Object and relational DBMS

Details

For systems with an expanded relational data model the most different terms are used. At first the term expanded relational DBMS was applied, however more informative term - object and relational DBMS, or ORSUBD which contains the instruction on use of a concept an object is used in recent years. Rub maintaining kompaniiv the development areas the database management system, namely Oracle, Informix and IBM, expanded the systems to object and relational level though functionality of their solutions differs a little. The concept of ORSUBD as combinations of OOSUBD and a RDBMS, is very attractive due to use of knowledge and experience which were accumulated during operating time with a RDBMS.

Advantages

Main advantages of an expanded relational model are repeated and sharing of components. For example, in the application use of data of space type, the representing points, lines, and polygons, with the related functions which calculate distance between points, distance between a point and the line can be necessary, check existence of a point in a polygon, etc. At the correct design taking into account new opportunities similar approach allows the organizations to use advantages of new expansions in the evolutionary way without loss of the advantages got from use of components and functions of already existing database.

Shortcomings

Obvious lack of approach using ORSUBD are the complexity and the related raised expenses. A scope and the clarity inherent in a relational model is lost when using similar types of expansion. Some consider that the RDBMS expansions are intended for the insignificant number of applications, and in the last optimal performance when using of the available relational technology cannot be reached. And many others, up to terminology.

Examples of ORSUBD

Oracle Database

Microsoft SQL Server

PostgreSQL

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