Review Test 3

A(n) ________ class is a class that has no direct instances but whose descendants may have direct instances.

Abstract

Which relation is created with a composite primary key using the primary keys of the related entities, plus any non-key attributes associative entity of the relationship or associative entity?

Associative Entity

A ________ relationship is a relationship between instances of two entity types and is the most common type of relationship encountered in data modeling.

Binary

________ is NOT a valid type of partitioning method in relational database products.

Boundary

The ________ defines the number of instances of entity B that can (or must) be associated with each instance of entity A.

Cardinality

A(n) ________ is an attribute whose value can be computed from related attribute values.

Derived Attributes

A null value is the value a field will assume unless an explicit value is entered for the field.

False

A physical data model is a detailed model that captures the overall structure of organizational data that is independent of any database management system or other implementation considerations.

False

A relation is in first normal form if every non-primary key attribute is functionally dependent on the whole primary key.

False

A ternary relationship is a relationship between instances of two entity types and is the most common type of relationship encountered in data modeling.

False

An aggregation is an association between the instances of one or more entity types that is of interest to the organization.

False

An entity type that associates the instances of only one type and contains attributes that are peculiar to the relationship between those entity instances.

False

De-normalization is a process for converting complex data structures into simple, stable data structures.

False

In a range control, only alphabetic data may have a limited set of permissible values.

False

Range partitioning combines range and hash partitioning by first segregating data by ranges on the designated attribute, and then within each of these partitions, it further partitions by hashing on the designated attribute.

False

While representing an entity, each non-key attribute of the entity type becomes a key attribute of the relation.

False

A binary one-to-many (1:N) relationship in an E-R diagram is represented by adding the primary key attribute (or attributes) of the entity on the one side of the relationship as a(n) ________ in the relation that is on the many side of the relationship.

Foreign Key

An entity ________ is a single occurrence of an entity type.

Instance

In ________ normal form, each non-primary key attribute is identified by the whole key (what we call full functional dependency).

Logical

________ is NOT a valid degree of the relationship.

N-Ary

The key should be ________; that is, no attribute in the key can be deleted without destroying its unique identification.

Non-Redundant

A(n) ________ is an attribute that may not have a value for every entity instance.

Optional attribute

A ________ table is a named set of rows and columns that specifies the fields in each row of the table.

Physical

What unique characteristic(s) distinguish(es) each object from other objects of the same type?

Primary Key

Which relation is created with primary key and non-key attributes only?

Regular Entity

In a relation, the sequence of columns can be interchanged without changing the meaning or use of the ________.

Relation

Each ________ of a relation corresponds to a record that contains data values for an entity

Row

A ________ is an entity type that is meaningful to the organization and that shares common attributes or relationships distinct from other sub-groupings.

Subtype

In some situations, two or more attributes may have different names but the same meaning, as when they describe the same characteristic of an entity. Such attributes are called ________.

Synonyms

In ________ normal form, non-primary key attributes do not depend on each other (what we call no transitive dependencies).

Third

A ternary relationship is a simultaneous relationship among instances of ________ entity type(s).

Three

The ________ rule specifies that each entity instance of the super-type must be a member of some subtype of the relationship.

Total Specialization

A supertype is a generic entity type that has a relationship with one or more subtypes.

True

An entity has its own identity that distinguishes it from each other entity.

True

The technique of hiding the internal implementation details of an object from its external view is known as encapsulation.

True

When merging relations that contain synonyms, we should obtain, if possible, agreement from users on a single standardized name for the attribute and eliminate the other synonym.

True

An entity ________ is a collection of entities that share common properties or characteristics.

Type

A recursive relationship is also known as a ________ relationship.

Unary

Which relation is created by placing the primary key of either entity in the relation for the other entity or by doing this for both entities?

Unary 1:1 relationship

Which relation is created with a composite primary key (which includes the primary key of the entity on which this weak entity depends) and non-key attributes?

Weak Entity

Which business rule specifies that each instance of an entity type must have a unique identifier that is not null?

Entity Integrity

The most common format used for data modeling is ________ diagramming.

Entity Relationship

A(n) ________ is the data manipulation operation (insert, delete, or update) that initiates the operation

Event