DBMS Organization

 

Hierarchical Database

  1. Similar to an organizational chart of a business.
  2. Fields or records are structured in nodes (modules).
  3. Nodes are points connected like branches of an upside-down tree.
  4. Nodes farther down the system are subordinate to the ones above.
  5. Each entry has one parent node directly above it, and may have one, none, or several child nodes directly below it.
  6. A node can be both a parent and a child.
  7. This type of organization is harder to update, especially when a node is added or deleted.

 

 

Network Database

  1. Hierarchical arrangement of nodes but each child node may have more than one parent.
  2. There are additional connections between parent nodes and child nodes called pointers.
  3. Pointers make it possible to reached a node through more than one path.
  4. More flexible and more efficient than the hierarchical arrangement.

 

 

Relational Database

  1. The most flexible type of database organization.
  2. Elements are stored in different tables, each of which consists of rows and columns.
  3. Each table is called a relation.
  4. All related tables must have a key field.
  5. Makes it possible to link data from two or more database files into meaningful information.
  6. Data can be easily added, deleted, and modified.
  7. Examples of relational databases for microcomputers are dBase, Access, Paradox and RBase.
  8. Also used on mainframe and minicomputer Systems.

 

 

Object-Oriented Database

  1. A new, more flexible type of data base organization.
  2. Able to keep track of structured data such as names, address, phone numbers, etc.
  3. Able to keep track of unstructured data such as photographs, graphics, audio and video.

 

 

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