Question

 

Q1: Data Modelling is the primary step in the process of database design. Compare and contrast Conceptual data model versus Physical data model. Illustrates with help of example to list down data (entities), relationship among data and constraints on data.

Q2: What strategic competitive benefits do you see in a company’s use of extranets?

Answer 1

Data modeling is a technique to document a software system using entity relationship diagrams (ER Diagram) which is a representation of the data structures in a table for a company’s database. It is a very powerful expression of the company’s business requirements. Data models are used for many purposes, from high-level conceptual models, logical to physical data models and typically represented by the entity-relationship diagram. It serves as a guide used by database analysts and software developers in the design and implementation of a system and the underlining database.

Physical data model

Physical ERD represents the actual design blueprint of a relational database. A physical data model elaborates on the logical data model by assigning each column with type, length, nullable, etc. Since a physical ERD represents how data should be structured and related in a specific DBMS it is important to consider the convention and restriction of the actual database system in which the database will be created. Make sure the column types are supported by the DBMS and reserved words are not used in naming entities and columns.

Logical data 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. Although a logical data model is still independent of the actual database system in which the database will be created, you can still consider that if it affects the design.

The Conceptual Model Is To Establish The Entities, Their Attributes, And Their Relationships.

The Physical Data Model Describes The Database-Specific Implementation Of The Data Model.

You may read more at:

https://online.visual-paradigm.com/knowledge/visual-modeling/conceptual-vs-logical-vs-physical-data-model/

Particularly in the business-to-business market, an extranet cangive your company an edge over the competition and save you money by streamlining traditional business functions and cutting overhead costs. Extranets offer small businesses many other advantages:

Increased productivity.

Reduced margin of error.

Flexibility.

Timely and accurate information.

Shorter time to market.

Reduced inventory.

Build customer loyalty.

You may read more at:

https://www.google.com/amp/s/www.allbusiness.com/the-benefits-of-an-extranet-1283-1.html/amp