Conceptual Data Model Design, Logical Data Model Design, and physical data model design are three major steps for database and data warehouse model design.
In the data warehouse field, there is a concept called conceptual data model, which is generally translated as "conceptual data model ".
The conceptual data model is an end user's opinion on data storage and reflects the comprehensive information requirements of end users. It describes enterprise-level data requirements in the form of data, data classes represent several main types of data that are naturally integrated in the business environment.
The concept data model includes the relationship between important entities and entities. The conceptual data model does not include the attributes of an object, nor does it need to define the primary key of an object. This is the main difference between a conceptual data model and A Logical Data Model.
The goal of the conceptual data model is to unify business concepts and serve as a bridge between business personnel and technical personnel to determine the highest level of relationships between different entities.
In the design process of some data models, the conceptual data model is designed together with the Logical Data Model.
In the data warehouse field, there is a concept called the Logical Data Model. Chinese characters are generally translated as "Logical Data Models ".
The Logical Data Model reflects the point of view of the system analysis designer on data storage and further decomposes and refines the conceptual data model. The Logical Data Model is determined based on business rules. It provides a basic blueprint for the relationship between business objects, data items of business objects, and business objects.
The content of the Logical Data Model includes all objects and relationships. The attributes of each object are determined, the primary keys of each object are defined, and the foreign keys of the objects are specified, which must be normalized.
The goal of the Logical Data Model is to describe the data in as much detail as possible, but it does not consider how the data is physically implemented.
Logical Data Modeling not only affects the direction of database design, but also indirectly affects the performance and management of the final database. If you invest enough in implementing the Logical Data Model, there are many options to choose when designing the physical data model.
In the data warehouse field, there is a concept called physical data model, which is generally translated as "Physical Data Model" in Chinese ".
The physical data model is based on the Logical Data Model. It designs the database architecture based on various technical implementation factors to truly store data in the database.
The content of the physical data model includes determining all tables and columns, defining foreign keys for determining the relationship between tables, and sending the contents such as paradigm based on user requirements. In terms of physical implementation, physical data models and logical data models may be significantly different.
The goal of the physical data model is to specify how to use the database mode to implement the Logical Data Model and truly store data.