Database Design Semester I Quiz

<p>Sub-entities inherit both shared and their own unique attributes. (A)</p> Signup and view all the answers

<p>Sub-entities can engage in relationships defined by the general entity. (C)</p> Signup and view all the answers

<p>Sub-entity A can be classified as both sub-entity A and B simultaneously. (C)</p> Signup and view all the answers

<p>Exclusive Generalization (A)</p> Signup and view all the answers

<p>The higher-level entity that encapsulates shared attributes. (D)</p> Signup and view all the answers

<p>Specialisation and generalisation (D)</p> Signup and view all the answers

<p>Union of multiple lower-level entity sets (B)</p> Signup and view all the answers

<p>Use unique identifiers as attributes in related sets (D)</p> Signup and view all the answers

<p>It results in redundant data (B)</p> Signup and view all the answers

<p>It treats relationship sets as entity sets (B)</p> Signup and view all the answers

<p>Designating primary key attributes as attributes of the relationship (B)</p> Signup and view all the answers

<p>As a distinct entity set with its attributes (A)</p> Signup and view all the answers

<p>Lower-level sets obtain attributes from higher-level sets (B)</p> Signup and view all the answers

<p>Sub entities must be mutually exclusive. (C)</p> Signup and view all the answers

<p>A high-level entity cannot exist without specialized entities. (A)</p> Signup and view all the answers

<p>A high-level entity can exist independently of sub entities. (B)</p> Signup and view all the answers

<p>Specializations can be either disjoint or overlapping. (D)</p> Signup and view all the answers

<p>An entity must be inserted into at least one lower-level entity set. (A)</p> Signup and view all the answers

<p>Generalization enforces strict attribute requirements. (D)</p> Signup and view all the answers

<p>All combinations are allowed. (D)</p> Signup and view all the answers

<p>It indicates a total generalization. (D)</p> Signup and view all the answers

<p>It enables additional information about the phone to be stored. (B)</p> Signup and view all the answers

<p>To describe an action occurring between entities. (D)</p> Signup and view all the answers

<p>It does not allow for information about the phone itself. (B)</p> Signup and view all the answers

<p>By converting them into multiple binary relationships. (D)</p> Signup and view all the answers

<p>It may provide a clearer representation without losing details. (B)</p> Signup and view all the answers

<p>It efficiently organizes data into simpler relationships. (D)</p> Signup and view all the answers

<p>An entity set denotes objects with similar characteristics. (B)</p> Signup and view all the answers

<p>It facilitates the modeling of shared ownership. (A)</p> Signup and view all the answers

Separating sub-groups inside a main group of entities.

Connecting entities with common attributes in a higher-level entity.

Sub-entities inherit attributes from the general entity.

Sub-entities can participate in relationships of the general entity.

A sub-entity can belong to multiple sub-types.

A sub-entity can belong to only one sub-type.

Every entity in the super-type must be in at least one sub-type.

Some entities in the super-type may not be in any sub-types.

Every entity in the higher level must be categorized in at least one sub-type.

Disjoint generalizations ensure that an entity can belong to only one sub-type, while overlapping generalizations allow entities to belong to multiple sub-types.

Every entity in the higher-level category must belong to at least one sub-type. It's impossible to be in the higher level without being in a sub-type.

Partial generalizations allow entities to exist in the higher-level category without being in a sub-type, whereas Total generalizations require every entity to be in at least one sub-type.

Attributes of a general entity are passed down to its more specific sub-entities.

Treating relationships and their associated entities as higher-level entities that can participate in other relationships.

Attributes that duplicate information already present in another table or relationship.

Deciding whether a concept should be represented as a separate entity set or as an attribute of another entity.

Unique identifiers of related entities (primary keys) should not be repeated as attributes within the relationship itself.

Avoid using a unique identifier of one entity set as an attribute of another entity set directly.

Deciding whether a concept is better represented as an entity (a distinct object with its own properties) or as an attribute (a property of another entity).

An attribute that can hold multiple values for a single entity. For example, a person can have multiple phone numbers.

Using an entity allows for storing additional information about the concept and modeling situations where an entity can have multiple instances of the concept, while using an attribute restricts the entity to having only one instance.

Treating a concept as an entity provides more generality and flexibility, as it can be used to store additional information and model situations with multiple instances.

Represents an association between two or more entity sets, describing the types of interactions that occur between them.

A relationship set involving two entity sets.

A relationship between three or more entity sets.

Representing a non-binary relationship using binary relationships by introducing a new entity set and creating binary relationships between the new entity and the original entities involved.