INST 311 Lecture Notes - Lecture 4: Database Model, Database, Relational Model
30 Aug 2018
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Document Summary
Data models define how the logical structure of a database is modeled. Data models are fundamental entities to introduce abstraction in a dbms. Data models define how data is connected to each other and how they are processed and stored inside the system. The very first data model could be flat data-models, where all the data used are to be kept in the same plane. Earlier data models were not so scientific, hence they were prone to introduce lots of duplication and update anomalies. Entity-relationship (er) model is based on the notion of real-world entities and relationships among them. While formulating real-world scenario into the database model, the er model creates entity set, relationship set, general attributes and constraints. Er model is best used for the conceptual design of a database. Entity an entity in an er model is a real-world entity having properties called attributes . Every attribute is defined by its set of values called domain .
