Data Analysis & Design

Task 01
a.
      1.1 Data models.
A data model in software engineering is an abstract model that describes how data is represented and accessed. Data models formally define data elements and relationships among data elements for a domain of interest. Data model explicitly determines the meaning of data, which in this case is known as structured data. Typical applications of data models include database models, design of information systems, and enabling exchange of data. Usually data models are specified in a data modeling language. A data model can be sometimes referred to as a data structure, especially in the context of programming languages. Data models are often complemented by function models, especially in the context of enterprise models.
Managing large quantities of structured and unstructured data is a primary function of information systems. Data models describe structured data for storage in data management systems such as relational databases. They typically do not describe unstructured data, such as word processing documents, email messages, pictures, digital audio, and video.
Data models support data and computer systems by providing the definition and format of data. If this is done every time across systems then compatibility of data can be achieved. If the same data structures are used to store and access data then different applications can share data. The results of this are indicated above. However, systems and interfaces often cost more than they should, to build, operate, and maintain.
There are seven data models, there are;
  * Hierarchical Model
  * Network Model
  * Relational Model
  * Object/Relational Model
  * Object-Oriented Model
  * Semi structured Model
  * Associative Model
Hierarchical Model
The hierarchical data model organizes data in a tree structure. There is a hierarchy of parent and child data segments. This structure implies that a record can have repeating information, generally in the child data... [continues]

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