INSY 3304 EXAM 1
The object-oriented data model was developed in the _____.
1980s
At the implementation level, the supertype and its subtype(s) depicted in a specialization hierarchy maintain a(n) _____ relationship.
1:1
The _____ relationship should be rare in any relational database design.
1:1
Data warehouse routinely uses _____ structures in its complex, multilevel, multisource data environment.
2NF
To generate a surrogate key, Microsoft Access uses a(n) _____ data type.
AutoNumber
_____ are normally expressed in the form of rules.
Constraints
A(n) _____ is the set of possible values for a given attribute.
Domain
Which of the following is a specialization hierarchy disjoint constraint scenario in case of partial completeness?
Each supertype occurrence is a member of at least one subtype.
A subtype contains attributes that are common to all of its supertypes.
False
An advantage of database systems is that you needn't perform frequent updates and apply latest patches.
False
Character data can contain any character or symbol intended for mathematical manipulation.
False
Database designers determine the data and information that yield the required understanding of the entire business.
False
Database programming languages receive all application requests and translate them into the complex operations required to fulfill those requests.
False
In Chen notation, entities and relationships have to be oriented horizontally; not vertically.
False
In a natural join, the column on which the join was made occurs twice in the new table.
False
In an SQL-based relational database, each table is dependent on every other table.
False
In implementation terms, an entity is existence-dependent if it has a mandatory primary key.
False
Normalization purity is often easy to sustain in the modern database environment.
False
One advantage of a database system over previous data management approaches is that the database system is considerably less complex.
False
The Crow's Foot notation easily identifies multivalued attributes.
False
The hierarchical model is software-independent.
False
The one-to-many (1:M) relationship is easily implemented in the relational model by putting the foreign key of the "1" side in the table of the "many" side as a primary key.
False
The order of the rows and columns is important to the DBMS.
False
Within a specialization hierarchy, a supertype can exist only within the context of a subtype.
False
_____ is the bottom-up process of identifying a higher-level, more generic entity supertype from lower-level entity subtypes.
Generalization
In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable.
Keys
Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed only once in the _____ relationship.
M:N
_____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.
M:N
_____ provide a description of the data characteristics and the set of relationships that link the data found within the database.
Metadata
The _____ constraint can be placed on a column to ensure that every row in the table has a value for that column.
NOT NULL
When the specific cardinalities are not included on the diagram in Crow's Foot notation, cardinality is implied by the use of _____.
Symbols
Which of the following is true of NoSQL databases?
They are not based on the relational model.
A data model is usually graphical.
True
A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind.
True
A table is in fourth normal form if it is in third normal form and has no independent multivalued dependencies.
True
A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.
True
An entity in the entity relationship model corresponds to a table in the relational environment.
True
An implementation-ready data model should contain a description of the data structure that will store the end-user data.
True
At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a 1:1 relationship.
True
Connectivities and cardinalities are established by concise statements known as business rules.
True
In an SQL-based relational database, rows in different tables are related based on common values in common attributes.
True
In order to meet performance requirements, portions of the database design may need to be occasionally denormalized.
True
In the context of data models, an entity is a person, place, thing, or event about which data will be collected and stored.
True
In the context of partial dependencies, data redundancies occur because every row entry requires duplication of data.
True
In the entity relationship model, a table row corresponds to an entity instance.
True
Metadata describe the data characteristics and the set of relationships that links the data found within the database.
True
Relational algebra defines the theoretical way of manipulating table contents using relational operators.
True
Relational models view data as part of a table or collection of tables in which all key values must be identified.
True
The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor and one two-column table (e.g., columns "a" and "b") as the dividend.
True
The combination of normalization and ER modeling yields a useful ERD, whose entities can be translated into appropriate table structures.
True
The objective of normalization is to ensure that each table conforms to the concept of well-formed relations.
True
Oracle 12c, MS SQL Server, and Tamino are examples of _____ data models.
XML Hybrid
An entity cluster is formed by combining multiple interrelated entities into _____.
a single entity object
A partial completeness constraint is represented by _____.
a single horizontal line under a circle
Improving _____ leads to more flexible queries.
atomicity
To simplify the conceptual design, most higher-order relationships are decomposed into appropriate equivalent _____ relationships whenever possible.
binary
BCNF can be violated only if the table contains more than one _____ key.
candidate
The database structure in a DBMS is stored as a _____.
collection of files
A(n) _____ is a restriction placed on the data.
constraint
A derived attribute is indicated in the Chen notation by a _____ that connects the attribute and an entity.
dashed line
A(n) _____ enables a database administrator to describe schema components.
data definition language (DDL)
The extended entity relationship model (EERM) is sometimes referred to as the _____.
enhanced entity relationship model
A noun in a business rule translates to a(n) _____ in the data model.
entity
A(n)_____ is a generic entity type that is related to one or more entity subtypes.
entity supertype
The default comparison condition for the subtype discriminator attribute is the _____ comparison.
equality
An entity is said to be _____-dependent if it can exist in the database only when it is associated with another related entity occurrence.
existence
In a real-world environment, we must strike a balance between design integrity and _____.
flexibility
In organizations that generate large number of transactions, _____ are often a top priority in database design.
high processing speeds
The property of _____ enables an entity subtype to inherit the attributes and relationships of the supertype.
inheritance
A table is in 4NF if it is in 3NF, and _____.
it has no multivalued dependencies
In a _____ situation, one key determines multiple values of two other attributes and those attributes are independent of each other.
multivalued dependency
If one exists, a data modeler uses a _____ as the primary key of the entity being modeled.
natural identifier
Overlapping subtypes are subtypes that contain _____ subsets of the supertype entity set.
nonunique
The most likely data type for a surrogate key is _____.
numeric
A data warehouse contains historical data obtained from the _____.
operational databases
If Tiny College has some departments that are classified as "research only" and do not offer courses, the COURSE entity of the college database would be _____ the DEPARTMENT entity.
optional to
In the context of total completeness, in a(n) _____, every supertype occurrence is a member of at least one subtype.
overlapping constraint
Dependencies based on only a part of a composite primary key are known as _____ dependencies.
partial
One important inheritance characteristic is that all entity subtypes inherit their _____ key attribute from their supertype.
primary
An attribute that is part of a key is known as a(n) _____ attribute.
prime
A _____ is a logically connected set of one or more fields that describes a person, place, or thing.
record
A relational table must not contain a(n) _____.
repeating group
Most data that can be encountered are best classified as _____.
semistructured
According to the "preferably single-attribute" characteristic of a primary key, the primary key:
should have the minimum number of attributes possible.
When a table contains only one candidate key, _____ are considered to be equivalent.
the 3NF and the BCNF
Normalization works through a series of stages called normal forms. For most purposes in business database design, _____ stages are as high as you need to go in the normalization process.
three
Nonoverlapping subtypes are subtypes that contain a(n) _____ subset of the supertype entity set.
unique
The "_____" characteristic of a primary key states that the primary key must uniquely identify each entity instance, must be able to guarantee unique values, and must not contain nulls.
unique values
