What is Data Model?. Data Model can be defined as abstract model whose purpose is to describe how data can be used and represented effectively. A data model is a picture or description which shows how data are to be arranged to serve a specific purpose it determines the structure of data and the information is to be contained, how the information will be used and how items in database will be related to each other.
Types of data model
- Database model
- Data structure diagram
- Entity-relationship model
- Geographic data model
- Generic data model
- Semantic data model
Database Model: A database model is specification describing how a database is structured and used.
Types of Database Model
- Flat Model: This consists of a single two-dimensional array of data element where every member of column and row are assumed to be related to one table with fields to represent all parameters.
| Name | Student ID | Age Address |
- Hierarchical Model: Here data are organized into a tree – like structure showing a single upward link in each record. Each branch of the hierarchy represents a number of related records.
- Network Model: This model organizes data using two fundamental constructs called record and sets. Records contain fields and set define one – to – many relationships between records, i.e. one owner, many members. This handles many to many relationships and allows a record to have more than one parent.
- Relational Model: This represents data as relations or tables i.e. the data and the relationship among data are represented by a collection of tables. Each table has multiple columns and each column has a unique.
- Object – Relational Model (ORM): This is designed to provide a relational database management that allows developer to integrate databases with their data types and method. It is similar to relational database but objects are directly supported in database schemas and in query language.
- Star Schema: This database model provides fast response to queries and forms the ideal source for cube structure. It enables faster retrieval from the database.
- Data Structures Diagram: This is a diagram and data models used to describe conceptual data model by providing graphical notation which document the entities and their relationship as well as constraint that connect to them.
It is a conceptual modeling tool used to document the different structured that make up a system such as a database or an application.
- Entity – Relationship Model (ER): This is a graphical representation of entities and their relationship to each other written database or information system
- Geographic Data Model: This model is used to collect, analyze and present information describing the physical and logical properties of the geographic world.
Examples:
Vector data model represent geography as collection of points, lines and polygon. The master data model represents geography as cell matrixes that store numeric values.
- Generic Data Model: This model is developed as an approach to solve some problems of conventional data models. Examples different models usually produce different conventional data models of the same domain and this can lead to difficulty in bringing the models of different people together and is an obstacle for data exchange and data integration. Here, all the attributes are separated from the object and saved in different table.
- Semantic Data Model: This is a way of structuring data to represent it in a logical way. It is a conceptual data model that includes semantic information that adds a basic meaning to the data and the relationship that lies between them.
Evaluation
- What is data model
- List the types of data model
- Define the following
- Entry-Relational Model
- Geographic Data Model
- Generic Data Model
- Semantic Data Model