What is the difference between logical and physical models?
The main difference between Logical and Physical Data Model is that Logical data models help to define the data elements and their relationships, while the physical data models help to design the actual database based on the requirements gathered during the logical data modelling.
What is physical model and logical model?
Physical data models are used to visualize the physical structure of databases and data files. Logical data models are used to visualize data entities, attributes, keys, and relationships.
What is the difference between physical model and conceptual model?
It consists of concepts used to help people know, understand, or simulate a subject the model represents. It is also a set of concepts. In contrast, physical models are physical objects, such as a toy model that may be assembled and made to work like the object it represents.
In what ways does the logical model differ from the conceptual model?
The main difference between conceptual and logical data model is that conceptual data model represents entities and their relationships while logical data model provides more details than the conceptual data model including attributes, primary and foreign keys other than the entities and the relationships.
How does logical design differ from physical design?
The logical design is more conceptual and abstract than the physical design. In the logical design, you look at the logical relationships among the objects. In the physical design, you look at the most effective way of storing and retrieving the objects. Your design should be oriented toward the needs of the end users.
What is difference between logical and physical data independence?
The physical data independence is basically used to separate conceptual levels from the internal/physical levels….Difference between Physical and Logical Data Independence :
| Physical Data Independence | Logical Data Independence |
|---|---|
| It is easy to retrieve. | It is difficult to retrieve because the data is mainly dependent on the logical structure of data. |
What is LDM and PDM?
The Logical Data Model (LDM) is derived from the Conceptual Data Model (CDM).The CDM consists of the major entity sets and the relationship sets, and does not state anything about the attributes of the entity sets.The LDM consists of the Entity Sets, their attributes, the Relationship sets, the cardinality, type of …
What are the three main types of models?
Contemporary scientific practice employs at least three major categories of models: concrete models, mathematical models, and computational models.
What is the difference between logical and physical data models What are some things one might include that the other does not?
Logical database modeling does not include indexes and constraints; the logical database model for an application can be used across various database software and implementations; whereas physical database modeling is software and hardware specific and has indexes and constraints.
What is modeling differentiate between physical and conceptual modeling explain with example?
The conceptual model is to establish the entities, their attributes, and their relationships. 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.
What is a logical model design?
A logic model is a graphic depiction (road map) that presents the shared relationships among the resources, activities, outputs, outcomes, and impact for your program. It depicts the relationship between your program’s activities and its intended effects.
What is logical and physical independence?
Logical data independence: The ability to change the logical (conceptual) schema without changing the External schema (User View) is called logical data independence. Physical data independence: The ability to change the physical schema without changing the logical schema is called physical data independence.