Memory and Database

Sunday, November 05, 2006

Database Models

• Hierarchical database
• Network database
• Relational database
• Object Oriented
• Object-relational

Hierarchical Database
In a hierarchical data model, data is organized into a tree-like structure. The structure allows repeating information using parent/child relationships: each parent can have many children but each child only has one parent.




Network Database
Where the hierarchical model structures data as a tree of records, with each record having one parent record and many children, the
network database model allows each record to have multiple parent and child records, forming a lattice structure.

Relational Database
The relational database represents each record type in tabular form, and all records of the same type are contained in a single table.




Object Oriented Database
In contrast to a relational database where a complex data structure must be flattened out to fit into tables or joined together from those tables to form the in-memory structure, object oriented databases have no performance overhead to store or retrieve a web or hierarchy of interrelated objects. For example, at MIAD we have the MOODLE, which is an acronym for Modular Object-Oriented Dynamic Learning Environment!




Source:
Database Concepts. WENT1999
Mysql & mSql O’Reilly
http://www.csie.ndhu.edu.tw/

0 Comments:

Post a Comment

<< Home