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Physical data independence: The ability to change the physical schema without changing the logical schema is called physical data independence. For example, a change to the internal schema, such as using different file organization or storage structures, storage devices, or indexing strategy, should be possible without having to change the ...
Physical data model options. [1] A physical data model (or database design) is a representation of a data design as implemented, or intended to be implemented, in a database management system. In the lifecycle of a project it typically derives from a logical data model, though it may be reverse-engineered from a given database implementation.
The four views of the model are logical, development, process and physical view: The four views of the model are concerned with : Logical view: is concerned with the functionality that the system provides to end-users. Development view: illustrates a system from a programmers perspective and is concerned with software management.
The four views of the model are logical, development, process, and physical view. In addition, selected use cases or scenarios are used to illustrate the architecture serving as the 'plus one' view. Hence, the model contains 4+1 views: [1] Logical view: The logical view is concerned with the functionality that the system provides to end-users.
A logical data model or logical schema is a data model of a specific problem domain expressed independently of a particular database management product or storage technology (physical data model) but in terms of data structures such as relational tables and columns, object-oriented classes, or XML tags.
Implementation of one conceptual data model may require multiple logical data models. The last step in data modeling is transforming the logical data model to a physical data model that organizes the data into tables, and accounts for access, performance and storage details. Data modeling defines not just data elements, but also their ...
It allows independent customized user views: Each user should be able to access the same data, but have a different customized view of the data. These should be independent: changes to one view should not affect others. It hides the physical storage details from users: Users should not have to deal with physical database storage details.
The data architect breaks the subject down by going through three traditional architectural stages: Conceptual - represents all business entities. Logical - represents the logic of how entities are related. Physical - the realization of the data mechanisms for a specific type of functionality.