Notes for Degree Students

I Bcom(CA) Notes   DBMS Notes

  CHAPTER-2 Data Models Data Modeling and Data Models: Data model: A data model is a collection of concepts that can be used to describe the structure of a database Data modeling in the first step in designing a database refers to the process of creating a specific data model for a problem.         A model is an abstraction of a real world object. A data model represents data structures and their characteristics, relations, constraints and transactions.         Data model is an iterative process we start with a simple understanding of the problem increases, and finally design a database in a specific database model. Importance of Data Models: 1.     Data Model can facilitate interaction among the designer, the application programmer and the end user. 2.     Applications are used to transform data into information. But data are viewed in different ways by different...