Data Analysis - EER

What is the main difference between ERD and EER?

• EER includes features like specialization and generalization

• ERD is more advanced than EER

• EER is not used in analysis

• ERD supports inheritance

What does Specialization mean?

• Merging multiple entities into one

• Dividing a general entity into sub-entities

• Removing attributes

• Adding new relations

In Generalization, what happens?

• Combining similar entities into a general one

• Turning relations into entities

• Removing duplicated attributes

• Creating temporary tables

Which of the following is an example of Generalization?

• موظف ← إداري، فني

• كلب ← حيوان

• سيارة ← لون، نوع

• عميل ← طلبات

In Disjoint Specialization:

• An entity can belong to more than one subclass

• An entity belongs to only one subclass

• There are no common attributes

• It’s not allowed in EER

Overlapping Specialization allows:

• كيان واحد يكون في أكتر من subclass

• كيان لازم يكون في subclass واحد فقط

• حذف الـ attributes

• فصل العلاقات عن الكيانات

Inheritance in EER means:

• An entity inherits attributes from a super entity

• Relation between two entities

• Copying relationships

• Ignoring foreign keys

EER allows more complex modeling than ERD

• True

• False

Specialization = combining multiple entities into one.

• True

• False

Generalization is used when different entities share common attributes

• True

• False