Question 1

The basic relationships among entities are: one-to-many, many-to-many, and one-to-one.

Accepted Answer

This statement is true as the basic relationships among entities in a database can be categorized into these three types namely: one-to-many, many-to-many, and one-to-one.

Question 2

A surrogate key is a primary key that consists of a column that uniquely identifies an entity.

Accepted Answer

A surrogate key is a primary key that is not derived from the entity's natural attributes.

Question 3

If you find that more than one table in your cumulative design has the same primary key, you should combine the tables to form a new table.

Accepted Answer

In a relational database, primary key uniquely identifies each record in the database. If multiple tables have the same primary key, it means that there is a redundancy in data and this can cause data inconsistencies and errors. To avoid this, the tables should be combined into a new table with a single primary key.

Question 4

A weak entity is an entity that depends on another entity for its own existence.

Accepted Answer

A weak entity is one that cannot be uniquely identified by its own attributes alone and requires a foreign key relationship with another entity to exist. Therefore, it depends on another entity for its own existence.

Question 5

When the user views are not clearly defined, you should consider each stated requirement as a separate user view.

Accepted Answer

When user views are not clearly defined, it is important to consider each stated requirement as a separate user view in order to ensure that all potential user needs are addressed. This approach can help to prevent important features or functionality from being overlooked, and can help to ensure that the final product meets the needs of a wide range of users.

Question 6

After you have completed the first two steps for a given user view, you can merge the results into the cumulative design.

Accepted Answer

The answer of After you have completed the first two...

Question 7

The first substep in representing the user view as a collection of tables is to determine entities and create a table for each.

Accepted Answer

This is true. The first step in representing the user view as tables involves identifying entities, such as customers or orders, and creating a table for each entity. Each table will then have columns representing attributes or characteristics of the entity.

Question 8

If no unique identifier is available for an entity, you can go without one.

Accepted Answer

A unique identifier is important for identifying and distinguishing an entity from others. If no unique identifier is available, it may lead to confusion and errors in the system. Therefore, it is recommended to create a unique identifier, even if it means using a combination of multiple attributes to form it.

Question 9

A foreign key is a column or collection of columns in one table that is required to match the value of the primary key for some row in another table, or be null.

Accepted Answer

This is the definition of a foreign key.

Question 10

If each employee works in a single department, and each department has only one employee, the relationship between employees and departments is a one-to-many relationship.

Accepted Answer

The relationship described is one-to-one, as each employee is associated with exactly one department, and each department has exactly one employee.

Question 11

A design that supports all user views is called a constructive design.

Accepted Answer

A design that supports all user views is called a universal design. A constructive design is a design that involves building or creating something.

Question 12

The simplest way to implement a one-to-one relationship is to treat it as a one-to-many relationship.

Accepted Answer

A one-to-one relationship can be implemented as a one-to-many relationship by adding a unique constraint to the foreign key column in the child table. This ensures that each row in the child table can only be associated with one row in the parent table.

Question 13

The first step in creating a user view is to normalize the collection of tables.

Accepted Answer

The first step in creating a user view typically involves understanding the user's requirements and the specific data they need access to, rather than normalizing the collection of tables, which is a step in database design focused on organizing data to reduce redundancy and improve data integrity.

Question 14

You create a many-to-many relationship by creating a new table whose primary key is the combination of the primary keys of the original tables.

Accepted Answer

This is correct. The new table will have foreign keys that reference the primary keys of the original tables, allowing for a many-to-many relationship to be established.

Question 15

When combining third normal form tables, the resulting table will not be in third normal form when a column A in one user view determines a column B in a second user view, yet column A is not a column in the second user view.

Accepted Answer

This is a violation of transitive dependency, which means the resulting table will not be in third normal form.

Question 16

In a one-to-many relationship, the primary key of the "many" table becomes the foreign key of the "one" table.

Accepted Answer

In a one-to-many relationship, the primary key of the "one" table is used as a foreign key in the "many" table to establish the relationship.

Question 17

The information-level design methodology is completed independently of any particular DBMS that the organization will ultimately use.

Accepted Answer

Information-level design methodology is a conceptual and independent process that focuses on identifying the information needs of the organization, designing data structures, and establishing relationships among the data elements, regardless of the specific database management system (DBMS) to be used.

Question 18

When determining the primary key of a table you must decide what properties are required to uniquely identify an entity.

Accepted Answer

The primary key of a table must be able to uniquely identify each record/row in the table, and thus, the properties required for identification must be identified.

Question 19

In an entity-relationship diagram, rectangles represent foreign keys.

Accepted Answer

Rectangles in an entity-relationship diagram represent entities, not foreign keys. Foreign keys are represented by lines connecting one entity to another.

Question 20

When you combine third normal form tables, the result will always be in third normal form.

Accepted Answer

Combining third normal form tables can introduce transitive dependencies or other forms of redundancy, potentially violating the rules of third normal form.

Quiz 6: Database Design 2: Design Method