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Data Modeling Link

The two types of Data Models techniques are

1. Entity Relationship (E-R) Model
2. UML (Unified Modelling Language)

There are mainly three different types of data models:

• Conceptual: This Data Model defines WHAT the system contains. This model is typically created by Business stakeholders and Data Architects. The purpose is to organize, scope and define business concepts and rules.
• Logical: Defines HOW the system should be implemented regardless of the DBMS. This model is typically created by Data Architects and Business Analysts. The purpose is to developed technical map of rules and data structures.
• Physical: This Data Model describes HOW the system will be implemented using a specific DBMS system. This model is typically created by DBA and developers. The purpose is actual implementation of the database.

What is Data Modeling Link

• “A physical data model represents the actual structure of a database—tables and columns, or the messages sent between computer processes. Here the entity types usually represent tables, and the relationship type lines represent the foreign keys between tables.”
• “A logical data model is a fully attributed data model that is fully normalized. Fully attributed means that the entity types have all the attributes and relationship types for all the data that is required by the application(s) it serves. It may include:
• Restrictions on the data that can be held
• Rules and derived data that are relevant to the processes of the application(s) the logical data model serves.”
• “A conceptual data model is a model of the things in the business and the relationships among them, rather than a model of the data about those things. So in a conceptual data model, when you see an entity type called car, then you should think about pieces of metal with engines, not records in databases. As a result, conceptual data models usually have few, if any, attributes.”

Data Modeling Explained in 10 Minutes or Less Link