BCIS 4620 Exam 1 Q 1-5

To simplify the conceptual design, most higher-order relationships are decomposed into appropriate equivalent _____ relationships whenever possible.

binary

Another name for a composite entity is a(n) _____ entity.

bridge

A _____ key can be described as a minimal superkey, a superkey without any unnecessary attributes.

candidate

Each table _____ represents an attribute.

column

A _____ attribute can be further subdivided to yield additional attributes.

composite

The entity relationship diagram (ERD) represents the _____ database as viewed by the end user.

conceptual

The first step in building an entity-relationship diagram (ERD) is _____.

creating a detailed narrative of the organization's description of operations

A derived attribute is indicated in the Chen notation by a _____ that connects the attribute and an entity.

dashed-line

A _____ contains at least all of the attribute names and characteristics for each table in the system.

data dictionary

The decision to store _____ attributes in database tables depends on the processing requirements and the constraints placed on a particular application.

derived

A(n) _____ is the set of possible values for a given attribute.

domain

A relationship is an association between _____.

entities

Knowing the minimum and maximum number of _____ occurrences is very helpful at the application software level.

entity

The CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. This is an example of _____ integrity.

entity

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

A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity.

false

Composite attributes make it easier to facilitate detailed queries.

false

Referential integrity and participation are both bidirectional, meaning that they must be addressed in both directions along a relationship.

false

Relationships between entities always operate in one direction.

false

Software vendors have adopted the Chen representation because of its compact representation.

false

The Crow's Foot notation easily identifies multivalued attributes.

false

The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity.

false

A _____ is the primary key of one table that has been placed into another table to create a common attribute.

foreign key

In organizations that generate large number of transactions, _____ are often a top priority in database design.

high processing speeds

In a database context, the word _____ indicates the use of the same attribute name to label different attributes.

homonym

A(n) _____ is an orderly arrangement used to logically access rows in a table.

index

Complex _____ requirements may dictate data transformations, and they may expand the number of entities and attributes within the design.

information

A(n) _____ only returns matched records from the tables that are being joined.

inner joins

Referential _____ dictates that the foreign key must contain values that match the primary key in the related table, or must contain null.

integrity

Database design is a(n) _____ process based on repetition.

iterative

In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable.

keys

According to Codd's _____ rule of relational databases, application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns).

logical data independence

A(n) _____ join links tables by selecting only the rows with common values in their common attribute(s).

natural

According to Codd's _____ rule of relational databases, if the system supports low-level access to the data, users must not be allowed to bypass the integrity rules of the database.

nonsubversion

Ideally, an entity identifier is composed of _____ attribute(s).

one

The existence of a(n) _____ entity indicates that its minimum cardinality is zero.

optional

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

_____ are especially useful when you are trying to determine what values in related tables cause referential integrity problems.

outer joins

If an employee within an EMPLOYEE entity has a relationship with itself, that relationship is known as a _____ relationship.

recursive

A _____ key is defined as a key that is used strictly for data retrieval purposes.

secondary

A _____ attribute is one that cannot be subdivided.

simple

When using the Crow's Foot notation, the associative entity is indicated by _____ relationship lines between the parents and the associative entity.

solid

If an entity can exist apart from all of its related entities, then it is existence-independent, and it is referred to as a(n) _____ entity.

strong

A _____ is any key that uniquely identifies each row.

superkey

When the specific cardinalities are not included on the diagram in Crow's Foot notation, cardinality is implied by the use of _____.

symbols

In a database context, a(n) _____ indicates the use of different names to describe the same attribute.

synonym

The _____ is actually a system-created database whose tables store the user/designer-created database characteristics and contents.

system catalog

A _____ relationship exists when three entities are associated.

ternary

A composite identifier is a primary key composed of more than one attribute.

true

A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.

true

Connectivities and cardinalities are established by concise statements known as business rules.

true

In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side must be loaded first.

true

In the entity relationship model, a table row corresponds to an entity instance.

true

In the original Chen notation, each attribute is represented by an oval with the attribute name connected to an entity rectangle with a line.

true

To implement a small database, a database designer must know the "1" and the "M" sides of each relationship and whether the relationships are mandatory or optional.

true

A _____ relationship exists when an association is maintained within a single entity.

unary

When two or more tables share the same number of columns, and when their corresponding columns share the same or compatible domains, they are said to be _____.

union-compatible

When you define a table's primary key, the DBMS automatically creates a(n) _____ index on the primary key column(s) you declared.

unique

A _____ entity has a primary key that is partially or totally derived from the parent entity in the relationship.

weak

The Crow's foot symbol with two vertical parallel lines indicates _____ cardinality.

(1,1)

In the entity relationship diagram (ERD), cardinality is indicated using the _____ notation, where max is the maximum number of associated entities and min represents the minimum number of associated entities.

(min, max)

The _____ relationship should be rare in any relational database design.

1:1

The _____ relationship is the "relational model ideal."

1:M

_____ expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity.

Cardinality

Character data can contain any character or symbol intended for mathematical manipulation.

False

In Chen notation, there is no way to represent cardinality.

False

In a natural join, the column on which the join was made occurs twice in the new table.

False

In implementation terms, an entity is existence-dependent if it has a mandatory primary key.

False

Only a single attribute, not multiple attributes, can define functional dependence.

False

The Crow's Foot notation is less implementation-oriented than the Chen notation.

False

The SELECT operator yields a vertical subset of a table.

False

The entity relationship model (ERM) is dependent on the database type.

False

The idea of determination is unique to the database environment.

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

The row's range of permissible values is known as its domain.

False

Date attributes contain calendar dates stored in a special format known as the _____ date format.

Julian

The conceptual model can handle _____ relationships and multivalued attributes.

M:N

The entity relationship model uses the associative entity to represent a(n) _____ relationship between two or more entities.

M:N

_____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.

M:N

The _____ constraint can be placed on a column to ensure that every row in the table has a value for that column.

NOT NULL

_____ returns only the attributes requested, in the order in which they are requested.

PROJECT

_____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false.

Predicate

To be considered minimally relational, the DBMS must support the key relational operators _____, PROJECT, and JOIN.

SELECT

_____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.

SELECT

A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures.

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

An entity in the entity relationship model corresponds to a table in the relational environment.

True

As rare as 1:1 relationships should be, certain conditions absolutely require their use.

True

Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used.

True

Each table in a relational database must have a primary key.

True

If the attribute (B) is functionally dependent on a composite key (A) but not on any subset of that composite key, the attribute (B) is fully functionally dependent on (A).

True

In the Chen and Crow's Foot notations, an entity is represented with a rectangle containing the entity's name.

True

RDBMSs enforce integrity rules automatically.

True

Relational algebra defines the theoretical way of manipulating table contents using relational operators.

True

The DIFFERENCE operator subtracts one table from the other.

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 practical significance of taking the logical view of a database is that it serves as a reminder of the simple file concept of data storage.

True

You can think of a table as a persistent representation of a logical relation.

True

The _____ notation of entity-relationship modelling can be used for both conceptual and implementation modelling.

UML