “is parent of” between record types
Given the following assumptions: normalize the following relation:Flight (Flightnumber, Flighttime, airline (airlinename), passenger (passengername, gender, date of birth), pilot (pilotname, gender,
Which of the following statements is correct?a. A foreign key of a relation A cannot refer to the primary key of the same relationA. b. A relation cannot have more than one foreign key.c. Every
Given the following EER model for an electricity market:• Discuss some examples of semantics that cannot be enforced by the EER model;• Map the model to a relational model representation. Discuss
Consider a data model for the Olympics storing information about countries and athletes. There is a 1:N relationship type between country and athlete and an athlete always has to belong to exactly
The following relational model represents an HRM system of a consultancy firm. The primary keys are underlined; foreign keys are in italic font.Suppose a new consultant is hired and immediately
Given the following EER model for an airline business: • Discuss some examples of semantics that cannot be enforced by the EER model;• Map the model to a relational model representation. Discuss
Consider the following (normalized) relational model (primary keys underlined; foreign keys in italics):a. A department always has exactly one manager.b. Every employee must always be supervised by
Given the following EER model for a driving school company: • Discuss some examples of semantics that cannot be enforced by the EER model;• Map the model to a relational model representation.
Consider the following relational model (primary keys are underlined, foreign keys in italics):a. The model does not allow a course to be taught by multiple professors.b. The model can be further
A relation is in 3 NF if it satisfies 2 NF and …a. No non-prime attribute type of R is transitively dependent on the primary key.b. No prime attribute type of R is transitively dependent on the
Consider the following generalization/specialization.1. The relational model does not allow one to enforce the completeness constraint; the disjointness constraint can be enforced.2. The relational
Which statement is correct?a. The Boyce–Codd normal form is more strict than the fourth normal form.b. The Boyce–Codd normal form is more strict than the third normal form.c. The second normal
Consider the following EER model.Which statement is correct? a. When mapping the EER relationship type IS_ENROLLED between COURSE and STUDENT to the relational model, a new relation needs to be
Consider the following ER model for a course administration.Which statement is not correct?a. When mapping the ER relationship type teaches between Session and Teacher to the relational model, a new
The following table with purchase orders is created:What happens upon deletion of a supplier?a. All purchase order records tied to that supplier are also deleted.b. The SUPNR of this supplier is
Write an SQL query that retrieves each supplier who can deliver product 0468 within one or two days, accompanied by the price of the product and the delivery period.
We’re interested in wine stores. Therefore, we want to retrieve the SUPNR and SUPNAME of each store which contains “wine” in its store name. Which of the following queries can we use?WHERE
Take the following extract from SUPPLIES:We want to retrieve the fastest delivery time for product 0185. We type the following query:What are the results? If you believe the query is correct, select
Write an SQL query that returns the average price and variance per product.
Consider the following query: Which of the following answers is correct? SELECT * FROM PRODUCT WHERE PRODTYPE='red' ORDER BY AVAILABLE_QUANTITY DESC, PRODNAME
Write an SQL query that retrieves all pairs of suppliers who supply the same product, along with their product purchase price if applicable.
Write a nested SQL query to retrieve the supplier name of each supplier who supplies more than five products.
We want to retrieve all unique supplier numbers and statuses of suppliers who have at least one outstanding purchase order. Which query is correct? a. b. C. d. SELECT DISTINCT R.SUPNR,
Write an SQL query to retrieve the supplier number, supplier name, and supplier status of each supplier who has a higher supplier status than supplier number 21.
Consider the following query:Which of the following statements is not correct?a. The query retrieves the product number, product name, and available quantity of each product thanks to the left outer
Which of the following queries selects the name of the supplier, corresponding order number, and total ordered quantity of the order that has the maximum total quantity ordered. a. SELECT R1.SUPNAME,
Write a correlated SQL query to retrieve the number and status of all suppliers, except for the three suppliers with the lowest supplier status.
Consider following query:The query retrieves:a. The number and name of all products that can only be supplied by one supplier.b. The number and name of all products that cannot be supplied by any
Write a correlated SQL query to retrieve all cities with more than one supplier.
Write an SQL query to retrieve name, number, and total outstanding orders of all suppliers that have outstanding orders, except for the supplier(s) with the fewest outstanding orders.
Consider the following SQL query:This query selects:a. The supplier name, supplier address, and supplier city of all suppliers who cannot supply any products.b. The supplier name, supplier address,
Write an SQL query using EXISTS to retrieve the supplier numbers and names of all suppliers that do not have any outstanding orders.
Consider the following query:The query retrieves:a. The name and number of the product with the highest ordered quantity.b. The name and number of all products that are ordered and do not exceed
Create a view SUPPLIEROVERVIEW that retrieves, for each supplier, the supplier number, the supplier name, and the total amount of quantities ordered. Once created, query this view to retrieve
Consider following query:The output of the query represents:a. A table summarizing for each product the increase in stock after the ordered products are delivered.b. A table summarizing for each
Write an SQL query that retrieves the total available quantity of sparkling wines. Make sure to display this quantity as “TOTAL_QUANTITY”.
Given the task to retrieve the numbers of all suppliers who can supply products 0832 and 0494, which query is correct? a. SELECT DISTINCT SUPNR FROM SUPPLIES WHERE PRODNR IN (0832, 0494) b. SELECT
Write a query to select all supplier numbers, together with their supplier name and total number of outstanding orders for each supplier. Include all suppliers in the result, even if there are no
Consider the following View definition and update statement:What will be the result of this?a. The update can be successfully made but only the PRODUCT table will be updated.b. The update can be
Write an SQL query that returns the SUPNR and number of products of each supplier who supplies more than five products.
Compare the following two queries:Which of the following statements is correct?a. Result query 1 is always = result query 2 because PURCHASE_ORDER contains only unique purchase orders.b. Result
Write an SQL query that reports the average delivery time for each supplier who supplies products.
Consider the following query: What is the result?a. The query returns the PRODNR and average QUANTITY of each purchase order that has fewer than 15 purchase order lines.b. The query returns the
Write a nested SQL query to retrieve all purchase order numbers of purchase orders that contain either sparkling or red wine.
Consider the following query:What is the result?a. The query retrieves the product name of each product that has a supplier in New York or Washington.b. The query retrieves the product name of each
Write a correlated SQL query to retrieve the three lowest product numbers.
Write an SQL query with ALL or ANY to retrieve the name of the product with the highest available quantity.
We want to retrieve the available quantity of each ordered product of supplier Ad Fundum. Which of the following queries is correct? a. SELECT PRODNR, AVAILABLE_QUANTITY FROM PRODUCT WHERE PRODNR
Discuss the following collection types: set, multiset, list, and array. Illustrate with examples.
What is the impact of ORDBMSs on normalization?
Which statement about “Encapsulation” is correct?a. Encapsulation refers to storing a value in a variable, and never changing it again. This way its value is safe forever.b. Encapsulation
What is the relationship between polymorphism and dynamic binding? Illustrate with an example.
Consider the following query:The query selects:a. The name and total number of outstanding orders of all suppliers that have at least one outstanding order.b. The name and total number of
Which of the following statements is not correct?a. Objects are blueprints of classes. “Human”, “Employee”, and “Sale” are examples of objects.b. Objects are instances of classes. The
Consider following query:and the following statements:1. For each product, the supplier number of the supplier who can supply the product for the cheapest price is retrieved.2. For each product,

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