Midterm Chapters 1, 2, 3 and 5
What will result from the following SQL Select statement? SELECT MIN(Product_Description) FROM Product_V;
The first product description alphabetically in Product_V will be shown.
The SDLC phase in which the detailed conceptual data model is created is the (Blank) phase.
analysis
The logical representation of an organization's data is called a(n):
entity-relationship model.
A relationship where the minimum and maximum cardinality are both one is a(n) Blank relationship.
mandatory one
Which of the following is the wildcard operator in SQL statements?
( * )
For the relationship represented in the figure below, which of the following is true?
A department can have more than one employee.
What will be returned when the following SQL statement is executed? SELECT driver_no, count (*) as num_deliveries FROM deliveries WHERE state = 'MA' GROUP BY driver_no;
A listing of each driver who made deliveries to state = 'MA' as well as the number of deliveries that each driver has made to that state
In the figure shown below, which of the following is true?
A person can marry at most one person
Attribute
A property or characteristic of an entity or relationship type that is of interest to the organization.
Binary relationship
A relationship between the instances of two entity types.
Ternary relationship
A simultaneous relationship among the instances of three entity types.
In the following diagram, which is true?
All of the above: it depicts a unary relationship it depicts a many-to-many relationship there is an associative entity
Which of the following criteria should be considered when selecting an identifier? All of the above:choose an identifier that will not be nullchoose an identifier that doesn't have large composite attributeschoose an identifier that is stable
All of the above: choose an identifier that will not be null. choose an identifier that doesn't have large composite attributes. choose an identifier that is stable.
In the figure below, which attribute is multivalued?
Skill
What result set is returned from the following query? SELECT Customer_Name, telephone FROM customers WHERE city in ('Boston','New York','Denver');
The Customer_Name and telephone of all customers living in either Boston, New York or Denver
Which of the following is true of the order in which SQL statements are evaluated?
The SELECT clause is processed before the ORDER BY clause.
A person is an example of an entity
True
A universal data model is a generic or template data model that can be reused as a starting point for a data modeling project.
True
An extranet uses Internet protocols to establish limited access to company data by the company's customers and suppliers.
True
Applications can be moved from one machine to another when each machine uses SQL.
True
Data from prior systems is converted to the new system during the implementation phase of the systems development life cycle.
True
Data management technologies are also increasing often used as information systems, as a foundation for analytics or the systematic analysis of data to understand a real-world problem better.
True
A rule that CANNOT be violated by database users is called a:
constraint
The number of entity types that participate in a relationship is called the:
degree
An attribute that can be calculated from related attribute values is called a(n) _____ attribute.
derived
The total quiz points for a student for an entire semester is a(n) _____ attribute.
derived
An attribute of an entity that is computed is a(n):
derived attribute.
Specifying how data from a logical schema are stored in secondary memory is part of the:
design
Customers, cars, and parts are examples of:
entities
When identifying the parts of the packaged data model that apply to your organization, one should first start with:
entities.
A person, place, object, event, or concept about which the organization wishes to maintain data is called a(n):
entity
In the following diagram, which answer is true?
Each employee can supervise one to many employees.
Program-data dependence is caused by:
file descriptions being stored in each database application.
A database is an organized collection of (Blank) related data.
logically
A student can attend five classes, each with a different professor. Each professor has 30 students. The relationship of student to professors is a _____ relationship.
many-to-many
According to a McKinsey Global Institute Report, in 2010 alone, global enterprises stored more than:
more than 7 billion exabytes of data.
Blank do NOT concentrate on determining the requirements for the database component of an information system.
End Users
A relational database establishes the relationships between entities by means of a common field.
False
A relationship instance is an association between entity instances where each relationship instance includes exactly one entity from each participating entity type.
False
A subtype is a generic entity that has a relationship with one or more entities at a lower level.
False
A well-structured database establishes the entities between relationships in order to derive the desired information.
False
COUNT (*) tallies only those rows that contain a value, while COUNT counts all rows.
False
Data redundancy is used to establish relationships between data but is never used to improve database performance.
False
Database development begins with the design of the database.
False
Generalization is a top-down process.
False
In databases, null values are equivalent to zero.
False
In multi-tier database architectures, little functionality needs to be programmed into the client application.
False
Most systems developers believe that data modeling is the least important part of the systems development process.
False
The CREATE SCHEMA DDL command is used to create a table.
False
The DELETE TABLE DDL command is used to remove a table from the database.
False
The HAVING clause and the WHERE clause perform the same operation.
False
The intent of a business rule is to break down business structure.
False
The physical structure and storage organization of the database is decided upon during the implementation phase of the systems development life cycle.
False
The relational data model is no longer popular in the 21st century.
False
Visual programming tools such as Visual Basic have made prototyping more difficult.
False
With the traditional file processing approach, each application shares data files, thus enabling much data sharing.
False
The Blank rule states that an entity instance can simultaneously be a member of two (or more) subtypes.
overlap
The Blank rule specifies that an entity instance of a super type is allowed not to belong to any subtype.
partial specialization
In the following diagram, which of the answers below is true?
patient has one or more patient histories.
Requiring a CustomerID to exist in a Primary table before it can exist in a foreign table is an example of:
referential integrity.
An attribute that must have a value for every entity (or relationship) instance is a(n):
required attribute
In prototyping, implementation and maintenance activities are repeated as necessary until the product is correct.
True
Multi-tier client/server database applications contain a business logic layer.
True
An attribute of the super type that determines the target subtype(s) is called the:
subtype discriminator.
Prototyping is a type of rapid application development.
True
Redundancy increases the risk of inconsistent data.
True
Separation of metadata from application programs that use the data is called data independence.
True
The E-R model is used to construct a conceptual model.
True
The ORDER BY clause sorts the final results rows in ascending or descending order.
True
The data repository assists database administrators in enforcing standards.
True
The failure to implement a strong database administrative function is the most common source of database failures in organizations.
True
The following query totals sales for each salesperson. SELECT salesperson_id, sum(sales) FROM salesperson GROUP BY salesperson_id.
True
The following query totals sales for each salesperson. SELECT salesperson_id, sum(sales) FROM salesperson GROUP BY salesperson_id;
True
The relationship between the instances of two entity types is called a binary relationship.
True
The systems development life cycle is the traditional methodology used to develop, maintain, and replace information systems.
True
While business rules are not redundant, a business rule can refer to another business rule.
True
A fact is an association between two or more:
terms
In an E-R diagram, there are/is Blank business rule(s) for every relationship.
two
A relationship between the instances of a single entity type is called a Blank relationship.
unary
A generic or template data model that can be reused as a starting point for a data modeling project is called a(n):
universal data model.
Because applications are often developed independently in file processing systems:
unplanned duplicate data files are the rule rather than the exception.
Languages, menus, and other facilities by which users interact with the database are collectively called a(n):
user interface.
A data warehouse derives its data from:
various operational data sources.
A good data definition will describe all of the characteristics of a data object EXCEPT:
who can delete the data
A business rule is a statement that defines or constrains some aspect of the business.
True
A good data definition is always accompanied by diagrams, such as the entity relationship diagram.
True
E. F. Codd developed the relational model in the:
1970s
Simple (or atomic) attribute
An attribute that cannot be broken down into smaller components that are meaningful to the organization.
Composite attribute
An attribute that has meaningful component parts (attributes).
Optional attribute
An attribute that may not have a value for every entity (or relationship) instance with which it is associated.
Multivalued attribute
An attribute that may take on more than one value for a given entity (or relationship) instance.
Required attribute
An attribute that must have a value for every entity (or relationship) instance with which it is associated.
Derived attribute
An attribute whose values can be calculated from related attribute values.
Associative entity
An entity type that associates the instances of one or more entity types and contains attributes that are peculiar to the relationship between those entity instances.
Weak entity type
An entity type whose existence depends on some other entity type.
Which of the following counts ONLY rows that contain a value?
COUNT
What does the following SQL statement do? UPDATE Product_T SET Unit_Price = 775 WHERE Product_ID = 7
Changes the unit price of Product 7 to 775.
Which of the following is a technique for optimizing the internal performance of the relational data model?
Clustering data
Which of the following can produce scalar and vector aggregates?
Group By
Which of the following is NOT a cost and/or risk of the database approach?
Improved responsiveness
Which of the following is NOT an advantage of database systems?
Redundant data
Which of the following is NOT a good characteristic of a data name?
Relates to a technical characteristic of the system
Blank are established between entities in a well-structured database so that the desired information can be retrieved.
Relationships
Which of the following is true of packaged data models?
Relationships are connected to the highest-level entity type in an order that makes sense.
Identifying owner
The entity type on which the weak entity type depends.
What will result from the following SQL Select statement? SELECT MIN(Product_Description) FROM Product_V;
The first product description alphabetically in Product_V will be shown.
The most common source of database failures in organizations is:
The most common source of database failures in organizations is:
Identifying relationship
The relationship between a weak entity type and its owner
What results will be produced by the following SQL query?
The total price of all products that are of type wood.
What results will be produced by the following SQL query? SELECT SUM(Standard_Price) as Total_Price FROM Product_V WHERE Product_Type = 'WOOD';
The total price of all products that are of type wood.
In the figure below, which attribute is derived?
Years_Employed
The SDLC phase in which the detailed conceptual data model is created is the Blank phase.
analysis
In a file processing environment, descriptions for data and the logic for accessing the data are built into
application programs.
An entity name should be all of the following EXCEPT:
as short as possible
An entity type name should be all of the following EXCEPT:
as short as possible.
The property by which subtype entities possess the values of all attributes of a super type is called:
attribute inheritance.
