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Logical database model and Relational database management system-computer world

 Logical Database model

The logical database models are used in describing data at the conceptual and view level.However in contrast to conceptual database models, these model are to specify the overall logical structure of the database .These model are also known as record based logical database models. In the record based logical database models, the database is structured in fixed format re-cred of different types.Each record type define a fixed numbers of fields, or attributes an each field is of a fixed length.

Relational database management system

Relational database management system(RDBMS) is a software package used to store and retrieve data that is organised in the form of tables. Relational database management system, where all data are kept in tables or relations. Relational database management system are much more flexible and easy to use, in the comparison to other models.


A Relational database management system(RDBMS) has following properties : 

  1. It store data in the form of table.
  2. It support the concepts of null value. 
  3. It does not require the user to understand it's physical implementation. 

A table should contain the following properties : 

  1. All rows in a table should be distinct, duplicate row are not allowed. 
  2. Each column should be assigned with a distinct heading. 
  3. The rows and the column of a table can be viewed in any sequence at any time without affecting the information. 



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