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The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS). The term " schema " refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases ).
A conceptual schema or conceptual data model is a high-level description of informational needs underlying the design of a database. [1] [2] It typically includes only the core concepts and the main relationships among them. This is a high-level model with insufficient detail to build a complete, functional database. [3]
The database design documented in these schemas is converted through a Data Definition Language, which can then be used to generate a database. A fully attributed data model contains detailed attributes (descriptions) for every entity within it. The term "database design" can describe many different parts of the design of an overall database ...
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 notion of a three-schema model was first introduced in 1975 by the ANSI/X3/SPARC three level architecture, which determined three levels to model data. [1]The three-schema approach, or three-schema concept, in software engineering is an approach to building information systems and systems information management that originated in the 1970s.
Database design is the organization of data according to a database model. The designer determines what data must be stored and how the data elements interrelate. With this information, they can begin to fit the data to the database model. [1] A database management system manages the data accordingly.
Database model for MediaWiki 1.28.0 (2017) Different types of database models A database model is a type of data model that determines the logical structure of a database.It fundamentally determines in which manner data can be stored, organized and manipulated.
The external schemas describe the different external views of the data, and there may be many external schemas for a given database. The conceptual schema describes all the data items and relationships between them, together with integrity constraints (later). There is only one conceptual schema per database. The internal schema at the lowest ...