Database Models

Flat File The most basic way to organize data is as a flat file. You can think of this as a single table with a large number of records and fields. Everything you need is stored in this table, or flat file.

Hierarchical DBMS In a hierarchical DBMS one data item is subordinate to another one. This is called a parent-child relationship. The hierarchical data model organizes data in a tree-like structure.

Network DBMS In a network DBMS every data item can be related to many others ones. The database structure is like a graph. This is similar to the hierarchical model and also provides a tree- like structure. However, a child is allowed to have more than one parent.

Relational DBMS In a relational DBMS all data are organized in the form of tables. A relational DBMS uses multiple tables to organize the data. Relationships are used to link the various tables together. Relationships are created using a field that uniquely identifies each record

Object-Oriented DBMS The previous DBMS models work primarily with text and numbers. Object-oriented databases are able to handle many newer data types, such as images, audio and video. These data items are the objects stored in the database.

Lesson Summary There are a number of different models of database management systems. Flat files are like a single, very large table. This only works for very simple data. Hierarchical databases use parent-child relationships in a tree-like structure. This only works for data that is inherently hierarchical in nature.

Network databases are more like a cobweb structure, with numerous network links between data elements. This quickly gets very complicated. Relational databases organize data in tables, and these are linked together using table relationships. This is by far the most widely used database model since it is very effective..

Object-oriented databases are well suited to store multimedia data as objects instead of using a tabular structure