Physical schema
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A physical data model (or
As of 2012[update] seven main databases dominate the commercial marketplace:
Physical schema
Physical schema is a term used in
In the
Subsequently[citation needed] the internal schema was recognized to have two parts:
The logical schema was the way data were represented to conform to the constraints of a particular approach to database management. At that time the choices were hierarchical and network. Describing the logical schema, however, still did not describe how physically data would be stored on disk drives. That is the domain of the physical schema. Now logical schemas describe data in terms of relational tables and columns, object-oriented classes, and XML tags.
A single set of tables, for example, can be implemented in numerous ways, up to and including an architecture where table rows are maintained on computers in different countries.
See also
- Database schema
- Conceptual data model
- Logical data model
References
- National Archives.
- ^ rothja. "Overview of SQL Server on Linux - SQL Server". docs.microsoft.com. Retrieved 2019-04-28.
External links
- FEA Consolidated Reference Model Document (whitehouse.gov) Oct 2007.