CS409 Assignment 2 Solution and Discussion

[zareen]

@zareen said in CS409 Assignment 2 Solution and Discussion:

Consider the given below the ERD

[zareen]

@zaasmi said in CS409 Assignment 2 Solution and Discussion:

Consider the given below the ERD of a scenario given here. You are required to convert it into its logical model.

Logical data model example

[zaasmi]

@zaasmi said in CS409 Assignment 2 Solution and Discussion:

Logical ERD is a detailed version of a Conceptual ERD. A logical ER model is developed to enrich a conceptual model by defining explicitly the columns in each entity and introducing operational and transactional entities.

A logical data model describes the data in as much detail as possible, without regard to how they will be physical implemented in the database. Features of a logical data model include:

Includes all entities and relationships among them.
All attributes for each entity are specified.
The primary key for each entity is specified.
Foreign keys (keys identifying the relationship between different entities) are specified.
Normalization occurs at this level.
The steps for designing the logical data model are as follows:

Specify primary keys for all entities.
Find the relationships between different entities.
Find all attributes for each entity.
Resolve many-to-many relationships.
Normalization.
The figure below is an example of a logical data model.

[zaasmi]

@zaasmi said in CS409 Assignment 2 Solution and Discussion:

Consider the given below the ERD of a scenario given here. You are required to convert it into its logical model.

Logical ERD is a detailed version of a Conceptual ERD. A logical ER model is developed to enrich a conceptual model by defining explicitly the columns in each entity and introducing operational and transactional entities.

[zareen]

@zaasmi said in CS409 Assignment 2 Solution and Discussion:

What is the purpose of a logical data model?

Logical data models add further information to the conceptual model elements. It defines the structure of the data elements and set the relationships between them. The advantage of the Logical data model is to provide a foundation to form the base for the Physical model.

[zaasmi]

What is the purpose of a logical data model?

[Doll Doll]

@zaasmi said in CS409 Assignment 2 Solution and Discussion:

How do you convert logical data model to physical?

The logical data model defines the structure of the data elements and set the relationships between them. The physical Data Model describes the database-specific implementation of the data model.

[zaasmi]

How do you convert logical data model to physical?